private async Task ReadSensorAsync()
{
GalaSoft.MvvmLight.Threading.DispatcherHelper.CheckBeginInvokeOnUI(async() =>
{
DateTime ReadingTime = DateTime.Now;
//Get PhotoResistor
byte[] readBuffer = new byte[3]; /* Buffer to hold read data*/
byte[] writeBuffer = new byte[3] {
StartByte, Channel0, 0x00
};
SpiADC.TransferFullDuplex(writeBuffer, readBuffer); /* Read data from the ADC */
Light = convertToInt(readBuffer); /* Convert the returned bytes into an integer value */
//Get Temperature
readBuffer = new byte[3]; /* Buffer to hold read data*/
writeBuffer = new byte[3] {
StartByte, Channel1, 0x00
};
SpiADC.TransferFullDuplex(writeBuffer, readBuffer); /* Read data from the ADC */
int adcTemp = convertToInt(readBuffer); /* Convert the returned bytes into an integer value */
// millivolts = value * (volts in millivolts / ADC steps)
double millivolts = adcTemp * (3300.0 / 1024.0);
Temperature = (millivolts - 500) / 10.0; //given equation from sensor documentation
if (Temperature > AlertTemperature)
{
string m = string.Format("Temperature {0} exceeds Alert Temperature {1}", Temperature, AlertTemperature);
Alert alertMsg = new Alert {
AlertMsg = m
};
//turn on alert LED, only way to clear it is IoT Central Command)
ledAlertValue = GpioPinValue.High;
ledAlert.Write(ledAlertValue);
Alert = redBrush;
}
Reading reading = new Reading
{
ReadingDateTime = ReadingTime,
Temperature = Temperature,
Light = Light,
Control = ledControlValue == GpioPinValue.High ? true : false
};
//limit the amount of data we are charting
while (Readings.Count > 60)
{
Readings.RemoveAt(0);
}
Readings.Add(reading);
});
}
private void _sensor_ReadingComplete(object sender, ReadingArgs e)
{
DispatcherHelper.CheckBeginInvokeOnUI(() =>
{
ReadingDateTime = e.ReadingTime;
PM1_0Concentration_CF1 = _sensor.PM1_0Concentration_CF1;
PM2_5Concentration_CF1 = _sensor.PM2_5Concentration_CF1;
PM10_0Concentration_CF1 = _sensor.PM10_0Concentration_CF1;
PM1_0Concentration_amb = _sensor.PM1_0Concentration_amb;
PM2_5Concentration_amb = _sensor.PM2_5Concentration_amb;
PM10_0Concentration_amb = _sensor.PM10_0Concentration_amb;
PM0_3Count = _sensor.PM0_3Count;
PM0_5Count = _sensor.PM0_5Count;
PM1_0Count = _sensor.PM1_0Count;
PM5_0Count = _sensor.PM5_0Count;
PM10_0Count = _sensor.PM10_0Count;
ProductVersion = _sensor.ProductVersion;
ErrorCodes = _sensor.StatusCodes;
while (Readings.Count > GraphReadings)
{
Readings.RemoveAt(0);
}
Reading reading = new Reading
{
PM1_0Concentration = PM10_0Concentration_CF1,
PM2_5Concentration = PM2_5Concentration_CF1,
PM10_0Concentration = PM10_0Concentration_CF1,
ReadingDateTime = ReadingDateTime
};
Readings.Add(reading);
while (CountsLow.Count > GraphReadings)
{
CountsLow.RemoveAt(0);
}
CountsLow countsLow = new CountsLow
{
PM2_5Count = PM2_5Count,
PM5_0Count = PM5_0Count,
PM10_0Count = PM10_0Count,
ReadingDateTime = ReadingDateTime
};
CountsLow.Add(countsLow);
while (CountsHigh.Count > GraphReadings)
{
CountsHigh.RemoveAt(0);
}
CountsHigh countsHigh = new CountsHigh
{
PM1_0Count = PM1_0Count,
PM0_5Count = PM0_5Count,
PM0_3Count = PM0_3Count,
ReadingDateTime = ReadingDateTime
};
CountsHigh.Add(countsHigh);
});
}