private uint GetRawPressure()
{
WriteByte(Interop.CONTROL, (byte)(Interop.READPRESSURECMD + ((int)precision << 6)));
switch (precision)
{
case Bmp085Precision.Low:
HighResolutionTimer.Sleep(lowDelay);
break;
case Bmp085Precision.High:
HighResolutionTimer.Sleep(highDelay);
break;
case Bmp085Precision.Highest:
HighResolutionTimer.Sleep(highestDelay);
break;
default:
HighResolutionTimer.Sleep(defaultDelay);
break;
}
var msb = ReadByte(Interop.PRESSUREDATA);
var lsb = ReadByte(Interop.PRESSUREDATA + 1);
var xlsb = ReadByte(Interop.PRESSUREDATA + 2);
var raw = ((msb << 16) + (lsb << 8) + xlsb) >> (8 - (int)precision);
return((uint)raw);
}
private ushort GetRawTemperature()
{
WriteByte(Interop.CONTROL, Interop.READTEMPCMD);
HighResolutionTimer.Sleep(lowDelay);
return(ReadUInt16(Interop.TEMPDATA));
}
private void SendByte(byte data)
{
// Send one bit at a time, starting with the MSB
for (byte i = 0; i < 8; i++)
{
// If MSB is 1, write one and clock it, else write 0 and clock
if ((data & 0x80) != 0)
{
dataPin.Write(true);
}
else
{
dataPin.Write(false);
}
// clk():
clockPin.Write(false);
HighResolutionTimer.Sleep(0.02m);
clockPin.Write(true);
HighResolutionTimer.Sleep(0.02m);
// Advance to the next bit to send
data <<= 1;
}
}
private void LatchData()
{
dataPin.Write(false);
HighResolutionTimer.Sleep(delay);
for (int i = 0; i < 4; i++)
{
dataPin.Write(true);
dataPin.Write(false);
}
}
/// <summary>
/// Senses the distance.
/// </summary>
public void SenseDistance()
{
var timer = new HighResolutionTimer();
this.EnsureReady();
_timer = new Stopwatch();
_trigPin.Write(GpioPinValue.High);
timer.Sleep(0.01d);
_trigPin.Write(GpioPinValue.Low);
}
/// <summary>
/// Sets the pin resistor.
/// </summary>
/// <param name="pin">The pin.</param>
/// <param name="resistor">The resistor.</param>
public void SetPinResistor(ProcessorPin pin, PinResistor resistor)
{
// Set the pullup/down resistor for a pin
//
// The GPIO Pull-up/down Clock Registers control the actuation of internal pull-downs on
// the respective GPIO pins. These registers must be used in conjunction with the GPPUD
// register to effect GPIO Pull-up/down changes. The following sequence of events is
// required:
// 1. Write to GPPUD to set the required control signal (i.e. Pull-up or Pull-Down or neither
// to remove the current Pull-up/down)
// 2. Wait 150 cycles ? this provides the required set-up time for the control signal
// 3. Write to GPPUDCLK0/1 to clock the control signal into the GPIO pads you wish to
// modify ? NOTE only the pads which receive a clock will be modified, all others will
// retain their previous state.
// 4. Wait 150 cycles ? this provides the required hold time for the control signal
// 5. Write to GPPUD to remove the control signal
// 6. Write to GPPUDCLK0/1 to remove the clock
//
// RPi has P1-03 and P1-05 with 1k8 pullup resistor
uint pud;
switch (resistor)
{
case PinResistor.None:
pud = Interop.BCM2835_GPIO_PUD_OFF;
break;
case PinResistor.PullDown:
pud = Interop.BCM2835_GPIO_PUD_DOWN;
break;
case PinResistor.PullUp:
pud = Interop.BCM2835_GPIO_PUD_UP;
break;
default:
throw new ArgumentOutOfRangeException("resistor", resistor, string.Format(CultureInfo.InvariantCulture, "{0} is not a valid value for pin resistor", resistor));
}
WriteResistor(pud);
HighResolutionTimer.Sleep(resistorSetDelay);
SetPinResistorClock(pin, true);
HighResolutionTimer.Sleep(resistorSetDelay);
WriteResistor(Interop.BCM2835_GPIO_PUD_OFF);
SetPinResistorClock(pin, false);
pinResistors[pin] = PinResistor.None;
}
public double GetData()
{
Connection.Write(0x10);
HighResolutionTimer.Sleep(TimeSpanUtility.FromMicroseconds(150 * 1000));
byte[] readBuf = Connection.Read(2);
var valf = readBuf[0] << 8;
valf |= readBuf[1];
return(valf / 1.2 * (69 / 69) / 1);
// var valf = ((readBuf[0] << 8) | readBuf[1]) / 1.2;
// return valf;
// return Math.Round(valf / (2 * 1.2), 2);
}
private DhtData TryGetData()
{
// Prepare buffer
var data = new byte[5];
for (var i = 0; i < 5; i++)
{
data[i] = 0;
}
var remainingSamplingInterval = SamplingInterval - (DateTime.UtcNow - previousRead);
if (remainingSamplingInterval > TimeSpan.Zero)
{
HighResolutionTimer.Sleep((int)remainingSamplingInterval.TotalMilliseconds);
}
// Prepare for reading
try
{
// Measure required by host : pull down then pull up
pin.Write(false);
HighResolutionTimer.Sleep((decimal)WakeupInterval.TotalMilliseconds);
pin.Write(true);
// Read acknowledgement from DHT
pin.Wait(true, timeout);
pin.Wait(false, timeout);
// Read 40 bits output, or time-out
var cnt = 7;
var idx = 0;
for (var i = 0; i < 40; i++)
{
pin.Wait(true, timeout);
var start = DateTime.UtcNow;
pin.Wait(false, timeout);
// Determine whether bit is "1" or "0"
if (DateTime.UtcNow - start > bitSetUptime)
{
data[idx] |= (byte)(1 << cnt);
}
if (cnt == 0)
{
idx++; // next byte
cnt = 7; // restart at MSB
}
else
{
cnt--;
}
}
}
finally
{
// Prepare for next reading
previousRead = DateTime.UtcNow;
pin.Write(true);
}
var checkSum = data[0] + data[1] + data[2] + data[3];
if ((checkSum & 0xff) != data[4])
{
throw new InvalidChecksumException("Invalid checksum on DHT data", data[4], (checkSum & 0xff));
}
var sign = 1;
if ((data[2] & 0x80) != 0) // negative temperature
{
data[2] = (byte)(data[2] & 0x7F);
sign = -1;
}
var humidity = (data[0] << 8) + data[1];
var temperature = sign * ((data[2] << 8) + data[3]);
return(GetDhtData(temperature, humidity));
}