First time using timer-triggered chained DMAs, where one DMA channel writes into the descriptors of another DMA channel to change what the other DMA is doing. This is just a 8x9 matrix array in a 6x12 configuration on a ch32v003, with #ch32fun https://github.com/cnlohr/cnhardware/blob/master/ch32v003/ledarray-badgetest/firmware/firmware.c#L84-L119