bme680/i2c.c

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1.3 KiB
C
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2023-09-17 20:31:02 +00:00
#include <stdio.h>
#include <fcntl.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <stdlib.h>
#define MY_DEVICE "/dev/i2c-1"
#define MY_DEVICE_ADDRESS 0x77
int i2c_init(const char *dev, uint8_t addr) {
int fd = -1;
fd = open(dev, O_RDWR);
if (fd < 0) {
fprintf(stderr, "could not open device: %s\n", dev);
return -1;
}
if (ioctl(fd, I2C_SLAVE, addr) < 0) {
fprintf(stderr, "failed to acquire bus/talk to slave\n");
close(fd);
return -1;
}
return fd;
}
int i2c_read_reg(int fd, uint8_t reg, uint8_t length, uint8_t *buf) {
uint8_t cmd[2] = {reg, 0x00};
write(fd, cmd, 2);
if (read(fd, buf, length) != length) {
fprintf(stderr, "error read()\n");
return 1;
}
return 0;
}
uint8_t i2c_read_reg2(int fd, uint8_t reg) {
uint8_t buf;
i2c_read_reg(fd, reg, 1, &buf);
return buf;
}
int i2c_write_reg(int fd, uint8_t reg, uint8_t value) {
uint8_t cmd[2] = {reg, value};
if (write(fd, cmd, 2) != 2) {
fprintf(stderr, "error write()\n");
return 1;
}
return 0;
}
int main2(void) {
int res;
uint8_t cmd_buf[2] = {0x00, 0x00};
int fd = i2c_init(MY_DEVICE, MY_DEVICE_ADDRESS);
if (i2c_read_reg(fd, 0xD0, 1, (uint8_t *)&res) != 0) {
fprintf(stderr, "ddd\n");
}
printf("%X\n", res);
printf("%X\n", i2c_read_reg2(fd, 0xD0));
close(fd);
return 0;
}