lib/spi_sw.c


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#include "spi_sw.h"
#include <libopencm3/stm32/gpio.h>
#include <stdint.h>

SPI_IMPL SpiInit(uint16_t MOSI_pin, uint16_t CLK_pin) {
    SPI_IMPL outp = {
        .MOSI_pin = MOSI_pin,
        .CLK_pin = CLK_pin,
        .delay = (uint16_t) 1000,
    };
    return outp;
}

void SpiSend(SPI_IMPL *spi, uint8_t playload) {
    if (TRAILING_EDGE) {
        gpio_clear(GPIOA, spi->CLK_pin);
    } else {
        gpio_set(GPIOA, spi->CLK_pin);
    }

    for (int i = 0; i < 8; i++) {
        gpio_toggle(GPIOA, spi->CLK_pin);
        if ((playload >> i) & 1) {
            gpio_clear(GPIOA, spi->MOSI_pin);
        } else {
            gpio_set(GPIOA, spi->MOSI_pin);
        }
        delayCycles(spi->delay);
        gpio_toggle(GPIOA, spi->CLK_pin);
        delayCycles(spi->delay);
    }
}