64x32 RGB Matrix Skipping Rows

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coffee_witch
 
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64x32 RGB Matrix Skipping Rows

Post by coffee_witch »

Hello!

I recently purchased a 64x32 RGB LED Matrix - 5mm pitch, with an Adafruit RGB Matrix Bonnet to use with my Raspi 4 (Buster Desktop). I have gotten to the point where I can run the demos, but the matrix skips two rows every two rows (see attachment).

I have been using the provided ribbon cable to connect to the bonnet and the following flags to run the different program.

Code: Select all

--led-gpio-mapping=adafruit-hat --led-cols=64 --led-slowdown-gpio 4
. I have tried different multiplex options, but none of that worked either.

When initially setting up the board (https://learn.adafruit.com/adafruit-rgb ... g-matrices), I misread the instructions and soldered a blob onto the middle pad so it is 'shorted' to 8. While this is necessary for the 64x64 board, I'm not sure if it is causing problems for my project. I attempted to remove the solder after I realized.

One other thing is that positions are overlapping with

Code: Select all

sudo ./pixel-mover --led-gpio-mapping=adafruit-hat --led-cols=64 --led-slowdown-gpio 4
If I move the pixel down, the first two are correct but the next two repeat the same two pixels and then skip two to move onto the next set.

I would really appreciate any help to get this working properly.

Images/Video: https://imgur.com/a/BeTKpPv

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blnkjns
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by blnkjns »

With 32 pixel matrices you need the A,B,C and D address lines, with 64 you also need the fifth E line. I'm not familiar with the Raspberry Pi drivers, but a quick try could be setting things to 32 colums instead of 64. Usually this number is refered to as panel width, not column count, and has to be set at 32 for these panels.

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coffee_witch
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by coffee_witch »

Thanks for the response! Tried using 32 cols and that ended up duplicating the program's results where it's displayed twice on different halves of the board.

Code: Select all

sudlo ./demo -D 0 --led-gpio-mapping=adafruit-hat --led-cols=32 --led-slowdown-gpio 4

I updated the imagur link to include an example of using both 64 and 32 (https://imgur.com/a/BeTKpPv)

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adafruit_support_carter
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by adafruit_support_carter »

Do you have a multimeter that could be used to test if the solder pad removal was fully removed, i.e. the pad is no longer shorted?

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coffee_witch
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by coffee_witch »

Okay I've got my multimeter and I've powered the bonnet separate from the pi so I can reach the soldered area. Where should I place the probes in order to check? I made sure that there are clear divides between the three sections where there is no solder in between them.

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adafruit_support_carter
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by adafruit_support_carter »

This is a basic continuity check and should be done without any power going to the Bonnet. It can be removed as you have in your photo here:
https://i.imgur.com/xrILIJN.jpeg

Then, put the meter in continuity test mode - touch the multimeter probes together and you should here a "beep". That's the indication there's a short. For this particular test, it doesn't matter which of the red/black leads go where - they are just used to test the continuity between two points. "beep" = short, no "beep" = no short.
pads.png
pads.png (88.59 KiB) Viewed 168 times
Touch one probe to 1 and the other probe to 2 - is there a beep?
Touch one probe to 2 and the other probe to 3 - is there a beep?
Touch one probe to 1 and the other probe to 3 - is there a beep?

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coffee_witch
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by coffee_witch »

Hey thank you for the patience, I really appreciate you sticking with me.

1) I tested to make sure that it beeped when the probes touch each other
2) Touch one probe to 1 and the other probe to 2 - No beep
3) Touch one probe to 2 and the other probe to 3 - No beep
4) Touch one probe to 1 and the other probe to 3 - No beep
5) Touch both probes to 1 - beep (this was just to make sure I understood and was doing it properly)

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adafruit_support_carter
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by adafruit_support_carter »

Cool. Good check and it's indicating none of the pads are shorting. They also look good in the photo - but it's amazing how little of a solder whisker is needed to short these out. So was worth being sure they were back to original not shorted state.

OK, as a next step, try powering the matrix through the Bonnet. Connect the matrix power wires to the screw terminals on the Bonnet. And then connect the power supply barrel plug to the barrel jack on the Bonnet.
connections.jpg
connections.jpg (64.51 KiB) Viewed 123 times
So it looks as shown in guide:
https://learn.adafruit.com/adafruit-rgb ... g-matrices

And for testing, use this command:

Code: Select all

sudo ./demo -D0 --led-rows=32 --led-cols=64 --led-gpio-mapping=adafruit-hat --led-slowdown-gpio=4

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coffee_witch
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by coffee_witch »

Okay I changed the power source for the matrix to the bonnet. Unfortunately I got the same behavior as a result.

Updated imagur with video: https://imgur.com/a/BeTKpPv

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adafruit_support_carter
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by adafruit_support_carter »

Inlining photos for ref:
cmd.png
cmd.png (183.14 KiB) Viewed 110 times
pi.png
pi.png (311.07 KiB) Viewed 110 times
matrix.png
matrix.png (649.01 KiB) Viewed 110 times

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adafruit_support_carter
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by adafruit_support_carter »

Any difference if you swap the rows/col config?

Code: Select all

sudo ./demo -D0 --led-rows=64 --led-cols=32 --led-gpio-mapping=adafruit-hat --led-slowdown-gpio=4

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coffee_witch
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by coffee_witch »

Using the given command, I get two separate squares rotating.

Updated Imagur - https://imgur.com/a/BeTKpPv

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adafruit_support_carter
 
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Re: 64x32 RGB Matrix Skipping Rows

Post by adafruit_support_carter »

OK, that makes sense. The previous command was correct. Just wanted to see behavior with data being rearranged.

Let's try a replacement Bonnet. Send an email to [email protected] with a link to this thread and your order number and they can send you a replacement RGB Matrix Bonnet.

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