File SpiDmaTransmit.cpp

File List > examples > SPI > SpiDmaTransmit > SpiDmaTransmit.cpp

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Source Code

#include "daisy_patch_sm.h"

using namespace daisy;
using namespace patch_sm;

DaisyPatchSM hw;

// put these four bytes in a buffer. It has to be in a special memory section to be used with DMA
uint8_t DMA_BUFFER_MEM_SECTION buffer[4] = {0, 1, 2, 3};

int main(void)
{
    // Initialize the hardware
    hw.Init();

    // Handle we'll use to interact with SPI
    SpiHandle spi_handle;

    // Structure to configure the SPI handle
    SpiHandle::Config spi_conf;

    spi_conf.mode = SpiHandle::Config::Mode::MASTER; // we're in charge

    spi_conf.periph = SpiHandle::Config::Peripheral::SPI_2; // Use the SPI_2 Peripheral

    // Pins to use. These must be available on the selected peripheral
    spi_conf.pin_config.sclk = DaisyPatchSM::D10; // Use pin D10 as SCLK
    spi_conf.pin_config.miso = Pin(); // We won't need this
    spi_conf.pin_config.mosi = DaisyPatchSM::D9; // Use D9 as MOSI
    spi_conf.pin_config.nss = DaisyPatchSM::D1; // use D1 as NSS

    // data will flow from master to slave over just the MOSI line
    spi_conf.direction = SpiHandle::Config::Direction::TWO_LINES_TX_ONLY;

    // The master will output on the NSS line
    spi_conf.nss = SpiHandle::Config::NSS::HARD_OUTPUT;

    // Initialize the SPI Handle
    spi_handle.Init(spi_conf);

    // loop forever
    while(1) 
    {
        // Use DMA to Transmit those 4 bytes. We don't have to wait for this to complete, we could go on and do other things here
        // We won't use the callback or callback data features either, so we'll set them to NULL
        spi_handle.DmaTransmit(buffer, 4, NULL, NULL, NULL);

        // wait 500 ms
        System::Delay(500);
    }
}