Raspberry PI 3B+ powered LED matrix with the same resolution as the c-base matelight with 16x40 LEDs. Fun fact, when you buy a ten pack of 8x8 matrices, you get the same amount of LEDs = 640 of them.

We had an event with short talks at the xHain Hackerspace recently and we wanted to use the club matrix as a timer for the presenter. I have yet to write a font generator and a script to do that though and the only thing I can kind of reliably do is playing a video. The sane solution: search on youtube for a 15min countdown video, which kind of worked.

But since we were at the hackerspace, one member wanted to try to let ffmpeg generate the countdown. The first version of the script by Niklas was almost perfect, but used a PNG as a background image. Then another member (danimo) took a look and removed the background image and let ffmpeg turn the background from green to red in the last minute.

When I finally found the error in this function, I had already written a lookup table for all the 640 LEDs. This is fixed for my setup, but it should be possible to rearrange it for others.

int matrix_arrangement[] = { 0,1,2,3,4,9,8,7,6,5 };
voidclub_matrix_render(void)
{
for (int i=0; i<led_count; i++)
{
int led_real_x = i % width; // 0 to 39int led_real_y = i / width; // 0 to 1int matrix_number_x = led_real_x / 8; // should be 0 to 4int matrix_number_y = led_real_y / 8; // should be 0 or 1int matrix_number = matrix_number_y * 5 + matrix_number_x; // 0 to 9int matrix_x = led_real_x % 8; // 0 to 7int matrix_y = led_real_y % 8; // 0 to 7
ledstring.channel[0].leds[matrix_arrangement[matrix_number] * 64 + matrix_y * 8 + matrix_x] = matrix[i];
}
}

Hi! Thanks, I think the way the Neopixel matrices talk and are arranged are quite different though. I'm sitting here at the chaos communication congress and was successfully sending UDP packets to it.

Would love to show you how to put FlashLex on this. I have a very similar project that you could probably use to show you how. https://hackaday.io/project/168952-raspberry-pi-3-iot-32x32-led-matrix