/****************************************************************************
*
* NAME: vProcessRead
*
* DESCRIPTION:
* Gets the current readings from each sensor. If the light level causes the
* low light alarm to be triggered, an LED is illuminated.
*
* RETURNS:
* void
*
* NOTES:
* This is not an efficient way to read the sensors as much time is wasted
* waiting for the humidity and temperature sensor to complete. The sensor
* pulls a DIO line low when it is ready, and this could be used to generate
* an interrupt to indicate when data is ready to be read.
*
****************************************************************************/
PRIVATE void vProcessRead(void)
{
uint16 u16LightSensor;
uint16 u16Diff;
/* Read light level, adjust to range 0-6. This sensor automatically starts
a new conversion afterwards so there is no need for a 'start read' */
u16LightSensor = u16ALSreadChannelResult();
/* Adjust the high and low values if necessary, and obtain the
difference between them */
if (sDemoData.sLightSensor.u16Hi < u16LightSensor)
{
sDemoData.sLightSensor.u16Hi = u16LightSensor;
}
if (sDemoData.sLightSensor.u16Lo > u16LightSensor)
{
sDemoData.sLightSensor.u16Lo = u16LightSensor;
}
u16Diff = sDemoData.sLightSensor.u16Hi - sDemoData.sLightSensor.u16Lo;
/* Work out the current value as a value between 0 and 6 within the
range of values that have been seen previously */
if (u16Diff)
{
sDemoData.sSensors.u8AlsResult = (uint8)(((uint32)(u16LightSensor - sDemoData.sLightSensor.u16Lo) * 6) / (uint32)u16Diff);
}
else
{
sDemoData.sSensors.u8AlsResult = 3;
}
/* Set LED 1 based on light level */
if ((sDemoData.sSensors.u8AlsResult <= sDemoData.sControls.u8LightAlarmLevel)
&& (sDemoData.sControls.u8LightAlarmLevel < 7))
{
vLedControl(LED2, TRUE);
}
else
{
vLedControl(LED2, FALSE);
}
/* Read temperature, 0-52 are acceptable. Polls until result received */
vHTSstartReadTemp();
sDemoData.sSensors.u8TempResult = u8FindMin((uint8)u16HTSreadTempResult(), 52);
/* Read humidity, 0-104 are acceptable. Polls until result received */
vHTSstartReadHumidity();
sDemoData.sSensors.u8HtsResult = u8FindMin((uint8)u16HTSreadHumidityResult(), 104);
}
/****************************************************************************
*
* NAME: vReadTempHumidity
*
* DESCRIPTION:
*
* Read temperature/humidity sensor. Reading is performed using a state machine
* to ensure that it never blocks.
*
****************************************************************************/
PRIVATE void vReadTempHumidity(void)
{
switch(sTempHumiditySensor.eState)
{
case E_STATE_READ_TEMP_HUMID_IDLE:
vHTSstartReadHumidity();
sTempHumiditySensor.eState = E_STATE_READ_HUMID_RUNNING;
break;
case E_STATE_READ_HUMID_RUNNING:
if ((u32AHI_DioReadInput() & HTS_DATA_DIO_BIT_MASK) == 0)
{
sTempHumiditySensor.eState = E_STATE_READ_TEMP_HUMID_COMPLETE;
}
break;
case E_STATE_READ_TEMP_HUMID_COMPLETE:
sTempHumiditySensor.u16HumidReading = u16HTSreadHumidityResult();
sTempHumiditySensor.eState = E_STATE_READ_TEMP_START;
break;
case E_STATE_READ_TEMP_START:
vHTSstartReadTemp();
sTempHumiditySensor.eState = E_STATE_READ_TEMP_HUMID_RUNNING;
break;
case E_STATE_READ_TEMP_HUMID_RUNNING:
if ((u32AHI_DioReadInput() & HTS_DATA_DIO_BIT_MASK) == 0)
{
sTempHumiditySensor.eState = E_STATE_READ_TEMP_COMPLETE;
}
break;
case E_STATE_READ_TEMP_COMPLETE:
sTempHumiditySensor.u16TempReading = u16HTSreadTempResult();
sTempHumiditySensor.eState = E_STATE_READ_TEMP_HUMID_READY;
break;
case E_STATE_READ_TEMP_HUMID_READY:
break;
default:
break;
}
}
/* Process to get ht sensor value.
ht sensor is sampled. Sampling stopped when sensor is de-activated.
Event is generated if temp and/or hum value changed at least the value DELTA_TEMP_SENSOR_VALUE
or DELTA_HUM_SENSOR_VALUE since last event. */
PROCESS_THREAD(HTSensorSampling, ev, data)
{
PROCESS_BEGIN();
static struct etimer et;
etimer_set(&et, CLOCK_SECOND);
while(1) {
PROCESS_WAIT_EVENT_UNTIL((ev == PROCESS_EVENT_TIMER) || (ev == PROCESS_EVENT_MSG));
if(ev == PROCESS_EVENT_TIMER) {
/* Handle sensor reading. */
vHTSstartReadTemp();
temp_sensor_value = u16HTSreadTempResult();
PRINTF("Temperature sample: %d\n", temp_sensor_value);
vHTSstartReadHumidity();
hum_sensor_value = u16HTSreadHumidityResult();
PRINTF("Humidity sample: %d\n", hum_sensor_value);
if((abs(temp_sensor_value - prev_temp_event_val) > DELTA_TEMP_SENSOR_VALUE) ||
(abs(hum_sensor_value - prev_hum_event_val) > DELTA_HUM_SENSOR_VALUE)) {
prev_temp_event_val = temp_sensor_value;
prev_hum_event_val = hum_sensor_value;
sensors_changed(&ht_sensor);
}
etimer_reset(&et);
} else {
/* ev == PROCESS_EVENT_MSG */
if(*(int *)data == HT_SENSOR_STATUS_NOT_ACTIVE) {
/* Stop sampling */
etimer_stop(&et);
} else if((*(int *)data == HT_SENSOR_STATUS_ACTIVE)) {
/* restart sampling */
etimer_restart(&et);
}
}
}
PROCESS_END();
}
