General • Re: Trying to use Pimoroni display with Pico 2 & Arduino Software

This is how Pimoroni issues the commands in their C++ driver: https://github.com/pimoroni/pimoroni-pi ... st7789.cpp
It should be clear that it uses DC signal
(4-lines serial interface use: CSX (chip enable), D/CX (data/ command flag), SCL (serial clock) and SDA (serial data input/output))
mode which is well supported by ST7789V.

P.S. BTW for serial interface they use SPI+DMA for data and clock, the rest is driven in software through SIO, and a little bit of overclocking

// The ST7789 requires 16 ns between SPI rising edges.
// 16 ns = 62,500,000 Hz
// 2350 doesn't support 62,500,000 so use 75,000,000 seems to work.

Code:

void ST7789::command(uint8_t command, size_t len, const char *data) {    gpio_put(dc, 0); // command mode    gpio_put(cs, 0);       if(spi) {      spi_write_blocking(spi, &command, 1);    } else {      write_blocking_parallel(&command, 1);    }    if(data) {      gpio_put(dc, 1); // data mode      if(spi) {        spi_write_blocking(spi, (const uint8_t*)data, len);      } else {        write_blocking_parallel((const uint8_t*)data, len);      }    }    gpio_put(cs, 1);  }

Statistics: Posted by gmx — Sun Nov 16, 2025 2:06 am

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