help-with-linux-sbcs

[civic rune]

Ah ok thanks!

[robust quail]

I have a RPi4 with the official case fan connected to GPIO14. Is there a way to see the fan status like Is it On/Off, What's the PWM of the fan when it was On?

[young sage]

The fan can be controlled from the raspi-config utility. There is no tachometer reading so RPM status cannot be reported.

[fresh patrol]

I feel like the PWM freq should be accessible somewhere

[late holly]

I got the https://www.adafruit.com/product/3708 - What is the recommended image for this - Raspbian Wheezy? or something else? I m just getting started and want to get a basic system working. Also, I want to operate in headless mode. Any suggestions? pointers?

[ruby night]

I'd recommend the latest version of Raspberry Pi OS from here: https://www.raspberrypi.com/software/

use the "lite" version for headless

see this guide https://learn.adafruit.com/raspberry-pi-zero-creation/overview

[steady rose]

^^ that

[ruby night]

FYI -- the latest version of Raspberry Pi OS -- "bullseye" has a new driver for the Raspberry Pi Camera. The old raspistill and raspivid are gone -- replaced by libcamera-still and libcamera-vid -- be careful out there....

Lots of guides and examples will need to be updated....

more info here - https://www.raspberrypi.com/documentation/accessories/camera.html

[late holly]

Thanks @ruby night - I will check these

[steady rose]

@ruby night interesting. did not know that.

libcamera is still missing certain features, most notably Python bindings. 😦

[ruby night]

Still lots to learn.

[late holly]

The power supply connector for a Pi4 and Pi Zero WH (https://www.adafruit.com/product/3708) seem different. I am not able to use the Pi4 power supply with the Pi Zero WH. Can someone recommend a correct power supply with a right connector? or an adaptor?

[steady rose]

Pi 4 has USB C. Pi Zero's have Micro USB B. So you'll need to adapt.

you kind of want the opposite of this:
https://www.adafruit.com/product/4299

[robust quail]

The fan uses PWM, can I write a Python script to check PWM of that pin? I can write the code, i just want to know if I'm allowed to read it

[steady rose]

here's a power supply option:
https://www.adafruit.com/product/1995

[late holly]

Thanks @steady rose

[steady rose]

np. pi zero's are pretty easy to power. they aren't as hungry as the bigger models. could maybe even look around for an old phone charger.

[young sage]

underclocking could lower power consumption

[hardy plaza]

Though it should be noted that actually running a Pi at 5.0v is already underpowering it since their designed supply voltage is 5.1v. It works but only just works. If you use an even slightly underpowered USB source and it browns out under load you'll either see low-power warnings on your screen when using a desktop, or if the voltage drops below somewhere around 4.8v the Pi will reset.

So I generally recommend an official RPi power supply or an adjustable bench supply that can be tuned to 5.1v. The micro-B connector on the standard RPi wall wart fits all of the Pi models except the Pi 4, and costs around US$8, so it's a good investment.

[steady rose]

yep. good point. a lot of the adafruit ones are actually spec'd a bit higher just for that reason (and similar scenarios). that pid 1995 is actually 5.25V.

i seem to get by powering via a PC USB port also though. do that a lot for quick trouble shooting, since the USB ports are easily available.

but, yah, if you get the lightning bolt, etc. could be brown out issues.

and for that, cable quality matters too.

[hardy plaza]

Oh, I admit I often power a Pi via a USB source, but I also note that I generally get a constant stream of low-power warnings in the logs. And as you say, the cable can make a lot of difference, and lastly, the power ratings that are published are for the Pi itself.

If one is running a bunch of peripheral devices, or any that take a significant amount of power, it's important to add up all those values and use a power supply with a safe buffer above that total amount.

A very significant percentage of problems people have with the Pi are due to under-voltage power supplies and/or under-powering (wattage-wise) their systems, which causes brownouts and therefore under-voltage.

[civic rune]

for this reason I got an external power supply that can be trimmed up to 5.1V

[steady rose]

yep. i try the USB port trick with a larger pi and there are a lot of "under voltage warning" messages that pop up. so it's just for quick test/checks.

[civic rune]

yeah I got a 5V 21W power brick

[fresh patrol]

Yeah reading it should be no problem

[hardy plaza]

...which in theory supplies 4.2 amps. But it pays to be careful with the way these supplies are described, as if they have multiple sockets that's often the cumulative current of the whole supply, not the per-socket current. So if your supply was two sockets and actually provided 10.5 watts per socket a Raspberry Pi plugged into it would only have a rated power supply of 2.1A per socket, where 2 watts (400mA) is enough for most of the Pi models (apart from the Pi 4) running on their own. Which all sounds good until one considers that these power supplies are generally designed as battery chargers, so they don't always react well under load and may well brown out well before they get to their rated limits.

[solemn finch]

anyone know if the rpi imager will erase the whole sd card? or will it just write the image from the start?

[hardy plaza]

It always does the whole card, i.e., erase, partition, copy and validate.

[solemn finch]

oh bummer. ok

[hardy plaza]

Are you familiar with rsync?

[solemn finch]

that'll remove any python code you've been working on

I'm aware of it

[hardy plaza]

If it's your code it's in your home directory, correct?

[solemn finch]

I'm thinking about circuitpython on rpi

where the first partition would be boot and the second would be CIRCUITPY

[hardy plaza]

Are we talking about an SD card used for /boot and /rootfs on a Raspberry Pi, or an SD card used on a microcontroller?

[solemn finch]

an sd card used to boot circuitpython (not linux) on a raspberry pi

[hardy plaza]

Ah, interesting. So you're not running Linux at all?

[solemn finch]

correct

[hardy plaza]

I must admit that's a new one for me.

[solemn finch]

😄

[hardy plaza]

Okay, well, with two partitions you can mount the existing SD card on a desktop computer and use rsync to copy the contents of each partition to a directory on your desktop computer. You then have a backup, and can use rsync to re-copy back to a different SD card with the same partition structure.

Does that help?

[solemn finch]

that's not what I'm after. but knowing what the imager does is helpful

[hardy plaza]

Sorry couldn't be more help 😁

[solemn finch]

np

[late holly]

@solemn finch - I would also be interested in using my Pi Zero W as circuit python. Can you share any pointers on the procedure for this?

[solemn finch]

I don't have Zero 1 support going yet

keep an eye out for more info in the next month or so

[late holly]

@solemn finch - Is CircuitPython support available for RPi4?

[solemn finch]

soon

see https://www.youtube.com/watch?v=c9SOPgA8I0E for more details

(recorded today)

[late holly]

Thanks @solemn finch - Will check it out

[civic rune]

Good looking out, always appreciate a caveat. This one only has one output

[civic rune]

Very excited for this

[late holly]

@solemn finch - That was certainly hot off the press. All the best in getting this release out soon

[solemn finch]

thanks!

[late holly]

I believe you are planning Zero 2 support initially. Right? My Zero 2 should be arriving shortly

[solemn finch]

yup. I already got most of it working yesterday

[fresh patrol]

Running on the 400 and having that boot to editor is such a cool idea. Feel like the C64 era computing

[heady cedar]

I have pi 3 A+, no monitor or kbd, and need to install them on a university network that approves such devices via MAC addresses and doesn’t use username and password login. So I need to “headlessly” find the MAC address on these Pi’s. I have had some success attaching them to a phone hotspot then using ifconfig to find the MAC address, but some students are reporting probs and my own experience with hotspot has been hit or miss. Is a USB cable like this the best way to get at the MAC address? Hook it up with OS installed on the card, terminal log in then ifconfig? If there is a better way, pls suggest. Thx!

[hard pike]

You should be able to connect over Ethernet to a laptop or a computer and ssh into it

Doesn’t need internet, just a physical connection where an IP address is established. There’s a number of guides on how to do this, let me find one

[civic rune]

No ethernet on the 3 A+

[hard pike]

Well, Ethernet to USB

😆

[civic rune]

Ah yeah

Lol

[hard pike]

https://www.makeuseof.com/tag/directly-connect-raspberry-pi-without-internet/amp/

[hardy plaza]

Another alternative is to set up a test OS image with a static IP address configured in /etc/dhcpcd.conf where you can set an IP address (to one available, obviously), then share an SSH key with the Pi using ssh-copy-id so you get a secure auto-login. Then you can put this SD card into each Pi, boot it up, then auto-log into it from a desktop and get its MAC address via ifconfig.

[hard pike]

Another great option

[heady cedar]

Thanks all for the ideas. @hard pike I’ll get an Ethernet cable and two usb to Ethernet adapters and give this a try. This seems like it’ll do the trick and I should have the skills for this. Still pretty new to the Pi.

[hard pike]

Definitely! And if that doesn’t work, the suggestion from @hardy plaza is a great option too

Probably still need the Ethernet and usb to Ethernet adapters but it might be faster 🙂

[hardy plaza]

That's basically what I do to register the MAC address of a new Raspberry Pi onto my home router. And certainly, I do have both Raspberry Pi 3 A+ and Pi Zero W's, neither which have an Ethernet connector on them.

[pliant pebble]

Very hyped for RPI Bullseye

yay

[plush wave]

hi there i'm trying to do a keyboard setup on the pico, i've used a few different codes and they give me the same answer ( it wont work ) im only try 2 pins at the moment to get it working but im not sure what im doing wrong. plus no LED is flashing after ive draged the file over.

[plush wave]

Is there anyone on here that can help please

[turbid rivet]

Do you have code or a link to a guide you followed?

[plush wave]

yes down to the letter

[turbid rivet]

Can you share it?

[plush wave]

never mind all sorted but thanks anyway

[civic rune]

I notice that the guide adafruit has for running code on startup on a pi says "This section uses a BeagleBone Black Rev C, running a Debian Wheezy release from July 2015." Could I be having trouble making this work because I'm using raspbian?

also is there a way to find only user created services? I made one last week but can't remember the name

and does my main python code that I want to run on start need to have #!/usr/bin/python at the top?

[agile depot]

Is it possible to manage/edit files on-board with the Raspberry Pi Pico? I’m trying to port some file decompression code to the RP2040, and I don’t know if it’s possible.

[lost wolf]

Yes. Depending on what language you're using. CircuitPython for example, presents as a USB drive called CIRCUITPY on which you can edit files directly. Arduino on the other hand handles that for you, and doesn't present as a drive. The bootloader also presents as a drive regardless of language.

[agile depot]

So I can make some circuitpython code to decompress the file and save it on the on-board drive?

[lost wolf]

I'm not sure I understand what you mean by "code to decompress the file". Can you please try to explain?

[agile depot]

I have a compressed file that I saved to the pico, and I want to decompress it using some python code I found on GitHub. If I make some adjustments so the code works on the pico, could I run the file decompressor on the pico and have it save to the same location?

I wouldn’t be using any SD cards or external storage, I’m using the built in storage on the Pico

[lost wolf]

I think that should be possible. CircuitPython tries to be as Python-compatible as possible, but since it's running on a tiny microcontroller instead of your computer, there are features that we couldn't include due to size. So there's a distinct chance your current code might not run without some changes (and maybe not at all, if it's using a feature we couldn't include). But to run CircuitPython code, you create a file called code.py on the CIRCUITPY drive, and it will run automatically. Give a try!

[agile depot]

Will do, thanks

[scarlet zenith]

installing packages to my pi :)

[turbid rivet]

Taken from https://learn.adafruit.com/circuitpython-essentials/circuitpython-storage:

"""CircuitPython Essentials Storage logging example"""
import time
import board
import digitalio
import microcontroller

# For most CircuitPython boards:
led = digitalio.DigitalInOut(board.LED)
# For QT Py M0:
# led = digitalio.DigitalInOut(board.SCK)
led.switch_to_output()

try:
    with open("/temperature.txt", "a") as fp:
        while True:
            temp = microcontroller.cpu.temperature
            # do the C-to-F conversion here if you would like
            fp.write('{0:f}\n'.format(temp))
            fp.flush()
            led.value = not led.value
            time.sleep(1)
except OSError as e:  # Typically when the filesystem isn't writeable...
    delay = 0.5  # ...blink the LED every half second.
    if e.args[0] == 28:  # If the file system is full...
        delay = 0.25  # ...blink the LED faster!
    while True:
        led.value = not led.value
        time.sleep(delay)

There are file-writing capabilities that are basically the same as that of regular python. Give it a shot!

[lost wolf]

Thanks @turbid rivet!

[agile depot]

I tried running the code last night without changes, only difference being the main python file was renamed to code.py. Does it use serial commands the same way as the command line on a PC?

It gave me some weird error that I can’t remember so I’ll check again soon

[scarlet zenith]

mu has failed

[lost wolf]

Yes! You can use screen or tio to connect to it. Depending on your OS, you have to find the COM port, or it's in /dev/tty.* on Mac and sort of the same on Linux.

Also there's Mu editor that has the serial console built in.

[scarlet zenith]

talking to me? :P

[lost wolf]

Nope 🙂

[scarlet zenith]

Ah ok

Well, I tried to install it and now it looks like it failed :( 'mu-editor' gives syntax error

[lost wolf]

This guide has info on the serial console - check under "Advanced Setup" for using screen, or putty. https://learn.adafruit.com/welcome-to-circuitpython

[scarlet zenith]

I just wanna see what the output of my pico is xD

[agile depot]

Oh ok, I was Ctrl+C and typing directly into the console in Mu

[lost wolf]

That also works.

[lost wolf]

I have no idea what has been tried so far - have you tried the "advanced" way to connect to the serial console?

[scarlet zenith]

Via MU? Well, Mu isn't even opening

[lost wolf]

No, I mean via a terminal program separate from the editor.

[scarlet zenith]

?

[lost wolf]

What OS are you on?

[scarlet zenith]

uh- linux

[lost wolf]

Ok, so there's a terminal program built into it somewhere. That gives you access to the command line.

This page explains the process to use a terminal program to connect to the serial console https://learn.adafruit.com/welcome-to-circuitpython/advanced-serial-console-on-linux

Basically you'll be doing what Mu does in the background.

I'm not sure why Mu isn't working for you

[agile depot]

I ran into a problem, the code I got uses a few modules that don't exist on the Pico as far as I know.

import argparse
import csv
import os
import re
import sys
import traceback

Not sure what to do, is there a code library for these?

[scarlet zenith]

YAY THANK YOU

[hardy plaza]

https://github.com/micropython/micropython-lib/tree/master/python-stdlib

[civic rune]

my pi started not responding and only shows the desktop but with no icons. I right clicked and hit restart and nothing happened, can I just pull the plug?

[lost wolf]

That's what I would do next, but there's always the chance of filesystem corruption, I suppose.

[civic rune]

shoot

[lost wolf]

But sometimes it's the only option.

[pliant pebble]

Yes, I would

[hardy plaza]

You do risk filesystem corruption, so what I'd do in the future (and I even do this on my desktop Linux computers) is enable ssh, so that when the desktop locks up you can ssh in remotely and reboot.

[agile depot]

What does this do? I see it has argparse but some other things like csv and sys arent there

[pliant pebble]

That's happened to me a few times, and I just pulled the plug, and I didn't corrupt my FS - not saying you should, but....

[hardy plaza]

I have a pesky Ubuntu desktop install whose graphics card now and then locks up in Firefox (ugh) so I have to ssh in now and then. If you pull the plug on a Linux OS you risk filesystem corruption. If it didn't happen you were lucky, that's all.

[civic rune]

anyone know what htis means?

ah I got to ca command prompt with CTRL C but then it started again

how can I force shutdown from here?

[pliant pebble]

I agree

[pliant pebble]

sudo shutdown -r now

[civic rune]

it's printing messages too fast for me to type in that command

[pliant pebble]

IDK then

What message is it spewing

?

[civic rune]

the messages in my pic above

idk what they mean

[pliant pebble]

It looks like your FS crashed - but I can't read it that well

[civic rune]

CTRL C/ CTRL D doesn't work

unplug then?

[pliant pebble]

I would

[hardy plaza]

Those are MicroPython ports of the CPython code, an ever-expanding list. You install them on your MCU. I'm currently using about five of them, including asyncio. sys won't be there but its functionality is supplied by other libraries like machine. csv will be supplied by an external library or not at all, may be a work in progress. Not everything has been or ever will be ported as it's a volunteer effort and things get prioritised by what the volunteers want (i.e., you could contribute csv).

[civic rune]

dang, won't boot now

I guess I have to reinstall the OS

[pliant pebble]

Oh, shoot

[hardy plaza]

Your ext4 filesystem is what's called journaling, which means that it keeps a journal of changes that are meant to be applied in the future to update the actual stored filesystem from the changes that are meant to happen. If you restart in the middle of things due to a crash the filesystem attempts to apply the journal to catch up. If successful it recovers, if it fails you have a corrupted filesystem.

[pliant pebble]

Did you have backups? I always backup my OS every week

[civic rune]

I do

[pliant pebble]

Good

I guess it's a good time to install Bullseye 😉

[civic rune]

my SD card is showing 0.0 GB available

[pliant pebble]

formatting

XD

[scarlet zenith]

ok, now there's no module named 'machine'

oh wait

wrong python thing :)

[agile depot]

I tried running the code i found without any editing to see what errors it would give me but the error i got isnt very helpful:

Traceback (most recent call last):
  File "<stdin>", line 1
SyntaxError: invalid syntax

I dont see a file called "<stdin>"

[pliant pebble]

I'm guessing it's in a library

[civic rune]

What do you mean?

[lost wolf]

The ... partition is I think the word I'm looking for... the partition was damaged, most likely.

[pliant pebble]

Balena Etcher is useful for formatting and re-imaging the card

[civic rune]

ah ok

[lost wolf]

What g3holliday said.

There's also the SD Formatter from SD, I think, if Etcher has issues with it. Then you can use Etcher to image it once it's formatted.

[pliant pebble]

If you're on Mac - Disk Utility is a good formatting tool (if you don't want to install anything)

SD formatter is much better though

[civic rune]

ok so I need to reformat the drive? I'm using a spare now

[lost wolf]

Format the SD card, yes.

Super fresh.

[pliant pebble]

Yes, and preferably install a backup, or if you didn't have anything important on the drive, install Bullseye

[civic rune]

I'm working on figuring out a way to get the image into a file so I can just reload a working image

[lost wolf]

What OS are you using?

There are cloning apps that do that.

[civic rune]

windows on my PC, default raspbian for the pi

[lost wolf]

PC was what I meant. I don't use Windows enough to be helpful with app names.

[civic rune]

no worries

I have an iPad but I doubt iPadOS is set up to do this

I'm failing to convince my work to buy me a computer, I'm just using my personal laptop rn

[lost wolf]

But I imagine something exists, there's one for Mac called Carbon Copy Cloner (which might also be available for Windows?), that can copy to and from disk images really easily.

[civic rune]

hmm maybe I know someone with a mac I can borrow if I can't find a windows utility

[lost wolf]

Not sure it's available for free though. But I bet something is.

[civic rune]

eh, if it's under 50 dollars I can probably get them to pay for it

[pliant pebble]

Same

[lost wolf]

Looks like most of the options I could find quickly are under 50.

CCC is not available for Windows though.

[pliant pebble]

Most software I look at is under 50

I don't have the budget for most stuff over 50

[civic rune]

Should I use sudo pip3 to install the adafruit 74hc595 library?

[pliant pebble]

Yes

I think so

If you want it installed system-wide

If not, just pip3

[civic rune]

ok let me look up how to make python3 my default python too

[pliant pebble]

Yeah

[opaque wagon]

win32diskimager is a good one for writing and reading disk images (on windows obv)

[civic rune]

ok, so I first need to find a way to write the disk image from the pi to a USB stick, right?

[opaque wagon]

no, you can write the disk image to a file
like get iso of disk 🙂

[civic rune]

Huh, what would I google?

Doesn't the disk image take up a lot of space?

like the exact amount of space on the pis SD card?

[civic rune]

Trying to understand this code from this guide (https://www.tomshardware.com/how-to/back-up-raspberry-pi-as-disk-image ) sudo dd if=/dev/mmcblk0 of=[mount point]/myimg.img bs=1M What does this do? Trying to understand and not just copy/paste stuff too much

[steady rose]

copies /dev/mmcblk0 to [mount point]/myimg.img

if = in file (file to read from)
of = out file (file to write to)
bs = how many bytes to read/write at a time
sudo = because dd needs to run with elevated privs

[civic rune]

sooooo ok thank you! That makes sense. I should have just looked up bash commands

[opaque wagon]

yes it will though, but you can zip compress it which can help

[civic rune]

is that what pishrink.sh does here?

gahh having a hard time typing this out because discord keeps putting my text into code blocks when I use `

one sec let me fiddle

what is the difference between sda and `-sda1? same with sdb and `-sdb1

[umbral sable]

The punctuation is actually trying to draw an ASCII line. It's showing that the partition sda1 is part of (underneath) the drive sda.

[civic rune]

huh

what does underneath mean in this context?

[umbral sable]

Like a business org chart... it's a piece of a bigger thing, so it's shown as indented.

[civic rune]

huh ok, not getting it but I'll see what I can google

[umbral sable]

Think of like a book table of contents. Chapter 1, section 1-1, etc.

[civic rune]

huh, so why are they both listed as 232.9GB for sdb?

I have 2 flashdrives plugged in

[umbral sable]

That indicates the partition spans the whole drive.

[civic rune]

ahhhhh ok that clicked

so if I partitioned my 256 (232.9 irl) drive it would show up as two diff values?

[umbral sable]

Yep, just like mmcblk0 below, which has two partitions.

[civic rune]

ahhh nice

so this sudo dd if=/dev/mmcblk0 of=[mount point]/myimg.img bs=1M becomes:
sudo dd if=/dev/mmcblk0 of=/media/pi/24B655B9B6558BE4/myimg.img bs=1M?

[umbral sable]

Yes, that would image your internal flash to an image file on the 256G flash drive.

[civic rune]

and do I not need to worry about -mmcblk0p1 and -mmcblk0p2?

I see that the code only calls up -mmcblk0

[umbral sable]

Imaging the disk as a whole will include all partitions on it.

[civic rune]

ahhhh ok

that makes sense. Thanks as always.

how can I change the name of the drive from 24B655B9B6558BE4 to something more readable?

[umbral sable]

It's a little involved, but the short answer is the mlabel command. https://help.ubuntu.com/community/RenameUSBDrive

[civic rune]

hmm maybe I don't need to rename it. I'm literally just using this drive to get the image onto my main PC to backup on github. I haven't figured out how to get to my repo from the pi

weird, when I tried properties -> rename it gave me a permissions error, why would that be?

[lost wolf]

Because you had to sudo create it in the first place? So you need to sudo to rename it? (Guessing here.)

[civic rune]

hmm

but I didn't use sudo on the drive in the past

[lost wolf]

It was a stretching guess on my part.

[civic rune]

no worries, thanks for chiming in 🙂

[civic rune]

I have a fresh pi so I'm going to start again, but could this be an issue?

and do I need #!/usr/bin/python at the top of my python script?

[steady rose]

the guide is a little dated in terms of the mention of BBB and wheezy. but the generic systemd example should still work ok.

you need the shebang if you want to run the .py file as a command, like:

pi:~ $ foo.py

vs explicitly running it with python, like:

pi: ~ $ python3 foo.py

and i think this is the more preferred shebang?

#!/usr/bin/env python 

or maybe even with python3

[civic rune]

ah ok, so in this case I want the shebang right?
Here's what my service file looks like:

[Unit]
Description=12 Days Code

[Service]
ExecStart=/home/pi/Desktop/12days2.py
StandardOutput=null

[Install]
WantedBy=multi-user.target
Alias=12days.service

My file in nano is called 12days.service, I want that to match my Alias, right?

[steady rose]

yes

[civic rune]

ok cool, let me finish the guide and give this a shot!

[steady rose]

12days2.py should have the shebang line and also be chmod +x

[civic rune]

I did both!

So chmod +x makes it so the system can call the code?

[steady rose]

makes it executable

[civic rune]

also in nano, do I use ^O to save the file?

[steady rose]

i think so

or ctrl-x to exit and say yes at prompt

[civic rune]

ok cool thanks

when I ran sudo systemctl enable 12days.service I got:

Created symlink /etc/systemd/system/12days.service ??? /lib/systemd/system/12days.service
Created symlink /etc/systemd/system/multi-user.target.wants/12days.service ??? /lib/systemd/system/12days.service

Anything seem wonky?

[steady rose]

looks ok

[civic rune]

are the ?s just for spacing?

or do the mean something?

[steady rose]

not sure

[civic rune]

ok no worries I'll just assume they are normal

[steady rose]

it didn't gripe though. no obvious errors.

[civic rune]

time to reboot?

seems like it

[steady rose]

you can just enable without reboot

sudo systemctl status 12days.service

to check current state

sudo systemctl start 12days.service

to start

and can then run the status command again

[civic rune]

hm ok when I ran sudo systemctl status 12days.service I got:

??? 12days.service - Twelve Days of Christmas Code
  Loaded: loaded (/lib//systemd/system/12days.service; enabled; vendor preset: enabled
  Active: inactive (dead)
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~

does the Active: inactive (dead) mean anything?

[steady rose]

try starting it and running status again

[lost wolf]

Such a clear message 😄

[civic rune]

at the bottom there's a message saying:
lines 1-3/3 (END) but I can't get out of this dialog menu/area

[opaque wagon]

ctrl + c usually does it (i forgot what it was lol)

or ctrl + q??

[civic rune]

ctrl c worked

[civic rune]

nothing happened when I ran this code

[steady rose]

that's normal

run status again

[civic rune]

ok status gave me a bunch of errors, too many to type out, let me take a picture

I'd get on discord on the pi but it reallllly struggles there

Not sure how visible this is. Lmk if I should take two close shots

a syntax error it seems like?

let me open it in nano again

would that be sudo nano /lib/systemd/system/12days.service?

[steady rose]

what happens if you try to run the file directly?

/home/pi/Desktop/12days2.py

[civic rune]

I just ran it from Thonny and it ran fine

let me try from the cmd line see if anything happens differently

would that be python /home/pi/Desktop/12days2.py?

[steady rose]

not from thonny

from command line

pi:~ $ /home/pi/Desktop/12days2.py

basic idea is to manually do same thing the systemd service is try to do

which is the ExecStart line in the file

[civic rune]

got a bunch of errors like import: command not found as well as a syntax error

ahhh I forgot the shebang

[steady rose]

it worked in thonny because that's different. doesn't need a shebang, etc.

[civic rune]

ah ok

so the shebang line should be what again?

ah i got it

[steady rose]

what do you get from which python3?

[civic rune]

one sec

/usr/bin/python3

[steady rose]

make shebang that with #! added in front

#!/usr/bin/python3

[civic rune]

heyyyy

it's working!

now how can I stop the code from running from the command line?

[steady rose]

same as start, but with stop

[civic rune]

ahhhh

that's so neat!

thanks everyone

[opaque wagon]

systemd is very very nice :)

much better then the old methods

[civic rune]

yeah this is pretty neat

let me try rebooting and see if it starts on startup like it's supposed to

[steady rose]

yep. good next test.

[civic rune]

so I'll need to go into the cmd line and run sudo systemctl stop 12days.service if I don't want the code to be running?

[opaque wagon]

yes

[civic rune]

noiice

[opaque wagon]

but if you want it to stop starting on boot, use the disable command i think

(enable to well, enable)

[steady rose]

yah...i think so too. that's what the disable/enable step is about. so don't need to delete the service file or anything.

can toggle boot behavior that way

[civic rune]

also if you really don't like christmas music, don't take a job that requires you to listen to it on repeat while debugging. Just a free pro tip

[opaque wagon]

just make sure it's not all i want for christmas is you

[civic rune]

I would refuse to work on that also we can't afford the licensing

[opaque wagon]

haha

[opaque wagon]

btw you also don't need the .service part at the end of the service name - systemd will find it (saves typing but i'm pretty sure the tab autocomplete will put it in so either way)

[civic rune]

oh weird. the song "hung" while playing for a second. Randomness from pygame?

[opaque wagon]

randomness most likely - maybe the cpu load spiked

or disk stuff

[civic rune]

ok let's hope

[opaque wagon]

any exceptions?

[civic rune]

I'm running it on boot so it's not printing exceptions anywhere

[opaque wagon]

actually if it crashes systemd would save it (systemd saves the like last 10 lines of output from your program) but your service file redirects stdout to null

[civic rune]

how can I change that? and is that /dev/null?

[opaque wagon]

i thinik so
(as you can tell i don't really know what i'm doing)
remove the StandardOut = null line from your service file and do a daemon-reload and sudo systemctl restart 12days

[civic rune]

will just straight removing it cause exceptions to go to the normal place?

[opaque wagon]

no (if you mean normal place = console)

but systemd saves a bit of program output so if it ever crashes you can see it with status command

[civic rune]

ah ok

I'll do a reboot again and see if it happens again. If it was just once I can live with it

[opaque wagon]

idk if you want this but you can also get it to restart if it crashes: (add to [Service] section of service file)

Restart=on-failure
RestartSec=10

(got from https://www.howtogeek.com/687970/how-to-run-a-linux-program-at-startup-with-systemd/)

[civic rune]

I'd rather it not try again I think, idk why though

ok time to write up what I've learned so I don't lose this progress

[opaque wagon]

🙂 also if it works i would do backup of code + service file at least

so you don't have to rewrite everything again

[civic rune]

yeah my next step is a backup of a working image, put on github

I'm actually employed in part because there were no backups of htis system, so I had to start from scratch

Good learning experience but a tad annoying

how can I create just a basic text file on the pi? Do I have to use nano?

[opaque wagon]

for an empty file you can do touch <filepath>

for one line of text you can do echo "the one line text" > filepath

note that the echo and > will overwrite the file if it exists

[civic rune]

one sec, gotta step off and complete open enrollment stuff. Gotta make my sister my beneficiary for life insurance. My dog doesn't have a SSN unfortunately

hm, our insurance isn't that bad. 30/300/50%

that's kinda #general-chat sorry

[civic rune]

how do I use nano to open my service to edit it?

figured out opening it, when saving it do I just write out and use the same filename to overwrite?

[lost wolf]

Ctrl+x, y I think.

Yeah basically.

It's kind of confusing.

[civic rune]

hmm write out is CTRL-O

I'll just try it

[lost wolf]

Oh. Fair enough. I do CTRL+X, and then hit y when it asks if I want to save and overwrite or whatever it asks.

Kind of like there are multiple ways to save in vim.

I'm sure.

[civic rune]

write_out didn't work let me try your way

[lost wolf]

Stern warning if you say "no" you'll lose your work, iirc.

I don't use it that often... only when I need to quick edit something and am afraid I'll screw it up in vim. Because I'm kinda bad at vim.

[civic rune]

it's asking me to write a filename, use the same one I assume?

dang, it doesn't seem to have made the changes

[steady rose]

try with sudo

if you don't have permissions, it's probably opening it read only.

[civic rune]

I did use sudo

[opaque wagon]

if you mean no changes to the service, then you need to do sudo systemctl daemon-reload

[civic rune]

hmmm

let me re do the changes and try that

didn't seem to do the trick but let me try again

[nova karma]

is anyone else getting errors imaging raspberry pi os bullseye 64bit? My download's image checks out, but I keep getting failed checks after writing. tried different sdmicro's and different usb adaptors

using balenaEtcher on windows, imaged pi OS success fully bunches of times before

and an ubuntu server image just flashed fine. I wonder if something in the image didn't get updated so that etcher can verify properly

[elder palm]

anyone else having issues with their raspberry pi 400 and the hyperpixel 4 non-touch staying blank

the only thing i can find is something to do with some diode on pin 12.

[civic rune]

I got some feedback that using /lib/systemd/system is "wrong" and that /etc/systemd/system is better. Anyone have an opinion?

[opaque wagon]

Every guide I remember reading used /etc - never seen /lib used for systemd

[civic rune]

Yeah the adafruit guide uses /lib it seems

[heady cedar]

Is there a way to use raspi-config or some other tool to add another network? I can get set up on multiple networks if I use a file like the enclosed screenshot in what-supplicant at setup. Is my best bet returning the card to a card reader, adding this file again, then rebooting the pi with this new file? Trying to figure out easiest procedure to coach students through. Thanks!

[plush wave]

Morning all, slight problem I've used a code from a YouTube video it says there is a problem with the digitalio line any ideas

Using a pi pico

[plush wave]

back on the cpu, here is the error message

%cd 'E:'

%Run code.py
Traceback (most recent call last):
File "E:\code.py", line 2, in <module>
import digitalio
ModuleNotFoundError: No module named 'digitalio'

i thought i fixed it yesterday but i was wrong

[ruby night]

@plush wave It looks like you are trying to tun the code.py on your host computer, not on the pico. Have you installed CircuitPython on the Pico?If you want to see the code run on the pico, you have to open a terminal session to have access to the REPL. This guide may help you get started https://learn.adafruit.com/welcome-to-circuitpython

[plush wave]

Circuitpython is installed

[ruby night]

how are you connecting to the Pico?

[ruby night]

the wpa_supplicant.conf file is stored on the Pi in /etc/wpa_supplicant/wpa_supplicant.conf You can edit it there and save it. It does require editing as 'sudo' since it is owned by 'root'

@plush wave I don't understand what this is doing ```%cd 'E:'

%Run code.py
Traceback (most recent call last):
File "E:\code.py", line 2, in <module>
import digitalio
ModuleNotFoundError: No module named 'digitalio'

Or maybe I am misunderstanding what you are doing. Have you used CircuitPython before?

[plush wave]

Not really, learning the basics of keyboard command with switch, thought the video would he a good place to start

I duplicated the code letter by letter and got this

Error

[ruby night]

How are you connecting to the Pico?

[plush wave]

Via USB to laptop

[ruby night]

I meant are you creating a terminal session via the Mu editor or something like Putty --- or are you just going to the E: drive and trying to execute the code.?

[plush wave]

I'm using thorny to code

[ruby night]

ah -- OK -- make sure you are executing the code on the Pico and not on your computer.

[plush wave]

I did that clicked save then run the program unless I'm missing a step

[ruby night]

in the terminal window can you type 'help('modules')` ? What does it show?

And you have CircuitPython installed, not MicroPython? correct?

[plush wave]

Give me a min just reloading the laptop bloody updates

And yes it's installed

[ruby night]

what is -- Micropyhton or CircuitPython? -- how did you install it?

[plush wave]

Download, copy and paste onto the board then it reloaded it self

[ruby night]

What file did you download and install?

[plush wave]

Give me 1 min need the laptop up. Its what I found on YouTube, and called adafruit circuitpython hid

[ruby night]

When you can, post a link to the video. as well as the name of the file you installed.

[plush wave]

heres the video

https://www.youtube.com/watch?v=aEWptdD32iA&t=77s

[ruby night]

OK -- it mentions the adafruit circuitpython hid being "pre-installed" how did you install it? Where did you get it?

[plush wave]

https://github.com/adafruit/Adafruit_CircuitPython_HID

[ruby night]

That is a library -- I am confused about what is installed on your Pico -- Can you post a screenshot of what you see in Thonny when you start up?

What version of CircuitPython did you install? how did you install it?

If you can post a screen shot of running the help('modules') that would help...

I'm afraid I have to go away -- I hope someone else can help... I suspect you do not actually have CircuitPython installed but I need more information to confirm that.

this video from novaspirittech may help https://www.youtube.com/watch?v=onBkPkaqDnk. He shows how to install CircuitPython as well as the library. This guide from adafruit is also a good place to start.https://learn.adafruit.com/getting-started-with-raspberry-pi-pico-circuitpython/overview

[plush wave]

i think i've missed a step just need 10 mins to go through it all over again

[ruby night]

Good luck -- I'll be away for the next hour or so.

[plush wave]

found the issue i think CircuitPython 7.0.0 is not loading in correctly. i download it of the website open up the zip file copy and paste the file on to the pico then when i open thonny its not seeing it

CircuitPython 7.0.0 is not working at allm i have the error notice but is bloody big

never mind forgot to select interperter i had it on microphton, next stage

[turbid rivet]

@faint sparrow If you're looking for a USB to WiFi, you might be better off with one something like this: https://www.amazon.com/TP-Link-wireless-network-Adapter-SoftAP/dp/B008IFXQFU/

[plush wave]

all working now bud, thanks for your help

[ruby night]

Congratulations! Have fun with it!

[heady cedar]

Any recommendations for migrating students who have been using Mu cod microcontroller CircuitPython to Raspberry Pi code editing? We’ve been just pasting into Nano when sshing in. No way to Mu on the Pi is there? Does Thomy work with CircuitPython on the Pi?

[tired marsh]

is it only a headless setup ? If not, you can pip install Mu on a Pi.

Unless I'm mistaken, it should work.

[heady cedar]

It is headless. They use terminal to ssh in & vnc isn't tough to setup. Can you Mu on the Pi over VNC & use CircuitPython? It would be slow, bur I could give this a try.

Very new to Pi, so these are newbie questions, but am trying to run the script at: https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/installing-circuitpython-on-raspberry-pi

sudo pip3 install --upgrade adafruit-python-shell
wget https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/raspi-blinka.py
sudo python3 raspi-blinka.py```
Output is this:
```Updating System Packages
Blinka Hit:1 http://archive.raspberrypi.org/debian bullseye InRelease
Blinka Hit:2 http://raspbian.raspberrypi.org/raspbian bullseye InRelease
Blinka Reading package lists...
Upgrading packages...
Blinka E: Broken packages

Blinka Reading package lists...
Blinka Building dependency tree...
Blinka Reading state information...
Blinka Calculating upgrade...
Blinka Some packages could not be installed. This may mean that you have
Blinka requested an impossible situation or if you are using the unstable
Blinka distribution that some required packages have not yet been created
Blinka or been moved out of Incoming.
Blinka The following information may help to resolve the situation:
Blinka 
Blinka The following packages have unmet dependencies:
Blinka vlc-bin : Depends: libvlc-bin (= 3.0.16-1+rpi1+rpt1) but 3.0.16-1+rpi1+rpt2 is to be installed
Blinka vlc-plugin-skins2 : Depends: vlc-plugin-qt (= 3.0.16-1+rpi1+rpt2) but 3.0.16-1+rpi1+rpt1 is to be installed
Blinka Exiting due to error: Apt failed to install software!```
Unsure what "is to be installed" means. Can I do anything to correct this & does it impact the installation of Blinka/CP on this device? Thanks!

I'm using the latest Bullseye. Just downloaded & installed yesterday.

Solution found (in case anyone runs into this). I opened the VNC desktop, ran the upgrade from the upper-right pulldown, the VNC issues seemed to go away. I could then rerun the blinka script. Just ran blinkatest & it seems to work.

[heady cedar]

Transferring files between the Mac & Pi is super-easy with Netatalk. I can also connect to the Pi as an external volume via the finder, so I can save Mu files to my Pi. Console doesn't work for execution, but I can run code in ssh so at least we get a familiar editor. Is there a similar tool for windows? Is WinSCP what most folks use for transferring fileis from Win to the Pi?

[tired marsh]

you can run windows file sharing on the pi too

I tend to prefer using SSH (SFTP) with Cyberduck (on mac, it's also on windows), it's free and lets you open the files in any app and uploads the changes, but it doesn't work right with Mu

[heady cedar]

@tired marsh thanks. So nothing special needs to be used to access the Pi on Windows as long as they're on the same network? It'll appear in a sort of Network icon? (On the Mac there's a network icon one clicks & the network volumes show up - after netatalk is installed, the Pi is there). Appreciate your kind help - this is really useful to me!

[tired marsh]

you would have to install Samba on the pi to get the windows file sharing

[wanton holly]

if i run a raspi 3B+ headless , how much more compute power can i have ?

[steady rose]

relative to what?

[faint sparrow]

Ok, thx 👍

I was wrong I didn't meant USB to Ethernet, I mean GPIO to Ethernet because I've an Ethernet switch connected to a CPL Kit right under my monitors

[turbid rivet]

Ahhh, so you're looking for an Ethernet HAT of some sort. Adafruit used to carry one, but it's since been discontinued. Waveshare has a nice Ethernet / USB Hub HAT that might be a good fit? https://www.amazon.com/Ethernet-USB-HUB-HAT-Compatible/dp/B07T16RSFM

[faint sparrow]

Yea

Thx

[agile depot]

Could the RP2040 technically emulate the Pico-8 computer on a 128x128 display? I’m working on a Lua to Python translater and I don’t know if it can refresh sprites and tiles fast enough

The specs of the computer can be found here: https://pico-8.fandom.com/wiki/Pico8

[solar meteor]

I've got mosquitto running as a MQTT broker on my Pi. Is there a way to see all past topics?

[clever venture]

Hello everyone I need help setting up my PMSA0031 adafruit AQI sensor in raspberry pi 4

[civic rune]

What issues are you encountering?

[clever venture]

I'm trying to use the code that's providing by the adafruit website in pythong, but I get errors

let me know if you want to check the error and the code screenshot

[civic rune]

Yeah you can directly upload your code as well as paste the full exception trace. That's usually what folks ask for around here. Can't guarantee I can fix it but it'll help others who can help

[clever venture]

should upload it here

?

[civic rune]

Yup! If it's not proprietary

[clever venture]

sure I will upload the pinout and also the code

[civic rune]

your red wire is tied to ground, not 5V. Make absolutely sure that you need 5V and not 3.3V

(it looks like your red wire is tied to ground rather, not 100% sure)

[clever venture]

Oh yeah I accidently did that a minute ago

[civic rune]

that's a fun sensor, I have one lying around. It's really easy to work it ime

[clever venture]

thank you

I have a project demonstration next Monday and I'm struggling with this

[civic rune]

what errors are you getting?

[clever venture]

let me send you the code first

it doesn't recognize "import board", import busio" all of them from line 1 through line 5

[civic rune]

ahh did you install blinka?

https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/installing-circuitpython-on-raspberry-pi

[clever venture]

no I didn't

[civic rune]

make sure you do that first, blinka allows you to use modules like board. You'll also need to install the library for the sensor

[lost wolf]

I think installing the sensor lib should install Blinka. As long as the library is setup right.

[civic rune]

ahhh ok

[lost wolf]

I think....

[civic rune]

I assumed they didn't have blinka installed because of the error they got. But you'd be able to tell in the terminal window if it's installing blinka at the same time you install the sensor lib

[lost wolf]

I'm pretty sure you're right they don't have Blinka installed. I was simply letting you know you could, in theory, eliminate one step there.

[civic rune]

ahhh ok thanks! Always looking for efficiencies

[lost wolf]

I say "If it's setup right" because I had to fix a similar issue in a special library earlier today, so I always caveat it with that in case the lib needs an update.

[clever venture]

I just install the blinka and the system is rebooting

is there any library that I have to install as well?

After installing the blinka the previous errors are cleared but now its giving me error for the DigitalIInOut

[lost wolf]

difitialio is misspelled. It should be digitalio. And yes, you need to install the PM25 library.

[clever venture]

Can you please guide me how to install that?

[lost wolf]

pip install adafruit-circuitpython-pm25 I believe. The PM2.5 guide should have the rest of the instructions if there are any: https://learn.adafruit.com/pmsa003i/python-circuitpython#python-installation-of-pm25-library-3067526-7

[clever venture]

Thank you so much guys

[civic rune]

Might need pip3

[lost wolf]

Ah good call. Yep. I am not good at thinking about that because my setup doesn't need it.

[civic rune]

Yeah I always change Python to Python3 first thing so I don't have to worry about it. I literally never need Python 2

Unless I want to write some insecure banking software used by millions. Looking at you, major banks

[clever venture]

I used pip3

the code says "Unable to find the PM2.5 device"

[steady rose]

are these pins soldered?

wiring on pi side is also odd. not sure if you're trying something different?
https://learn.adafruit.com/pmsa003i/python-circuitpython#python-computer-wiring-3067520-4

[clever venture]

still get the same error

cool! its working

[clever venture]

thank you

@lost wolf @civic rune @steady rose you guys are awesome. Thank you so much

[lost wolf]

You're welcome! Glad you got it sorted out!

[civic rune]

Yay! Glad any time I can be of assistance. I have a lot of paying it forward to do :)

[civic rune]

Woooooo

[clever venture]

We have a project demonstration on Monday

[civic rune]

Sounds like you made good progress! This is for school?

You picked a nice sensor

[clever venture]

Yeah, I was so stressed about that, but I’m really glad we got this done today

[civic rune]

One tweak I might add is changing
Particles > 0.3 um... to
Particles -> 0.3 um... or even
Particles - 0.3 um...

The current way sort of reads as "Particles greater than ..."

[late holly]

The cable I got as an accessory for the Pi Zero WH allows me to connect one USB peripheral such as USB keyboard. What adaptor do I need to connect both USB keyboard and USB mouse?

[civic rune]

Which cable did you get?

Ah I see the one adafruit sells.

Hm I'd get a USB expander dongle. Pretty inexpensive

[late holly]

Thanks @civic rune - Can you share a link to the USB expander dongle?

[civic rune]

Sure it's not an adafruit product, I just got mine at best buy

https://www.bestbuy.com/site/insignia-4-port-usb-3-0-hub-black/4333600.p?skuId=4333600&ref=212&loc=1&gclid=CjwKCAiAm7OMBhAQEiwArvGi3MZTcOMtlUJjhHPCuj9vAODM7uIGDFRAaegcCKK5evrr2MHT-p6_BBoC2t4QAvD_BwE is the one I have

[tired marsh]

any USB hub

I found a tiny 2 ports hub with a short cable, let me see if I can find it

[late holly]

Thanks @civic rune

[tired marsh]

oh of course the entry doesn't exist anymore on amazon

[civic rune]

Any time!

[late holly]

Thanks @tired marsh for checking

[heady cedar]

Yesterday I posted that I ran into the problem below using a fresh Bullseye install on a Pi 3A+:
https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/installing-circuitpython-on-raspberry-pi
I could get around this by VNCing into the Pi and select the "upgrade" icon from the desktop. If folks haven't installed VNC yet, is there a work-around to perform any upgrade? I did an apt-get update & upgrade as indicated in the docs before installing this. Are there any additional gotchas in using Blink with Bullseye worth noting? Thanks!

Blinka Reading package lists...
Upgrading packages...
Blinka E: Broken packages

Blinka Reading package lists...
Blinka Building dependency tree...
Blinka Reading state information...
Blinka Calculating upgrade...
Blinka Some packages could not be installed. This may mean that you have
Blinka requested an impossible situation or if you are using the unstable
Blinka distribution that some required packages have not yet been created
Blinka or been moved out of Incoming.
Blinka The following information may help to resolve the situation:
Blinka 
Blinka The following packages have unmet dependencies:
Blinka vlc-bin : Depends: libvlc-bin (= 3.0.16-1+rpi1+rpt1) but 3.0.16-1+rpi1+rpt2 is to be installed
Blinka vlc-plugin-skins2 : Depends: vlc-plugin-qt (= 3.0.16-1+rpi1+rpt2) but 3.0.16-1+rpi1+rpt1 is to be installed
Blinka Exiting due to error: Apt failed to install software!```

[steady rose]

This was the "full" version of RPI OS?

it sounds like apt-get update / upgrade from command line did not fully work? but using some "upgrade" thing from the desktop UI did work?

in general, it looks like some kind of OS update/upgrade thing not working. but once past that, Blinka is working ok?

[heady cedar]

I selected the first upgrade option, the default option, in the Raspberry Pi imager. When accessing the desktop icon to update, yes, this did install Blinka properly. I'm trying to minimize steps (and also learn a few things).
The apt-get upgrade says:

requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 vlc-bin : Depends: libvlc-bin (= 3.0.16-1+rpi1+rpt1) but 3.0.16-1+rpi1+rpt2 is to be installed
 vlc-plugin-skins2 : Depends: vlc-plugin-qt (= 3.0.16-1+rpi1+rpt2) but 3.0.16-1+rpi1+rpt1 is to be installed
E: Broken packages

[humble marsh]

I have done apt-get dist-upgrade (now also called full-upgrade, at least on some distributions) for years, which does a more complete job of upgrading. I am not sure it is applicable here, but it won't hurt.

[steady rose]

i ran through the process, per that linked guide, on a pi zero 2 w using the latest (2021-10-30) lite version and ran into no issues

downloading desktop version now and will try that also

since it's something with vlc, which i doubt is in the lite release

[steady rose]

recreated:

pi@raspberrypi:~ $ sudo apt-get update
Get:1 http://archive.raspberrypi.org/debian bullseye InRelease [23.5 kB]
Get:2 http://raspbian.raspberrypi.org/raspbian bullseye InRelease [15.0 kB]
Get:3 http://raspbian.raspberrypi.org/raspbian bullseye/main armhf Packages [13.2 MB]
Get:4 http://archive.raspberrypi.org/debian bullseye/main armhf Packages [205 kB]
Fetched 13.5 MB in 38s (352 kB/s)                                                                            
Reading package lists... Done
N: Repository 'http://archive.raspberrypi.org/debian bullseye InRelease' changed its 'Suite' value from 'unstable' to 'stable'
pi@raspberrypi:~ $ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 vlc-bin : Depends: libvlc-bin (= 3.0.16-1+rpi1+rpt1) but 3.0.16-1+rpi1+rpt2 is to be installed
 vlc-plugin-skins2 : Depends: vlc-plugin-qt (= 3.0.16-1+rpi1+rpt2) but 3.0.16-1+rpi1+rpt1 is to be installed
E: Broken packages
pi@raspberrypi:~ $

[humble marsh]

does it make any difference if you do dist-upgrade?

[steady rose]

what's a good tag for syntax highlight shell output like above? tried bash,sh, console

@humble marsh that worked

[ruby night]

lately, Ive been using sudo apt update then sudo apt full-upgrade I "think" that is similar to dist-upgrade

https://askubuntu.com/questions/770135/apt-full-upgrade-versus-apt-get-dist-upgrade

[heady cedar]

Yes - sudo apt full-upgrade solved the problem. Thanks so much (my students thank you, too)! Added a sudo apt clean to the end of the instructions.

[steady rose]

@humble marsh ^^ think this is something worth updating guides?

[humble marsh]

yes, definitely

i found that upgrade was often not sufficient. It's supposedly not as "safe", but I've never seen that to be a problem. It seems to cause more problems than it solves.

[steady rose]

it seems like there is some general updating of the whole apt-get vs apt tooling? happening in linux land in general. not pi specific.

[humble marsh]

I think full-upgrade was made a synonym for dist-upgrade just because it's clearer. apt vs apt-get: I discovered a few years ago apt was sufficient, at least on the distros I was using, and I am a lazy typist

and yes, this is on Ubuntu, so def not pi-specific

[steady rose]

just thinking in terms of guides...can update...but if it's an ongoing moving target, then not sure

is apt then new apt-get?

is full-update/dist-upgrade then new upgrade?

etc

[sturdy blade]

Is it possible to use raspberry pi to read a analog co sensor without a adc chip?

[umbral sable]

The short answer is no. The long answer is that there are various circuits which can be made to function as a poor man's ADC.

[sturdy blade]

Okay thanks. I will order a adc then

[runic yoke]

Hi! Is it ok for me to ask for big-picture advice about raspberry pi-based projects here? I'm designing a system that will involve using raspberry pi's, GPIO and an app, and I'm trying to figure out what the best choices are for communication methods and media handling

I know that's pretty generic, but I wanted to see if that's the kind of stuff that's ok to post before diving into the details.

[umbral sable]

Yep, completely fine.

[runic yoke]

Awesome!

I'm designing a system for incorporating buttons and sensors into interactive exhibits. I'm trying to figure out the best way of networking it all. I was thinking that for GPIO buttons, they would be coming off of a raspberry pi zero.

That raspberry pi zero would be issuing mqtt messages in response to GPIO presses.

I want to bundle all of this information in a way that would make it easy for someone (a collaborator) to come in and make a vue.js app that reads and responds to those inputs.

I guess my questions are: do you think using mqtt for communications is a good choice?

My other question is about incorporating into vue.js - not something I'm as familiar with. Any comments on what would be the easiest way to bridge?

I was kind of figuring I would have one raspberry pi that was hosting the mqtt broker, and aggregating all of the mqtt data / messages and then feeding that to the app.

[runic yoke]

is that a mqtt to websockets question?

I'm someone who is probably more into hardware than software, but ive been put in a position where im trying to collaborate with a software person who prefers using vue.js, and I'm trying to figure out a replicable approach. if this is too broad i totally understand.

[young sage]

pico-mp3

[late holly]

@solemn finch - I just got my Zero 2W. Is CircuitPython available somewhere for me to test?

[scarlet zenith]

Hello again! I got remote desktop to work! :D I now have a question- i2c.
(question asked n another channel)

err- I might ask again in circuitpython help, but only the 2nd part since Idk if this is pi specific xD

[humble marsh]

Here's a .img to try, which I tested yesterday successfully. <#circuitpython-dev message> USB does not work. I used balena-etcher to make a card. HDMI out works, and you can talk to the REPL via UART serial. It's very early days yet, but you can play with it.

[scarlet zenith]

Incase anyone else runs into the issue, the i2c lcd's I got with arduino projects are HD44780 backpacks. 16x2. Using a library from github by bablokb I was able to get it working. Idk what the policy is about links to user made libraries-
Using the example i2c lcd from adafruit made the display flash on when ever it was recieving instructions. Wether the instructions where backlight on/off or writing text. So again, if you are using a i2c protocol, and the mcp230xx lib is making it flash, for me it was the wrong backpack type.

[haughty geode]

HyperPixel 4 that was working fine some weeks ago now looks like this: is the hardware just shot, most likely?

[worn oak]

reinstall drivers

I am getting atomic error when running gv_buttontotalk.py
https://learn.adafruit.com/using-google-assistant-on-the-braincraft-hat

[haughty geode]

This particular OS install isn’t more than a day old, drivers got installed just an hour or so ago. You’ve seen something like this before?

[worn oak]

the troublshooting section on the brainhat
https://learn.adafruit.com/adafruit-braincraft-hat-easy-machine-learning-for-raspberry-pi/kernel-module-troubleshooting

your commands to fix it will be different, but it looks like the same symptom

if kernel was upgraded you will need to recompile drivers

[haughty geode]

Not on Bullseye (this is on a Pi Zero, and it needs Chromium/Firefox, which were apparently compiled only for later CPU versions), but will check.

[late holly]

Thanks @humble marsh

[worn oak]

I have been trying for days to get google assistant running on pi3 w/ brainhat and get this error
https://pastebin.com/Ej3TtTeA

[worn oak]

I have the same display, you will need to ssh in and redo steps to install it again '

[heady cedar]

Installed a fresh Bullseye this week, then CircuitPython. Running
python --version
shows: Python 3.9.2
Is it now "safe" to switch over to swapping out any old commands that ran as python3 or pip3 with just python & pip? Thx for advice!

[haughty geode]

Looks like Bullseye is exclusively Python 3 as per https://wiki.debian.org/Python -- if you want to maintain some sort of backwards compatibility with mixed 2/3 distributions, and if python3 and pip3work on Bullseye, can leave them as is. But if you're just targeting Bullseye, then python and pipwould be fine, too.

[heady cedar]

Thanks, @haughty geode I'm going to stick with current distributions in class, so it's good to know I can refer to python & pip without a version after it. May be one less thing for students to remember. Anything to warn students about if they read an old tutorial with python3 or pip3 in it? I've used those on this pi & it seems like they're aliased, so no concerns, but I want to make sure I'm providing correct info. Cheers!

[haughty geode]

I assume the 3-suffixed ones will point to a Python 3.x version for the foreseeable future, so I don't think that's a concern. I'd be more concerned about an old tutorial having other deprecated stuff in it. "I Googled some TensorFlow install instructions" is a common thing at work for me at work, and it almost never goes well for them.

[heady cedar]

Trying to get neopixels to work on a Raspberry Pi 3A+ w/latest Bullseye.
Code is executing (I can see #s in the for loop), but pixels aren't lighting up.
Took the same strip + jumpers to Arduino Nano RP2030 Connect to make sure wires or strip weren't a problem, just added pin-pin jumpers to connect to the Arduino's breadboard from the socket jumpers going into the pin. Also changed the one board pinout number in code (used board.D7 on Arduino). Code worked fine & wiring seems intact, too.
Image below shows how I've wired to my Raspberry Pi. Very simple code follows.
I'm assuming my code needs to refer to the signal pin as board.D12 on the Pi, but I also tried the Pi's GPIO #: for that pin (18), still no luck. Any thoughts on why pixels might not be lighting?
BTW: I first installed blinka, then sudo pip install rpi_ws281x adafruit-circuitpython-neopixel

import board, time, neopixel, digitalio

strip_pin = board.D12
strip_num_of_lights = 30
strip = neopixel.NeoPixel(strip_pin, strip_num_of_lights, brightness=0.4, auto_write=True)
strip.fill((0, 0, 0))
wheel_value = 0

print("I am running!")

for i in range(30):
    strip[i] = (0, 0, 255)
    print(i)
    time.sleep(0.01)
while True:
    pass```

BTW: I apparently need to run my python code with sudo, e.g. sudo python flash_pixels.py. Is that typical or did I mess something up with the install?

[turbid rivet]

Did you try strip.show()?

@heady cedar

[hard pike]

I would suggest two things:

1. Level shifting the data line to 5V with a level shifter

2. Adding a 330 or 470ohm resistor in the data line

[heady cedar]

Thx @turbid rivet Didn't think I needed it if I added auto_write=True to the NeoPixel declaration, but added it afterward & still no help.

[hard pike]

RPi IO are 3.3V and most strips want 5V data lines and a resistor

https://learn.adafruit.com/adafruit-neopixel-uberguide

[heady cedar]

Thx @hard pike. I've seen the advice in Tony D's guide that suggests a level shifter or diode, but folks here & Kattni's tutorial says you should be able to get away without if you're just lighting a few neopixels (or, I'm assuming, if the brightness is low?), but unfortunately this doesn't seem to be working. Even if I only work with 5 lights on the strip & define the strip w/5 lights, I still don't get any output.

[hard pike]

Did you add the data line resistor

I think that is something you need on the data line at a minimum

[heady cedar]

Just tried adding a 440 Ohm resistor between the signal wire on the NeoPixel strip & the jumper headed into GPIO18. No luck. Also - to check: should I be referring to the pin as board.D18 (the GPIO pin #) or board.D12 (the board pin #). I've tried both & neither worked. I see Tony's code shows wiring into the same pins I'm using (https://learn.adafruit.com/neopixels-on-raspberry-pi/raspberry-pi-wiring) and his code on the next page shows: board.D18, so I assume the # after the D is the GPIO number. Is that correct?

[hard pike]

Seems like that would be the case

The only other thing I could think of is you don’t have enough power from the 5V pin to drive the LEDs. Do you have a separate 5V supply you can use?

[solemn finch]

@late holly check out yesterday's deep dive: https://www.youtube.com/watch?v=LkYn9_HwPUE and the chat in #live-broadcast-chat that went with it

[late holly]

Thanks @solemn finch

[heady cedar]

@hard pike I think I just fried my strip using the wrong power supply 😦 Will pick up more from the office later & try again.

[hard pike]

That is my worst fear plugging stuff in

[late holly]

I used

sudo python3 adafruit-pitft.py --display=28r --rotation=90 --install-type=fbcp

with my https://www.adafruit.com/product/1601

My monitor connected to HDMI shows the display in a small part of the screen.

How can I get out of this mode to a full screen display on the monitor?

[civic rune]

I think it's under Preferences under the raspberry button

how can I unlink my service that's running under /lib/systemd/system? I want to move it to /etc/systemd/system

[late holly]

Thanks @civic rune - That helped

[civic rune]

sure thing!

would sudo systemctl disable myservice.service suffice?

[late holly]

I am trying to run the RPLidar as per instructions https://learn.adafruit.com/slamtec-rplidar-on-pi/cpython-on-raspberry-pi using CircuitPython 7.0 and getting the following error. Any suggestions?

[humble marsh]

We fixed the example to include a timeout, which was necessary with new firmware: https://github.com/adafruit/Adafruit_CircuitPython_RPLIDAR/pull/17

See also https://github.com/adafruit/Adafruit_CircuitPython_RPLIDAR/issues/15

[late holly]

Thanks @humble marsh. I will check

@humble marsh I had downloaded the project bundle from https://learn.adafruit.com/slamtec-rplidar-on-pi/cpython-on-raspberry-pi and after unzipping, went to CircuitPython 7.x directory and ran display_lidar_pi.py ..
How do I apply the fix from the github links you point to in order to run the example?

[civic rune]

you can clone the repository and replace the files manually. That's how I'd do it

[humble marsh]

YOu can edit the file with the line lidar = RPLidar(None, PORT_NAME) to be lidar = RPLidar(None, PORT_NAME, timeout=3)

[late holly]

Thanks@humble marsh. It worked

[civic rune]

does the board module on the pi use BCM numbering?

such that this pin would be board.D3?

and does an equivalent exist in board for GPIO.wait_for_edge(gpio_pin_number, GPIO.FALLING)

[tired marsh]

yeah I think so:

>>> board.SCL
3
>>> board.D3
3

[civic rune]

ahh ok nice

[tired marsh]

to read pins with blinka, you would use digitalio

[civic rune]

I want to detect when this pin is shorted to ground by my button, would I need something like:

import board
import os
import digitalio



check_pin = digitalio.DigitalInOut(board.D3)
check_pin.DIRECTION = digitalio.Direction.INPUT

or would it be INPUT_PULLUP?

[tired marsh]

you can do this:

check_pin = digitalio.DigitalInOut(board.D3)
check_pin.direction = digitalio.Direction.INPUT
check_pin.pull = digitalio.Pull.UP

[civic rune]

ahhh ok, and I want pullup here why? I'm trying to understand the various guides I'm trying to merge into one working script

[tired marsh]

though I tend to prefer this:

check_pin = digitalio.DigitalInOut(board.D3)
check_pin.switch_to_input(digitalio.Pull.UP)

[civic rune]

what does check_to_input() do?

[tired marsh]

(typo)

[civic rune]

ah switch to input

[tired marsh]

you want a pull up so that the value when the button is not pressed is high (True), and when shorted to ground it becomes low (False)

[civic rune]

ahh ok

if I configure the LED that goes with the button in my script that runs on startup, will it be configured the same when my shutdown code runs?

like I'd still need to run something like
led_pin = board.D13 in my shutdown code so that I can talk to the pin, but do I need to worry about config there?

[tired marsh]

you still need a DigitalInOut instance to talk to the pin

[civic rune]

ok cool

[tired marsh]

(board.D13 is an int)

[civic rune]

let me see if I can get a script together

would you use

led_pin = board.D13
led_pin.switch_to_output(digitalio.Pull.UP)

?

I just want it to run an LED

[tired marsh]

just True or False, to turn the LED on or off

[civic rune]

I don't need to worry about output vs input?

[tired marsh]

you need to set it to output, but the output value is True or False, not a Pull.*

[civic rune]

Ahh ok

so

led_pin = digitalio.DigitalInOut(board.D13)
led_pin.direction = Output

?

[tired marsh]

led_pin = digitalio.DigitalInOut(board.D13)
led_pin.switch_to_output(True)

[civic rune]

ahh

[tired marsh]

oops no

I copied too fast

[civic rune]

that was my next question

how would you detect a falling edge? Debounce lib?

[tired marsh]

yes adafruit_debounce is fine for a single (few) pin, or you can use the keypad module

[civic rune]

how can I check if either comes with blinka?

[tired marsh]

keypad is part of blinka, Debounce is pip install adafruit-circuitpython-debouncer

[civic rune]

ah ok, might as well use keypad

haven't used it before, time to readthedocs it

[tired marsh]

keypad checks in the background and gives you a list of events to go through, Debouncer requires to call button.update() on it and then just check button.fell (or rose)

the learn guide is a good source: https://learn.adafruit.com/key-pad-matrix-scanning-in-circuitpython

[civic rune]

"and say whether the pins become True or False (high or low logic value)" in my case it would be low right? since I'm shorting a pin to ground?

[tired marsh]

yep

[civic rune]

ok let me dig thru this more

thx so much

hmm so something like:

import keypad
import board

button = keypad.Keys((board.D13,), value_when_pressed=False, pull=True)

Does this make the pin pulled up?

also what's the trailing , in ((board.D13,),.... for?

[tired marsh]

that's a one-element tuple

[civic rune]

I would have thought a one element tuple would just be (board.D13)? What does the extra , do?

[tired marsh]

parenthesis alone are just for grouping: (1) == 1 but (1,) is the tuple version of [1]

[civic rune]

ahhhhh

ok

does pull = True turn the pin into a pulled-up input?

without me having to do that in digitalio?

[tired marsh]

yes

[civic rune]

nice, I just love adafruit software so much

let me hack together a script real fast

Here's what I've got from googling things

#!/bin/python

import board
import subprocess
import digitalio
import keypad


# check_pin = digitalio.DigitalInOut(board.D3)
# check_pin.switch_to_input(digitalio.Pull.UP)


button = keypad.Keys((board.D13,), value_when_pressed = False, pull = True)

led_pin = digitalio.DigitalInOut(board.D13)
led_pin.switch_to_output(True)

while True:
    
    event = button.events.get()
    
    if event:
        break
led_pin.value = False
subprocess.Popen(['sudo shutdown','-h','now'])

[tired marsh]

if you are just waiting for the button to be pressed once, you probably don't need keypad or debouncing

check_pin = digitalio.DigitalInOut(board.D3)
check_pin.switch_to_input(digitalio.Pull.UP)
# waiting for button to be pressed
while check_pin.value:
  time.sleep(0.01)
# button was pressed

[civic rune]

interesting

[tired marsh]

(I put a sleep to avoid a tight loop that would pointlessly poll as fast as possible)

(0.1 would likely work too)

[civic rune]

and the raspi automagically runs this at the same time as my other code?

[tired marsh]

other code ?

[civic rune]

I have a main script that runs on start as well

doing completely unrelated things

[tired marsh]

yup if they are started independently, they run independently, each in their own process and their own virtual machine and all that

[civic rune]

perfection

ok, what should I google to understand what the -h parameter is doing? I tried googling the string and it didn't get me where I wanted

[tired marsh]

you can type man shutdown and look through it

[civic rune]

ah removing "raspberry pi" from the search fixed the issue

[tired marsh]

(that would also work in google in fact)

[civic rune]

as it's a generic linux command

ok so I do want -h as I want to be able to pull the power after shutdown

is there anything wrong with use keypad here? I kind of like it

[tired marsh]

no I don't think there's anything wrong

[civic rune]

what does

if event:

check?

that the events list isn't empty?

[tired marsh]

it just feels a little unnecessary to me, if you are just waiting for the first press, then stop, there's not really a point in an event queue

[civic rune]

ok makes sense

Hmm let me re-write

[tired marsh]

yeah, in theory you should then check that the event is pressed

(even though it shouldn't be possible to be anything else)

[civic rune]

could it be:
if event and event.pressed

[tired marsh]

right

[civic rune]

hmm ok, I'll try that and if it doesn't work I'll just poll the value every .1s

[civic rune]

Do the pins on the pi header expose the pins on the screen insert parts of the pi?

[ruby night]

Sorry -- I don't understand the question. What do yo mean by "screen insert parts of the pi"?

[faint sparrow]

Idk why it doesn't works 😦

Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Collecting discord.py
  Using cached https://files.pythonhosted.org/packages/97/3c/2a97b47fd8839f8863241857bbd6a3998d1de1662b788c8d9322e5a40901/discord.py-0.16.12.tar.gz
Collecting aiohttp<1.1.0,>=1.0.0 (from discord.py)
  Using cached https://files.pythonhosted.org/packages/09/5a/7b81ea8729d41f44c6fe6a116e466c8fb884950a0061aa3768dbd6bee2f8/aiohttp-1.0.5.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-Q7i8g7/aiohttp/setup.py", line 60, in <module>
        raise RuntimeError("aiohttp requires Python 3.4.2+")
    RuntimeError: aiohttp requires Python 3.4.2+
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-Q7i8g7/aiohttp/
pi@raspberrypi:~ $ ```

I mean idk what is that error code 1

Nvm I just found out why

aiohttp needs my Python to be updated

[faint sparrow]

Nvm after some updates I still have this problem, I'm installing aiohttp

Ohhhhh I was using pip instead of pip3

That's why

Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Collecting aiohttp
  Downloading https://files.pythonhosted.org/packages/2e/e6/9175733f42cec4f2cd6834564517f2f6260e27dab5edb75afdaa66f101bb/aiohttp-2.3.1.tar.gz (1.1MB)
    100% |████████████████████████████████| 1.1MB 63kB/s 
  Installing build dependencies ... done
aiohttp requires Python '>=3.4.2' but the running Python is 2.7.16
pi@raspberrypi:~ $ 

It's when I tried to install aiohttp

[steady rose]

can use --version to double check what version gets mapped

python --version
pip --version

or, in general, can use python3 and pip3 to be explicit

[heady cedar]

I'm still trying to get the hang of installing CircuitPython libraries on the Raspberry Pi. I have blinka up & running, but must be doing something wrong when trying to add the adafruit_debouncer library. I've tried to add it with:
pip install adafruit_debouncer (figure pip is fine since I'm using Bullseye), and pip3 install adafruit_debouncer just in case that was the issue.
Both cases the error was something like:
ERROR: Could not find a version that satisfies the requirement adafruit_debouncer ERROR: No matching distribution found for adafruit_debouncer
Thanks for fixing my thinking on this.

[tired marsh]

it's pip install adafruit-circuitpython-debouncer

they all follow that naming scheme on pypi, it's usually explained in the readme, but that is missing from debouncer apparently, see for example this other library: https://circuitpython.readthedocs.io/projects/apds9960/en/latest/#installing-from-pypi

[heady cedar]

Thanks @tired marsh I checked the readme & didn't see it there, but am too green to know the naming scheme. Appreciate you setting me on the right path. Cheers!

[heady cedar]

I know the CircuitPython audioio library isn't supported on the Raspberry Pi, and I've used the recommended PyGame. Why don't the Pi's use audioio? I want to make sure I'm sharing the right info with my students. Thanks!

[civic rune]

It was late for me and I couldn't English. This header/socket/thing

[raw solar]

That's DSI, Display Serial Interface, and it is not exposed on the header

[civic rune]

Ah ok, so I'd need a ribbon cable from here to my display?

Also how does that connector work? It doesn't seem to come all the way out on mine

[raw solar]

Yeah, ribbon cable. The black part pulls out some, you put the ribbon in, and push it back in

[civic rune]

Ahh ok thanks

I want to add a display to my project, can blinka handle that or is that a CPython thing?

[raw solar]

DSI displays are usually handled by the OS, not sure if Blinka/CPython can work with them? SPI displays would connect to the header and could be controlled with them

[civic rune]

Ahh ok, I need a refactor anyways

How would that work if I'm using the SPI pins for shift registers?

[raw solar]

You should be able to use other pins for SPI

[civic rune]

Ahh ok

Thx

[raw solar]

np :D

[sturdy blade]

from smbus import SMBus
from time import sleep
import _thread
#import time
from flask_cors import CORS, cross_origin
from flask import Flask

bus = SMBus(1)
app = Flask("main")
cors = CORS(app, resources={r"/": {"origins": ""}})
app.config['CORS_HEADERS'] = 'Content-Type'
@app.route('/', methods=['GET','OPTIONS'])
@cross_origin(origin='',headers=['Content-Type','Authorization'])

#def safe_exit(signum, frame):
#exit(1)
#ads7830_commands = [0x84, 0xc4, 0x94, 0xd4, 0xa4, 0xe4, 0xb4,0xf4]
def read_ads7830():
bus.write_byte(0x4b, 0x84)
return bus.read_byte(0x4b)
X = ""
def getValue_t(delay):
global X
while True:
value =read_ads7830()
print(value)
sleep(delay)
X = value
_thread.start_new_thread(getValue_t,(1,))
def home():
global X
strs = X
return "{value:"+strs+"}"
CORS(app)
if name == "main":
app.run()

TypeError: The view function did not return a valid response. The return type must be a string, dict, tuple, Response instance, or WSGI callable, but it was a int.

how can I solve this error

[civic rune]

Hey @sturdy blade what are you trying to accomplish and what errors are you getting?

Oops sorry

I'm on mobile and it didn't show immediately

My b

It will make it easier to help if you edit your code block post and add the following:

```py
Your code
```

[sturdy blade]

'''py

[civic rune]

Ah those are back ticks

On a normal keyboard they are the same key that gives you the ~

[sturdy blade]

from smbus import SMBus
from time import sleep
import _thread
#import time
from flask_cors import CORS, cross_origin
from flask import Flask

bus  = SMBus(1)
app = Flask("main")
cors = CORS(app, resources={r"/": {"origins": ""}})
app.config['CORS_HEADERS'] = 'Content-Type'
@app.route('/', methods=['GET','OPTIONS'])
@cross_origin(origin='',headers=['Content-Type','Authorization'])

#def safe_exit(signum, frame):
    #exit(1)
#ads7830_commands = [0x84, 0xc4, 0x94, 0xd4, 0xa4, 0xe4, 0xb4,0xf4]
def read_ads7830():
    bus.write_byte(0x4b, 0x84)
    return bus.read_byte(0x4b)
X = ""
def getValue_t(delay):
    global X
    while True:
        value =read_ads7830()
        print(value)
        sleep(delay)
        X = value
_thread.start_new_thread(getValue_t,(1,))
def home():
    global X
    strs = X
    return "{value:"+strs+"}"
CORS(app)
if name == "main":
    app.run()

[civic rune]

Neat perfect thanks

[sturdy blade]

Thank you

good to know

[civic rune]

No problem. I don't have experience with flask but hopefully someone stops by

You can also do inline code blocks, without the ability to use special formating with single back ticks like so: `code snippet` becomes code snippet

[sturdy blade]

okay. thanks

'code' snippet'

[civic rune]

Use back ticks `

[sturdy blade]

code snippet

there

help-with-flask-thread

[late holly]

In order to get the RPLidar to work with PiTFT, I go in terminal to directory RPLidar/pi_rplidar/CircuitPython_7.x and type python display_lidar_pi.py. Is there a way to get this executed automatically on powering up the RPi4?

[civic rune]

Yes!

There's a guide on adafruit for doing it but honestly I've gotten feedback that it does it wrong.

It's called something like "make a program run on your tiny computer". You want the systemd part of the guide. However my understanding is that it should use /etc/systemd/system instead of /lib/systemd/system

I think if you follow the guide but use /etc/systemd/system for your .service and make sure to link it properly it will work

[late holly]

Thanks @civic rune - Can you point me to this guide? link if available

[civic rune]

I'm on mobile, let me see if I can find it

[tired marsh]

https://learn.adafruit.com/running-programs-automatically-on-your-tiny-computer

[civic rune]

That's the one

Take my warning about /lib/ vs /etc/ with a grain of salt. I got it working the /lib/ way, I'm still trying to learn how to undo what I did

Also there's a bug in that guide, idk if it's been fixed, but in single page mode the link to the systemd method links higher in the guide than it should. You'll have to scroll down

[late holly]

Thanks @civic rune and @tired marsh. I will check it

[tired marsh]

the internal links are a little wonky possibly due to images loading as it scrolls, increasing the height of the page

[civic rune]

Ah cool good to know

[late holly]

I thought it will be ok, if I am not near my Pi and in headless mode, to ssh and execute the program. I see the attached error. Anything I can do to fix this? @tired marsh @civic rune

[civic rune]

Not sure I've only used pygame to play audio. It's a deep program with lots of capabilities I haven't needed

Also @late holly the main issue with using /lib/ is that it's reserved for system stuff and can be automatically overwritten without notice

[late holly]

ok

[pliant pebble]

Does anyone know if the RPI Imager flashes Bullseye on to the SD card, or the previous version?

I'm assuming Bullseye, but I'm not sure

[late holly]

A few days ago, I used the RPi Imager to flash an image and it flashed the BullsEye version

[ruby night]

bullseye is the current images

[civic rune]

Does anyone mind weighing in on some advice I got in another discord regarding the pi?

Basically it boiled down to: when setting up a program to run on startup you should use /etc/systemd/system rather than /lib/systemd/system because /lib/ can be automatically overwritten. I am too new to Linux and am still parsing the docs to try to understand

[pliant pebble]

Cool

[pliant pebble]

Right

[pliant pebble]

That's the right advice IMHO

[dark rivet]

https://downloads.raspberrypi.org/raspios_lite_arm64/images/raspios_lite_arm64-2021-11-08/

Is this the current headless 64 bit rpi os?

I can't seem to get to it on my pi zero 2 via serial cable. I added enable_uart=1 to config.txt

[dark rivet]

Nevermind I was able to get to it via ssh

[tulip wedge]

Hi guys, I'm new in terms of programming for a microcontroller. I'm trying to implement some sort of SPI communication. The protocol would allow transmit and receive at the same time if I understand that correctly. My problem is that I have no idea how to programm such a case. Could anyone recommend any tutorials on that topic or can give me some pointers? Would I have to split sending and receiving between cores or is there a simpler solution my newbie brain just can't come up with? :D

[hardy plaza]

Have you already done any reading about the SPI interface itself? There's lots online, e.g., https://www.analog.com/en/analog-dialogue/articles/introduction-to-spi-interface.html

[tulip wedge]

Yeah, I read about the Interface allready. My problem lays more on the programming side of things :) Like how can I get my program sending and receiving at the same time. I wouldn't have trouble if it would only be either sending OR receiving data, but I have no idea how to handle the use case when both happens at the same time

[hardy plaza]

Where does the requirement that they send and receive at the same time come from? Does this have to be literally at the same time, or can there be some time delay between? What actually is the requirement?

And what programming language? And how do you plan to keep the input and output buffers populated/drained?

There's too much ambiguity in your question to provide any real answer, we'd need more information to help you.

[umbral sable]

SPI has a data line in each direction, so every transfer can send bits from the master to the slave and the slave to the master at the same time. In many cases, only one of these is used, though, if there's no data to send in that direction, and the bits are just discarded, so it looks like a regular send or a receive command.

[civic rune]

so, to circle back to this real quick. I want to undo my service in /lib/systemd/system. Is it enough to run sudo systemctl disable myservice.service? Do I need rename the service when I make a new one in /etc/systemd/system? What do I need to do with the symlink to my original service?

[solemn finch]

I think disable will delete the symlink

[civic rune]

oh nice ok

So do I need to rename the service?

and can I just use:
cd /lib/systemd/system
mv myservice.service /etc/systemd/system
?

[solemn finch]

I don't know enough about it

[civic rune]

no worries thanks

[solemn finch]

I'd assume you want it in lib and then do a new symlink

[civic rune]

I read elsewhere that /etc/ is the right place

I don't know enough to make a definitive statement though

[solemn finch]

I only ever use enable and disable with systemd

[civic rune]

ok

[delicate holly]

Hey, I'm trying to use Blinka to control two SPI devices on an RPi 4 and the clock select behavior isn't what I expect. Does anyone know of a reason why board.CE0 and board.CE1 wouldn't switch correctly?

Edit: Looks like there's someone with a similar problem:
https://github.com/adafruit/Adafruit_CircuitPython_RGB_Display/issues/95

I'm not sure whether I'm doing something wrong, multiple displays just aren't supported, or there's a bug in the lib.

[subtle pewter]

How to Fix it

Help

[civic rune]

you'll need to provide a lot more info

[hard marsh]

Can I program the feather M0 from an Aruduino IDE on a Pi Zero? My hope is I can just plug it into the uUSB port like a peripheral. Maybe OTG cable?

[solemn finch]

I think you should be able to with an otg cable

to make the pi act as usb host

[civic rune]

where do symlinks live? Or do I misunderstand how they work? I want to remove all traces of my old method of running a program on start

[hard marsh]

@solemn finch Thanks!

[civic rune]

sudo systemctl status myservice.service didn't provide any useful info

[umbral sable]

Symlinks just live on the filesystem, so they'll show up in a directory listing.

[civic rune]

ahh ok what can I google to find the answer?

or rather what is a directory listing?

I also need to figure out what the symlink's name is.

I ran ls -l and got:
-rw- r -- r -- 1 root root for my service. are r,w, and rw related to read/write privileges?

[umbral sable]

The output of ls is indeed a directory listing... a list of the files in a directory. And yes, the rw information is telling you the owner, group, and world access permissions for the file.

[civic rune]

ah ok thanks I thought it was something like that but I'm pretty ignorant about how real computers work

ok

Are there commands I can run to find the name and location of the symbolic link associated with my particular .service

[umbral sable]

A symlink is just a "this file is actually the same as this other file, so read it from there" redirection.

[civic rune]

Ah yeah I have had the feeling that I don't really grok what's going on

from stack overflow I found find -L /var/www/ -type l can I just replace /var/www/ with /lib/systemd/system?

ah that returned nothing.

ah there we go. xtype, not type

maybe I don't even need to find and delete the symlink. hm

can't seem to find anything with find -L /lib/systemd/system -xtype l

hmm ok starting at a different point I ran
sudo nano /etc/systemd/system myservice2.service and I'm getting a new warning that:
["/etc/systemd/system" is a directory]

[late holly]

I have a PiTFT connected to a RPi4. Pins 1 to 26 of the RPi are used by the PiTFT. I would like to connect a StemmaQT BNO055 over I2C from the RPi4. Can I use Pins 27 and 28 as SDA and SCL. I see pin 30 is GND. Vin for BNO055 specifies 3.3 to 5V. I guess I will have to use pin 1,2 or 4 from RPi. What is recommended for good operation of the BNO055 with RPi4?

27 and 28 are stated as SDA and SCL for EEPROM. What is that?

Or is it necessary to use pins 3 and 5 for SDA and SCL for the BNO055? I am hoping that they are not used by the TFT display ...

[civic rune]

weird. I ran sudo nano /etc/systemd/system but when I wrote the file out, it doesn't appear there.

but when I run sudo nano /etc/systemd/system myservice2.service it opens it just fine

[civic rune]

ok it seems like I was opening a directory like a file?

In case anyone needs this info, the problem was with my nano command I needed to run
sudo nano /etc/systemd/system/myservice2.service

[civic rune]

silly question, I ignored the advice to change my default user and password on my pi. I see how to change the PW but not how to change the username

actually let me google that, sorry

is it actually necessary to change the default username?

[ruby night]

Not in my opinion.

Password yes

[civic rune]

thanks

it seems like a mild hassle to change the username. Default is either pi or raspberry right?

[late holly]

default username is pi

[civic rune]

thx

[humble marsh]

The problem with the chip-select lines is described here: https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/spi-sensors-devices

[ripe berry]

I tried to install the raspberry pi video looper https://learn.adafruit.com/raspberry-pi-video-looper but it said some directories didn't exist during the installation. I'm thinking some parts at external web sites have been removed because it's pretty old. Is there a newer software package that can play videos automatically from a USB drive?

[ripe berry]

Actually, this one works! https://videolooper.de/

[civic rune]

what happens to the GPIO pins when I run subprocess.Popen(['sudo',' shutdown','-h','now'])? I am using an LED to determine when I've shutdown the pi. My full shutdown monitor script is:

#!/bin/python

import board
import subprocess
import digitalio
import keypad
import time

check_pin = digitalio.DigitalInOut(board.D3)
check_pin.switch_to_input(digitalio.Pull.UP)


#button = keypad.Keys((board.D13,), value_when_pressed = False, pull = True)

led_pin = digitalio.DigitalInOut(board.D13)
led_pin.switch_to_output(True)

while True:
    time.sleep(.1)
    #event = button.events.get()
    
    if not check_pin.value:
        break
led_pin.value = False
subprocess.Popen(['sudo',' shutdown','-h','now'])

will the pi reliably keep board.D13 low when it's shut down in this manner?

here board.D3 is connected to ground via a switch

[humble marsh]

the pins may go to an input, floating state. That is typical of microcontrollers, because it stops drawing power. You may want to use an external pull-up or pull-down.

[civic rune]

For the LED?

the LED pin rather

in this case board.D13

[humble marsh]

Is D13 attached to the RPi LED pin? I thought you meant it was just a random pin. If the LED remains illuminated, then that pin may be treated specially.

[civic rune]

Ah no it's attached to an external LED illuminated switch I'm using as an off button

my goal was to have the last thing done before the subprocess.Popen() shutdown command to be turning off the LED on the switch

[humble marsh]

Have you tried this already? I imagine the LED will go out, because D13 will become a high-impedance input, floating, with no pullup or pulldown.

[civic rune]

I haven't yet, I've got some physical system building to do first. But I'm so used to CP MCUs that can just be shutdown safely with a pull of a cord, that I'm psyching myself out as to whether this will work or not. I will try soonish.

I also want to set the shift registers I'm working with to a known state that turns off the relays they are driving. If I have imports and usage of adafruit_74hc595 in my main code and and my shutdown monitor code, will they interfere with each other?

[civic rune]

for my shutdown code, it would be something like:

#!usr/bin/python
import board
import digitalio
import board
import adafruit_74hc595
import time

latch = digitalio.DigitalInOut(board.D5)
sr = adafruit_74hc595.ShiftRegister74HC595(board.SPI(), latch, number_of_shift_registers = 2)
check_pin = digitalio.DigitalInOut(board.D3)
check_pin.switch_to_input(digitalio.Pull.UP)
led_pin = digitalio.DigitalInOut(board.D13)
led_pin.switch_to_output(True)

while True:
  time.sleep(0.1)
  if not check_pin.value:
    break
sr.gpio = bytearray(b'\xff\xff')
led_pin.value = False
subprocess.Popen(['sudo','shutdown','-h','now'])

my concern is with the spi bus, will board.SPI() be unavailable to my shutdown code because it's previously used in the main code?

[faint sparrow]

I have some difficulty with being able to tell if I need a pi or an arduino to use a camera. What would be the general guidelines ?

I know that the PI isn't realtime with arduino and for driving it seems like I couldn't use a pi for that particular use case

[spice kayak]

I'm not in the position where the pi is accessed by console. So I normally disable ssh and enable firewall. Then drag my feet on changing user/pass 😅

[faint sparrow]

and does the pi interact more naturally with a linux base station (x64 ubuntu in my case) or it doesn't matter much that the OS matches ?

I accidently found an old PI2+ in my home

Like with archeology

[humble marsh]

I don't know how the underlying library works, but I would hope that if you close what you're doing in the other program, even forcefully, it will free up. Obviously something to test.

[civic rune]

hm, ok I'll set up a test. I want these to run concurrently, which is why I had a concern

I wonder if I should just add my shutdown code to the main code...

avoid the issue entirely

since it's a pi I could learn how async works I guess and write an asynchronous routine to deal with it... hmmm stuff to deal with once it's actually working

[civic rune]

wanted to have someone briefly look at my test code before I short a pin to ground. It's:

import board
import digitalio
import time

check_pin = digitalio.DigitalInOut(board.D3)
check_pin.switch_to_input(digitalio.Pull.UP)
led_pin = digitalio.DigitalInOut(board.D13)
led_pin.switch_to_output(True)

while True:
  time.sleep(.1)
  if not check_pin.value:
    print("pressed")

anything look wonky?

looking at circuitpython.readthedocs I see there is a parameter for switch_to_output called DriveMode. When is it appropriate to use this parameter?

it seems I want PushPull but I'm not sure

ah it's that way by default, nevermind

[steady rose]

is the time.sleep for simple debouncing? if so, can put it in the if statement so you aren't slowing down the reading of the pin state.

[civic rune]

I won't likely have the time.sleep in there when I incorporate this into my main code. I decided to just have my main task also handle shutdown

how would I incorporate it into the if statement? have a time.monotonic() var that I compare to?

[steady rose]

  if not check_pin.value:
    print("pressed")
    time.sleep(0.1)

[civic rune]

ohhhhh

ok

[steady rose]

it's ok to read the pin as fast as possible

but you'd want to limit to resulting action taken

once the pin is actually pressed

[civic rune]

ok cool, does anything else in the code seem like it would cause an issue? I am wary of shorting a pin to ground

[steady rose]

looks ok

it's not really shorted to ground, since there's the pullup resistor

[civic rune]

oh ok

so it makes a connection between 3.3V and ground thru the pullup?

[steady rose]

correct

[3.3V]--(resistor)--(IO pin)--(button)--[GND]

when button is open, IO sees 3.3V

when button is closed, IO sees GND

[civic rune]

hmm ok. IDK why but pullups/pulldowns have always been a frustration of mine to understand.

so you'd run this code as is?

or rather let me make the changes you mentioned

this instead

import board
import digitalio
import time

check_pin = digitalio.DigitalInOut(board.D3)
check_pin.switch_to_input(digitalio.Pull.UP)
led_pin = digitalio.DigitalInOut(board.D13)
led_pin.switch_to_output(True)

while True:
  
  if not check_pin.value:
    print("pressed")
    time.sleep(.1)

[steady rose]

might help for pull up/down?
https://learn.adafruit.com/circuit-playground-digital-input/floating-inputs

built in pull up/downs don't always exist

so helps to see all the hardware external

internal is just "this is a common and important use case, so let's put them inside so it's not necessary to bolt on an external one"

functionally, it's the same thing

[civic rune]

ok cool thanks. just to burden you with my anxiety one more time, does this code look right? Like when I connect the pin to ground I'm not creating a near 0-ohm short because of the pullups?

[steady rose]

correct. it'll be whatever ohms the pull resistor is.

[civic rune]

also why do I want an input for check_pin? so I can read it?

[steady rose]

yep

the thing you are interested in is going "in" to the board, thus an input

"read" = input (for button, etc.)
"write" = output (for LEDs, etc.)

the property feature in python makes the read/write syntax simple

check_pin.value is all you need for a read

check_pin.value = True is all you need for a write

[civic rune]

ahh so there's a decorator going on there. that makes sense

ok time to run the code and see what happens.

hey it works! All that hemming and hawing for nothing!

[steady rose]

code seems OK. led_pin is not used.

[civic rune]

it will be in the main code. Although I notice that my LED isn't lit...

[steady rose]

but otherwise, should print "pressed" when D3 goes low

[civic rune]

let me pull up my board and see if I just wired the LED backwards or some such

[steady rose]

there's no code setting led_pin, so maybe it's just low

[civic rune]

ohhhh

let me fix that and try again

[steady rose]

you're setting it up for an output ok, but then don't actually output anyting

[civic rune]

For some reason I assumed that switch_to_output(True) would make the value true. but i assume that's not the case

hmmm it's still not lighting with led_pin.value = True

long lead should go to + and short lead to -, correct?

[steady rose]

you're correct, it should set the default value:
https://circuitpython.readthedocs.io/en/latest/shared-bindings/digitalio/index.html#digitalio.DigitalInOut.switch_to_output

long +, short -

correct

do you also have a current limiting resistor inline with LED?

[civic rune]

I do, 150 ohms

I might be using the wrong pin. let me check my board

against pinout.xyz

ahh I'm using GPIO 17

[steady rose]

D13 is here

[civic rune]

so I need board.D17 right?

[steady rose]

your code is for D13. up to you which to change.

code or wiring

they just need to match

how'd you come up with 150 ohms for the LED resistor?

[civic rune]

I wanted 10 mA of current to keep me well below the max output of a GPIO. Voltage drop for the LED is 2 V

ok it lights up but it's pretty dim, maybe I should use a 100 ohm or even lower. Hmm

actually if you look head on it's fine

[steady rose]

in general, you don't want to power LEDs directly from GPIO pins.

even though there are a million demo guides that show this

[civic rune]

hmm what would you use? A mosfet?

[steady rose]

it generally works because LEDs dont' require a lot of current, and most boards can source the required few mA's needed.

[civic rune]

I read that you can get 20 mA out of a pi pin, so I went with half to be safe

[steady rose]

yep. in the long run, better to switch setup to using a power transistor and controlling that via the GPIO pin.

[civic rune]

I have a few hardware bugs that I need to fix so this just adds them to the list

[steady rose]

don't worry about it at this point then