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hzeller / rpi-rgb-led-matrix

Controlling up to three chains of 64x64, 32x32, 16x32 or similar RGB LED displays using Raspberry Pi GPIO
GNU General Public License v2.0
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No output (Adafruit HAT, 64x32) #757

Open ctokun opened 5 years ago

ctokun commented 5 years ago

I have a 64x32 matrix connected through the adafruit HAT and I can't get anything to appear on the screen. I have multiple displays because I was planning on chaining them but none of them seem to work (I am only trying them out one at a time right now). So it seems unlikely that the display is the problem. The power supply that is connected to the HAT is able to power the HAT and the Pi on its own, so that does not seem to be the problem either. This was only for testing - the rest of the time I have the Pi connected to its own supply.

I am running Raspbian Lite and I have disabled audio and confirmed that one-wire protocol is not enabled. I have tried to test the demos and always include --led-gpio-mapping=adafruit-hat and I have tried both --led-rows=32 --led-cols=64 and --led-rows=32 --led-cols=32 --led-chain=2. I have also tried various multiplexing options.

Does anyone have any idea what the problem could be?

ltapilot commented 5 years ago

I am successfully using the 6mm pitch 64x32 panels from Adafruit with the RPi 3B+ and Adafruit hat. I got 4 of these panels working on a chain by setting "--led-rows=32 --led-cols=32 --led-chain=8" I also had to specify the "U" mapper as I folded the panels back on themselves to make a 64x128 display. I am essentially treating the 64x32 panels as TWO 32x32 panels. I haven't set the jumper and disabled sound yet, so I do get a bit of flicker, but I'm confident I can get rid of that with the jumper and hardware PWM mod. Note that I'm using a 5V 4A supply for the Pi and hat and another TWO 5V 10A supplies for the panels. These panels eat current for lunch; that's how they can get so bright (and subsequently blister your retina). In some instances a moderately large, fast capacitor should be soldered right next to the connector on the panels to prevent fast switching transients from causing problems. I hope this helps.

patrickhirsh commented 5 years ago

There's a chance that you have a HUB75E connector instead of a HUB75 on your panel. I ran into the same issue and didn't even notice because they look identical. If that's the case, take a look at shades66's script halfway down this thread: https://github.com/hzeller/rpi-rgb-led-matrix/issues/746