// creates the voltage value from the decimal value
private double DecimalToVoltage(AdcPga pga, int temp, int resolution)
{
double voltage;
switch (pga)
{
case AdcPga.G2P3:
voltage = 6.144;
break;
case AdcPga.G1:
voltage = 4.096;
break;
case AdcPga.G2:
voltage = 2.048;
break;
case AdcPga.G4:
voltage = 1.024;
break;
case AdcPga.G8:
voltage = 0.512;
break;
case AdcPga.G16:
default:
voltage = 0.256;
break;
}
return((double)temp * (voltage / (double)resolution));
}
/// <summary>
/// Get a raw ADC reading
/// </summary>
/// <param name="channel">Channel0 - Channel3</param>
/// <param name="size">Size12Bit, Size14Bit, Size16Bit, Size18Bit</param>
/// <param name="pga">Gain1, Gain2, Gain4, Gain8</param>
/// <param name="reading">value of ADC channel read at size & gain</param>
/// <returns>StatusResults(FT260_STATUS, FT260_CONTROLLER_STATUS)</returns>
public UsbI2C.StatusResults ReadAdc(AdcChannel channel, AdcSize size, AdcPga pga, out uint reading)
{
UsbI2C.StatusResults statusResults;
reading = 0;
byte[] control = { 0 };
// start one-shot conversion on channel @ size and gain...
control[0] = (byte)(0x80 | (((int)channel & 3) << 5 | (((int)size & 3) << 2) | ((int)pga & 3)));
lock (_usbI2C)
{
statusResults = _usbI2C.Write(
_i2cAddress,
UsbI2C.FT260_I2C_FLAG.FT260_I2C_START_AND_STOP,
control,
(uint)control.Length);
}
if (statusResults.HasErrors())
{
return(statusResults);
}
// length of result depends upon size of conversion...
byte[] result;
if (size == AdcSize.Size18Bit)
{
result = new byte[4];
}
else
{
result = new byte[3];
}
// continuously read until conversion complete (/RDY bit = 1)...
do
{
lock (_usbI2C)
{
statusResults = _usbI2C.Read(
_i2cAddress,
UsbI2C.FT260_I2C_FLAG.FT260_I2C_START_AND_STOP,
result,
(uint)result.Length);
}
if (statusResults.HasErrors())
{
return(statusResults);
}
Thread.Sleep(1);
} while ((result[result.Length - 1] & 0x80) == 0x00);
// assemble result depending upon size of conversion...
if (size == AdcSize.Size18Bit)
{
reading = ((uint)(result[0] & 3) << 16) | ((uint)result[1] << 8) | (uint)result[2];
}
else
{
reading = ((uint)result[0] << 8) | (uint)result[1];
}
return(statusResults);
}
