Very impressive results. Even 3x times faster than the Teensy library written by Paul Stoffregen two years ago. Electrodacus made some nice improvements too last year for the STM32 MCUs. Thanks for this great how-to very well explained. I'm not sure I understood it all yet though. May I ask why did you go for bitbanging instead of using the SPI bus ? Did you benchmark the Core0 CPU load while sending the data to the screen ?
Thanks. My cheaper LCD device has an 8-bit parallel bus, no serial SPI. So that brings the advantage of more wires to move data faster. If you look on the Adafruit web page their original LCD was parallel, then they discontinued that one in favour of a Serial SPI version which they admit is a bit slower. So it is a tradeoff: I need more pins and wires than I would for SPI, but I can get better throughput if I can write all 8 bits at the same time. I didn't look at the CPU usage.
Very impressive results. Even 3x times faster than the Teensy library written by Paul Stoffregen two years ago. Electrodacus made some nice improvements too last year for the STM32 MCUs. Thanks for this great how-to very well explained. I'm not sure I understood it all yet though. May I ask why did you go for bitbanging instead of using the SPI bus ? Did you benchmark the Core0 CPU load while sending the data to the screen ?
Thanks. My cheaper LCD device has an 8-bit parallel bus, no serial SPI. So that brings the advantage of more wires to move data faster. If you look on the Adafruit web page their original LCD was parallel, then they discontinued that one in favour of a Serial SPI version which they admit is a bit slower. So it is a tradeoff: I need more pins and wires than I would for SPI, but I can get better throughput if I can write all 8 bits at the same time. I didn't look at the CPU usage.
Well done