user_adc_read.c

Paper_Love2026-04-17 15:01

程序

复制代码

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>

#define SYSFS_IIO_PATH "/sys/bus/iio/devices/iio:device0"

int read_adc_raw(int channel)
{
    char path[256];
    char buf[32];
    int fd, ret;
    int value;

    // 构造路径，例如 /sys/bus/iio/devices/iio:device0/in_voltage0_raw
    snprintf(path, sizeof(path), "%s/in_voltage%d_raw", SYSFS_IIO_PATH, channel);

    fd = open(path, O_RDONLY);
    if (fd < 0) {
        fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
        return -1;
    }

    ret = read(fd, buf, sizeof(buf) - 1);
    if (ret < 0) {
        fprintf(stderr, "Failed to read %s: %s\n", path, strerror(errno));
        close(fd);
        return -1;
    }
    buf[ret] = '\0';
    close(fd);

    value = atoi(buf);
    return value;
}

int main(int argc, char *argv[])
{
    int channel = 0;  // 默认通道0
    int raw_value;

    if (argc > 1)
        channel = atoi(argv[1]);

    raw_value = read_adc_raw(channel);
    if (raw_value < 0) {
        fprintf(stderr, "Read ADC channel %d failed\n", channel);
        return 1;
    }

    printf("ADC channel %d raw value: %d\n", channel, raw_value);
    return 0;
}

编译与运行

复制代码

gcc -o user_adc_read user_adc_read.c
./user_adc_read 0      # 读取通道0的原始值