acc.c

static void start_accelerometer() {
	sensor_type_e type = SENSOR_ACCELEROMETER;
	int max_batch_latency = 30000; // 300 is max queue, 100 ms is default period

	if (sensor_get_default_sensor(type, &sensor) == SENSOR_ERROR_NONE)
	{
	    if (sensor_create_listener(sensor, &listener) == SENSOR_ERROR_NONE
			&& sensor_listener_set_max_batch_latency(listener, max_batch_latency) == SENSOR_ERROR_NONE
	        && sensor_listener_set_event_cb(listener, 100, accelerometer_sensor_event_callback, NULL) == SENSOR_ERROR_NONE
	    	&& sensor_listener_set_option(listener, SENSOR_OPTION_ALWAYS_ON) == SENSOR_ERROR_NONE
			)
	    {
	        if (sensor_listener_start(listener) == SENSOR_ERROR_NONE)
	        {
	        	dlog_print(DLOG_INFO, TAG, "Sensor started");
	        }
	    }
	}
}