#Assembly Instructions for max7219 digit pcb system

1 messages · Page 1 of 1 (latest)

woven dove
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I bought a couple of https://shop.mobiflight.com/product/max7219-digit-pcb-system-50cm in connection with the MAX7219 - Breakout System.

Is there a more detailed assembly instruction? I only found this: https://github.com/MobiFlight/mobiflight-pcbs/tree/main/max7219-adapter.

But from that I cannot deduct what's the top side and what's the bottom. I did a guess-assembly but obviously did it wrong, as I cannot get it to display meaningful output in Mobiflight. The initial state displays -.-.-. for the 3-digit kit. Sending test data changes the display but not in a meaningful way.

Thanks for your help!

MobiFlight Shop
MAX7219 - Digit PCB System - 50cm

The Max7219 Digit PCB System comes with

  • WHITE 7-segment digits,
  • the PCB
  • all required connectors, and
  • a flat ribbon cable (50cm)

The digits are plugged into the PCB sockets. Combinations of 3-digit & 2-digit are grouped together to make up the combinations from 3-6 digits:

3-digit PCB - 1 x 3-digit module
4-digit PCB - 2 x 2-digit mo...

west orchid
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look at the silkscreen. it indicates on what side goes what.

woven dove
# west orchid look at the silkscreen. it indicates on what side goes what.

Jeez, for the amateur I am that's not so clear 🙂

I put the cable connector base onto the side with the MF logo, soldering it from the mostly blank side. I only found a "16" on one side of the connector, so I put it opposite to the square soldering hole I figured to indicate Pin 1.
The display sockets I then put onto the side that's mostly blank reading "3 digit module V1.0", then plugging in the display with the bottom to the 3-digit-label.

fiery anvil
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@woven dove ok, I am sorry to hear that!

I will write better documentation for you, I agree it is not easy for a beginner, and also the photo where its assembled is a bit dark. I will likely have something later today.

Did you assemble them all or just one so far?

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also thanks for the feedback!

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actually let me message you since its not really relevant to others

west orchid
fiery anvil
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it should be like this

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so the frontside is the one with the mobiflight logo

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the connector needs to be soldered first:

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So first this:

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align the slot on the connector to the slot on the silkscreen (white) picture on the pcb

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solder it fully agains the pcb (flip over, solder end pins first, and then the rest so it stays straight in place)

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Then solder the digit on the front side, over the logo

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and the 7segment module pins are visible on the back side, next to the connector:

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so they can be soldered now

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pay attention to the orientation of the 7segment module, so that the decimal points align with the "www.mobiflight.com" orientation.

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I think the kit comes with pin headers for the segment too, you can push the pins to the segment "legs" first and then solder them on the pcb, if you want. This way they will align correctly

west orchid
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the idc box goes last

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and your pictures don't show the female pin headers

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it's easier to solder if the box goes last

fiery anvil
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yeah I dont have the headers, I will look up 3d model for them and will put them there

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oh right because of the headers

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but if no headers, you have to do it this way

west orchid
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exactly

fiery anvil
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its not super difficult this order either though

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but you have a fair point

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I would maybe older without headers but yes, I will fix this, will put this version up first

west orchid
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thanks so much

fiery anvil
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I will use an [!INFO] tag 🙂

west orchid
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i will have to sleep now

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still not feeling well

fiery anvil
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@woven dove this is my own repository still, but hopefully these instructions are more throrough?

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We'll link them to the shop page too but we need to sort a few details there first. But for now you can view the documentation on the link

woven dove
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Thanks so much! Indeed I did it exactly mirrored as Sebastian assumed. Looking at the renderings the silk screen suddenly make it so obvious as how to assemble. Interesting how I didn't recognize that before 🙈

west orchid
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I can send you one for free as replacement if you want

woven dove
fiery anvil
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did you assemble them all backwards, or just one?

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disassembling many pins at once can be quite difficult unless you are experienced in soldering

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I am sorry for what happened, I have been there too and the feeling of "oh craaap" when you realize the mistake is not fun

woven dove
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I'm cautious and because of the guess work I did just one. Ok...good to know beforehand, as I'm not experienced in soldering in any way. And no need to feel sorry. I'm seeing it as a learning curve. I wasn't clear about the procedure but instead of asking first I opted to give it a try.

west orchid
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it's gonna be quite hard to unsolder

fiery anvil
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it was a learning curve for us, not at all unreasonable to replace it 🙂

woven dove
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You guys are just great. Then it seems like a good idea to take the offer 🙂

long igloo
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When I solder the connector (black), I put on a counter before soldering and the pins are locked in place and there is no risk of changing the position when the plastic is heated
A little advice that is underrated. 🙂

fiery anvil
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yea, this is what I did also on my drone days when soldering XT60 battery connectors

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always plug in the male/female connector pair before soldering