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Adafruit rbg matrix shield not working
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Adafruit rbg matrix shield not working

by Bobberius on Sat Aug 01, 2020 8:15 am

Hello,

I've recently purchased the Adafruit rgb matrix shield for Arduino and tried testing it today,
But I can't seem to get it working.
I have soldered all de header pins and the connectors onto the board in the right direction.
I am using an Arduino uno (official) with the shield on top of it.
I connected a 32x32 rgb matrix panel with the connector cables it came with to the shield.
The matrix panel works with my raspberry pi so i know that isn't the ptoblem.
I installed the needed libraries and followed the official guide linked here: https://learn.adafruit.com/32x16-32x32- ... rix-shield

To power the matrix panel i used the 5vout and gnd on the shield.

When I run the example code testshapes_32x32 i get wierd flickering lines on my matrix panel. I have attached an image that shows these flickering lines on the panel.

Now am i forgetting something or doing something wrong?
Also in the code it states that i should use #define CLK 8 when using an arduino uno, but is this for an arduino uno WITHOUT the rgb matrix shield or with?

If anyone could help me please, thank you.
Attachments
IMG_20200801_140432.jpg
IMG_20200801_140432.jpg (425.13 KiB) Viewed 49 times

Bobberius
 
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Re: Adafruit rbg matrix shield not working

by dastels on Sat Aug 01, 2020 11:12 am

The #define CLK 8 is specific to the shield.

What are you powering the shield with?

What are you trying to display on the matrix?

Since every 8th line is lit, I suspect a connection problem. Recheck all your soldering. See https://learn.adafruit.com/adafruit-guide-excellent-soldering for more information.

Dave

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Re: Adafruit rbg matrix shield not working

by Bobberius on Sat Aug 01, 2020 11:38 am

Hi dave,

I am powering the shield and arduino with a usb cable connected to my laptop.
And the rgb matrix panel is powered by the shield where it says '5vout' and 'gnd'.
I've tried powering the rgb matrix panel with an external 5v power supply but got the same result.
What i want to display on the panel is what the code does in the example.
i have double checked my soldering points but I'm still a beginner and do not see a mistake at first glance.

Bobberius
 
Posts: 6
Joined: Sat Aug 01, 2020 7:25 am

Re: Adafruit rbg matrix shield not working

by dastels on Sat Aug 01, 2020 12:00 pm

How are you connecting it to the Pi?

Since it works there, my first suspicion is that it's a problem with either power (it needs between 2 and 4 amps depending on the usage) or the data connections.

Powering by USB means you can get typically at most 500mA which is nowhere enough for the matrix. I'm frankly confused by why the shield tries to power power the matrix via the UNO's 5v line. That won't work well unless the matrix is used in a way that won't use much power (generating very little light).

Dave

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Re: Adafruit rbg matrix shield not working

by Bobberius on Sat Aug 01, 2020 12:45 pm

The raspberry pi was equiped with a rgb led matrix hat with an rtc module also from Adafruit and that works. But I need the raspberry pi full processing power to do other stuff so I thought it would be a good idea to drive the rgb led matrix panel with an arduino uno with the rgb matrix shield. The Uno will then recieve commands from the raspberry pi so the load is not all on the raspberry pi.

But its still strange that I get the same flickering lights when using the external power supply (which can deliver up to 10 amps so it should be enough).

How can I check if the soldering points are good if I don't see any mistakes at first?

I just tried to drive the led matrix panel with the uno without the shield and nothing lights up. I'm not sure if there is a wrong connection there but I used the Adafruit article for reference to the pins.

Also the 32x32 rgb led matrix panel is also from Adafruit.

Bobberius
 
Posts: 6
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Re: Adafruit rbg matrix shield not working

by Bobberius on Sat Aug 01, 2020 1:13 pm

Hi Dave,

I also have an Arduino Mega laying around so I thought why not try the shield on that.
So I tried it and it gives a different result than with the uno. It is the same code except I changed the pin where it says to use with the Arduino mega.
I uploaded another picture with the different result. It stays bright white when I run the code like that.
Attachments
IMG_20200801_185813.jpg
IMG_20200801_185813.jpg (807.18 KiB) Viewed 31 times

Bobberius
 
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Re: Adafruit rbg matrix shield not working

by dastels on Sat Aug 01, 2020 2:28 pm

You changed the pin both on the shield and in the code?

Dave

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Re: Adafruit rbg matrix shield not working

by Bobberius on Sat Aug 01, 2020 2:35 pm

I only changed the pin in the code. Not on the shield.

Bobberius
 
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Re: Adafruit rbg matrix shield not working

by dastels on Sat Aug 01, 2020 2:38 pm


dastels
 
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Re: Adafruit rbg matrix shield not working

by Bobberius on Sun Aug 02, 2020 9:47 am

Hello Dave,

I tried to drive the rgb led matrix panel with my Arduino Mega without the shield and it works! Still wierd that it won't work with the shield. Thank you for helping me.

Bobberius
 
Posts: 6
Joined: Sat Aug 01, 2020 7:25 am

Please be positive and constructive with your questions and comments.