spi test

uint8_t *txbuf;
uint8_t *rxbuf;

void setup(void){
    static uint8_t _txbuf[8] __attribute__ ((section (".sram2")));
    static uint8_t _rxbuf[8] __attribute__ ((section (".sram2")));
    txbuf = _txbuf;
    rxbuf = _rxbuf;

    palSetPadMode(GPIOA,3,PAL_MODE_OUTPUT_PUSHPULL);    //POT
    palWritePad(GPIOA,3,1);
    palSetPadMode(GPIOA,2,PAL_MODE_OUTPUT_PUSHPULL);    //CV
    palWritePad(GPIOA,2,1);


}


void loop(void){

    // first SPI block
    txbuf[0] = 0xE0;
    txbuf[1] = 0xFF;
    txbuf[2] = 0x00;
    txbuf[3] = 0x00;
    txbuf[4] = 0x00;
    txbuf[5] = 0x00;
    txbuf[6] = 0xFF;

    //spiAcquireBus(&SPID1);

    palWritePad(GPIOA,3,0);
    spiSelect(&SPID1);      // START SPI
    //spiSend(&SPID1,4,txbuf);
    //spiReceive(&SPID1,4,rxbuf);
    spiExchange(&SPID1, 6, txbuf, rxbuf);
    spiUnselect(&SPID1);
    palWritePad(GPIOA,3,1);

    //spiReleaseBus(&SPID1);

    int z = (rxbuf[4] << 16| rxbuf[3] << 8| rxbuf[2] ) << 8;

    chThdSleep(1);
    //chThdSleepMilliseconds(1);

    // secound SPI block
    txbuf[0]= 0b01111111;

    spiSelect(&SPID1);
    palWritePad(GPIOA,2,0);
    //spiSend(&SPID1, 1, txbuf);
    spiExchange(&SPID1, 1, txbuf, rxbuf);

    spiUnselect(&SPID1);
    palWritePad(GPIOA,2,1);

    chThdSleep(1);
    // third SPI block

    txbuf[0]= 0b01111111;

    spiSelect(&SPID1);
    palWritePad(GPIOA,2,0);
    spiSend(&SPID1, 1, txbuf);
    //spiExchange(&SPID1, 1, txbuf, rxbuf);
    spiUnselect(&SPID1);
    palWritePad(GPIOA,2,1);

    chThdSleep(1);
    //chThdSleepMilliseconds(1);
    }