in ev3-api/src/ev3api_sensor.c [464:481]
bool_t ht_nxt_color_sensor_measure_color(sensor_port_t port, uint8_t *color) {
ER ercd;
CHECK_PORT(port);
CHECK_COND(ev3_sensor_get_type(port) == HT_NXT_COLOR_SENSOR, E_OBJ);
CHECK_COND(*pI2CSensorData[port].status == I2C_TRANS_IDLE, E_OBJ);
*color = pI2CSensorData[port].raw[0];
ercd = start_i2c_transaction(port, 0x1, "\x42", 1, 1);
assert(ercd == E_OK);
return true;
error_exit:
syslog(LOG_WARNING, "%s(): ercd %d", __FUNCTION__, ercd);
return false;
}