Question

所以我很难设置我的SPI，并让它与LSM330设备一起工作以读取加速度计数据。我只是设置SPI系统，并尝试使用它来读取WHO_AM_I_A寄存器以确认它正在工作，而我所得到的只是0xff而不是0x40。

这是我的代码：

的main.c

#include <avr/io.h>
#include "LSM330.h"
#include "spi.h"
#include "CLK.h"
#include "accel.h"

int main(void) {
    //set clock
    set32MhzClock();

    //first set SPI slave selects for accel gyro to false(high)
    PORTF.OUTSET = PIN4_bm | PIN3_bm;

    //set serial system of SPI
    PORTA_OUTCLR = PIN4_bm;

    //init SPI
    spi_init();

    //reset LSM330 accel by sending 0x01 to CTRL_REG4_A
    accel_write(0x01, CTRL_REG4_A);

    //trying to read from WHO_AM_I_A reg
    uint8_t whoAreYou = accel_read(WHO_AM_I_A);
    printf(whoAreYou);
}

accel.h

#include "LSM330.h"
#include "spi.h"

void accel_write(uint8_t reg_addr, uint8_t data) {
    //make slave select signal LOW
    PORTF_OUTCLR = PIN3_bm;

    //set sensor_sel
    PORTF_OUTSET = PIN2_bm;

    //first write reg_addr, w/ RW=0 and MS=0
    uint8_t writeResult = spi_write(reg_addr);

    //then write data byte
    spi_write(data);

    return;
}

spi.h中

void spi_init(void) {
    //set correct pins as outputs and inputs
    PORTF.DIRSET = PIN7_bm | PIN5_bm | PIN4_bm | PIN3_bm; //SCK, MOSI, SSG, SSA as outputs
    PORTF.DIRCLR = PIN6_bm; //MISO as input

    //set up SPI as master
    SPIF.CTRL = SPI_ENABLE_bm | SPI_MASTER_bm | SPI_MODE_3_gc | SPI_PRESCALER_DIV16_gc;

   //clear spi interrupt flag by reading spsr and spdr
   SPIF_STATUS;
   SPIF_DATA;

   return
}

uint8_t spi_write(uint8_t dataIn) {
    //write data
    SPIF.DATA = dataIn;

    //wait for transmission to complete
    while(!(SPIF_STATUS & SPI_IF_bm));
    return SPIF.DATA;
}

uint8_t spi_read(vodi) {
    return spi_write(0xFF);
}

这就是我的全部。尝试了很多东西，似乎无法让这件事情发挥作用。似乎SPI正在工作，因为它在写入数据时不会陷入任何while循环中。

Answer 1

没有太多细节，这里肯定有问题：

//reset LSM330 accel by sending 0x01 to CTRL_REG4_A
accel_write(0x01, CTRL_REG4_A);

但是你的功能声明如下：

void accel_write(uint8_t reg_addr, uint8_t data)

您似乎将寄存器0x01设置为CTRL_REG4_A的值。

XMEGA设置SPI并从LSM330设备读取WHO_AM_I_A寄存器

1 个答案: