Timing Issue | adafruit | Page 1

lone trellis Sep 22, 2021, 4:51 PM

#

I am tasked with playing a song and switching 12 relays to different configurations during the song

#

I'm using a pi 3 A+, although it's overkill.

#

I went thru the song and carefully marked the time that the lyrics change, down to the ms.

#

I'll upload the code so people can see it

#

one sec, I have to log in to discord on my pi, it's taking a bit

#

a bit was an understatement!

#

I feel like I've gone back in time 20 years to the dial up days

#

Unfortunately my wrinkles didn't disappear

wintry badge Sep 22, 2021, 5:00 PM

#

haha yeah discord is a bit of a rough program for the pi

lone trellis Sep 22, 2021, 5:00 PM

#

hmm

#

I could type out my code, but there is a huuge dictionary in there. I suppose I could type out just the important bits

wintry badge Sep 22, 2021, 5:01 PM

#

That would work, but make sure either before or after you highlight the problem, it'll make it easier to understand what to look for while reading your code

lone trellis Sep 22, 2021, 5:02 PM

#

Ah Ill do that now

#

So, my code opens the mp3 fine, plays it fine, but all the transitions seem to be off by one?

#

I've also written a short program to test the tlc59711 that I am using to trigger relays (testing setup is just driving LEDS), and I know it's working fine

#

here's the important bits

#

#imports and creation of large ordered dictionary. Keys are time in ms, values are lists of 12 #0's or 1s representing states of the relays

def sequencer(values):
  values = [x * 65535 for x in values]
  tlc59711[3] = (values[11],values[10],values[9])
  tlc59711[2] = (values[8],values[7],values[6])
  tlc59711[1] = (values[5],values[4],values[3])
  tlc59711[0] = (values[2],values[1],values[0])

  tlc59711.show()
while True:
  pygame.mixer.music.play()

  while pygame.mixer.music.get_busy():
    values = [0,0,0,0,0,0,0,0,0,0,0,0]
    for key in time_stamp_dict.keys():
      if pygame.mixer.music.get_pos() <= key:
        values = time_stamp_dict[key]
        break
    sequencer(values)

#

any syntax errors are from typing it out, it runs fine

fresh lion Sep 22, 2021, 5:16 PM

#

dictionaries are not ordered

lone trellis Sep 22, 2021, 5:17 PM

#

oops it's an ordered dict

#

I'll edit above to indicate

fresh lion Sep 22, 2021, 5:17 PM

#

and I don't think that is the problem looking at it closer

lone trellis Sep 22, 2021, 5:26 PM

#

I thought I did timing this way successfully in another project, but now I'm questioning that

#

I'm gonna try it with a slew of if-elif statements

#

it'll be gross but that's OK

fresh lion Sep 22, 2021, 5:32 PM

#

Are you off by one ahead or behind?

lone trellis Sep 22, 2021, 5:33 PM

#

Uhhh let me check again and see

#

I think I'm one ahead, the LEDs are lighting up early

fresh lion Sep 22, 2021, 5:34 PM

#

Could just be a slight timing issue

lone trellis Sep 22, 2021, 5:35 PM

#

yeah I wanted to avoid going thru and timestamping again, hoping it was some simple coding error

#

it took me houuuuurs

#

but if it's gotta be done, it's gotta be done

#

Thanks for your help, I'll post here again if I find I just timestamped wrong

mystic sage Sep 22, 2021, 5:36 PM

#

You can upload your code file(s) with the + at the left, no reason to retype it here

lone trellis Sep 22, 2021, 5:36 PM

#

Oh, I'm writing it on the pi, but I couldn't get discord to load on the pi

#

Oh wait....usb drive!

mystic sage Sep 22, 2021, 5:37 PM

#

what is the other computer you have?

#

Mac, Windows, Linux?

lone trellis Sep 22, 2021, 5:38 PM

#

Windows

#

📎 12days.py

mystic sage Sep 22, 2021, 5:39 PM

#

you could enable ssh server on the Pi and use pscp (comes with Putty) to copy files back and forth

#

https://success.tanaza.com/s/article/How-to-use-SCP-command-on-Windows

lone trellis Sep 22, 2021, 5:39 PM

#

Oh cool!

mystic sage Sep 22, 2021, 5:40 PM

#

or https://www.dexterindustries.com/howto/how-to-transfer-files-to-your-raspberry-pi-from-a-pc-computer/

#

https://www.makeuseof.com/tag/copy-data-raspberry-pi-pc/

dapper thunder Sep 22, 2021, 5:40 PM

#

get the music play time
get_pos() -> time
This gets the number of milliseconds that the music has been playing for. The returned time only represents how long the music has been playing; it does not take into account any starting position offsets.```
From the looks of the docs, it might be calculating current ms based on time difference from the play() command, not the actual music start.

lone trellis Sep 22, 2021, 5:41 PM

#

hmm

dapper thunder Sep 22, 2021, 5:42 PM

#

I could see your code being late if latency was an issue, but if it's early it's most likely some sort of offset problem

#

And if the offset is consistent enough, maybe all it takes is to insert a fixed offset into your key comparison

lone trellis Sep 22, 2021, 5:43 PM

#

so...use onboard RTC?

#

hmm

lone trellis Sep 22, 2021, 5:43 PM

#

dapper thunder And if the offset is consistent enough, maybe all it takes is to insert a fixed ...

But I'd need to figure out the offset, if that is the problem?

dapper thunder Sep 22, 2021, 5:44 PM

#

You could also just calibrate it manually, test a couple of numbers and see if it's still off

#

Assuming the offset is consistent

#

I know it's common in rhythm games like DDR to set a global offset to align arrows on the screen with the actual audio

lone trellis Sep 22, 2021, 5:45 PM

#

heres a screenshot of the shell, you can see the transition in real time. the ms are from get_pos()

#

#

so the transition seems to be happening at the right time??

#

compared to my dict

dapper thunder Sep 22, 2021, 5:46 PM

#

but it feels off when you listen to it?

lone trellis Sep 22, 2021, 5:47 PM

#

yeah, I can take a video. The first LED is supposed to light up when "A partridge in a pear tree" starts

#

since I'm getting my phone out, I'll also reward you lovely folks with a picture of my cute dog

dapper thunder Sep 22, 2021, 5:49 PM

#

No, I believe you. How was the dict written?

lone trellis Sep 22, 2021, 5:49 PM

#

I posted my code above

#

it's a bit long so may need to download it

dapper thunder Sep 22, 2021, 5:50 PM

#

No, but how did you come up with the timings for each entry? Did you write it yourself?

lone trellis Sep 22, 2021, 5:51 PM

#

oh yes

#

I went thru the song in audacity and timestamped everything

dapper thunder Sep 22, 2021, 5:52 PM

#

Oh, I see, you're off by a sample

#

THe first light isn't supposed to come on until 11690?

#

Oh nvm

lone trellis Sep 22, 2021, 5:52 PM

#

My video just finished uploading to drive, let me pull it down

dapper thunder Sep 22, 2021, 5:52 PM

#

the key is end time not start

lone trellis Sep 22, 2021, 5:53 PM

#

uhhh I think so

#

I wrote this near the end of my day, so my brain wasn't 100%

#

the first blue light is supposed to come on when "A partridge in a pear tree" starts, and turn off when "On the second day of christmas" starts

#

I will go timestamp it again and re-write the dictionary and see if that fixes it

#

If it does I will be only mildly ashamed

dapper thunder Sep 22, 2021, 6:10 PM

#

I think your dict timestamps are supposed to be start times.

#

Your code is switching to the sample after it exceeds the previous value, so I think all the keys in your dict need to shift up one entry...

lone trellis Sep 22, 2021, 6:19 PM

#

hmm, can that be solved with code?

dapper thunder Sep 22, 2021, 6:20 PM

#

Yes it can, but I can't say it's a clean solution

lone trellis Sep 22, 2021, 6:20 PM

#

if you saw the mechanical system this was controlling, you wouldn't be concerned about cleanliness 🙂

dapper thunder Sep 22, 2021, 6:21 PM

#

        for key in time_stamp_dict.keys():
            if key > pygame.mixer.music.get_pos():
                break
            values = time_stamp_dict[key]

#

Ah wait

#

Fixed

#

Try that?

lone trellis Sep 22, 2021, 6:22 PM

#

oh just a fun tidbit, if you add py after the three ` marks it will do python syntax highlighting

#

or python

#

```py

#

sorry the first three back ticks

#

woot!

dapper thunder Sep 22, 2021, 6:22 PM

#

lol np

lone trellis Sep 22, 2021, 6:22 PM

#

It's a nice feature

#

Ill try that thanks! one sec

lone trellis Sep 22, 2021, 6:24 PM

#

dapper thunder lol np

That seems to have solved it!!!!

#

I'm going to credit you and the rest of the adafruit folks in the manual for this

#

let me get that dog picture too

#

@dapper thunder Dog breath thanks you!

dapper thunder Sep 22, 2021, 6:27 PM

#

Cute

lone trellis Sep 22, 2021, 6:27 PM

#

She loves my work from home days

#Timing Issue