ESP8266 Community Forum

- Mon May 11, 2020 3:51 pm #87047 Hi,
I was looking for a way to send SPI data almost continuously without blocking the CPU. I usually use PlatformIO / Arduino SDK for developing and its SPI class only supports blocking writes for SPI. I also couldn't find any usable code in the RTOS SDK. So I wrote my own:
https://github.com/xsrf/nbSPI

Basically, it fills the SPI buffer with up to 64 Bytes of data and sends it. If more data must be sent, it enables the TRANSMISSION_END Interrupt and uses it to refill the buffer.

I'd appreciate your thoughts about this

I'm not at all sure if I'm handling the interrupts correct. As far as I did understand, interrupts for SPI1 and SPI0 trigger the same ISR.
I'm actually ignoring and clearing Interrupts for SPI0. Could this cause problems? So far it works...

See https://github.com/xsrf/nbSPI/issues/1

Code: Select allICACHE_RAM_ATTR void nbSPI_ISR() {
    if(SPIIR & (1 << SPII0)) {
        // SPI0 Interrupt
        SPI0S &= ~(0x1F); // Disable and clear all interrupts on SPI0
    }
    if(SPIIR & (1 << SPII1)) {
        // SPI1 Interrupt
        SPI1S &= ~(0x1F); // Disable and clear all interrupts on SPI1
        nbSPI_writeChunk(); // Write remaining data
    }
}

- Sun May 31, 2020 7:11 am #87350 What happens if you don't clear the SPI0 interrupt? Because I don't think that should be done.