#include #include #include #include #include #include #include #include #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; }