private int GetDistance()
{
// First we need to pulse the port from high to low.
_port.Active = true; // Put port in write mode
_port.Write(true); // Pulse pin
_port.Write(false);
_port.Active = false; // Put port in read mode;
var lineState = false;
// Wait for the line to go high, for start of pulse.
while (lineState == false)
{
lineState = _port.Read();
}
var startOfPulseAt = DateTime.Now.Ticks; // Save start ticks.
// Wait for line to go low.
while (lineState)
{
lineState = _port.Read();
}
var endOfPulse = DateTime.Now.Ticks; // Save end ticks.
var ticks = (int)(endOfPulse - startOfPulseAt);
return(ticks / 580);
}
/// <summary>
/// Retrieves measured data from the sensor.
/// </summary>
/// <returns>
/// <c>true</c> if the operation succeeds and the data is valid, otherwise <c>false</c>.
/// </returns>
public bool Read()
{
if (disposed)
{
throw new ObjectDisposedException();
}
// The 'bitMask' also serves as edge counter: data bit edges plus
// extra ones at the beginning of the communication (presence pulse).
bitMask = 1L << 41;
data = 0;
// lastTicks = 0; // This is not really needed, we measure duration
// between edges and the first three values are ignored anyway.
// Initiate communication
portOut.Active = true;
portOut.Write(false); // Pull bus low
Thread.Sleep(StartDelay);
portIn.EnableInterrupt(); // Turn on the receiver
portOut.Active = false; // Release bus
bool dataValid = false;
// Now the interrupt handler is getting called on each falling edge.
// The communication takes up to 5 ms, but the interrupt handler managed
// code takes longer to execute than is the duration of sensor pulse
// (interrupts are queued), so we must wait for the last one to finish
// and signal completion. 20 ms should be enough, 50 ms is safe.
if (dataReceived.WaitOne(50, false))
{
// TODO: Use two short-s ?
bytes[0] = (byte)((data >> 32) & 0xFF);
bytes[1] = (byte)((data >> 24) & 0xFF);
bytes[2] = (byte)((data >> 16) & 0xFF);
bytes[3] = (byte)((data >> 8) & 0xFF);
byte checksum = (byte)(bytes[0] + bytes[1] + bytes[2] + bytes[3]);
if (checksum == (byte)(data & 0xFF))
{
dataValid = true;
Convert(bytes);
}
else
{
Debug.Print("DHT sensor data has invalid checksum.");
}
}
else
{
portIn.DisableInterrupt(); // Stop receiver
Debug.Print("DHT sensor data timeout."); // TODO: TimeoutException?
}
return(dataValid);
}
public long ReadRightIR()
{
// Turn on IR LEDs (optional)
LEDIREmmitter.Write(true);
// Make the I/O line connected to that sensor an output and drive it high
RightIR.Active = true; // Set to output pin
RightIR.Write(true); // Set pin to high to charge capacitor
// Wait several microseconds to give the 1 nF capacitor node time to reach 5 V
Thread.Sleep(5); // Wait about 10 milliseconds to allow capacitor to charge
// Take starting time
StartTicks = System.DateTime.Now.Ticks;
// Make the I/O line an input (with internal pull-up disabled)
RightIR.Active = false; // Set to input pin
// Measure the time for the capacitor node to discharge by waiting for the I/O line to go low
while (RightIR.Read() == true)
{
}
//StopTicks = new tick count;
StopTicks = System.DateTime.Now.Ticks;
// If time is less than the threshold value, then interpret result as a detection of a white line
TickDiff = StopTicks - StartTicks;
// Turn off IR LEDs (optional)
LEDIREmmitter.Write(false);
return(TickDiff);
}
/// <summary>
/// Constructor. Needs to interrupt pins to be provided and linked together in Hardware.
/// Blocking call for 1s to give sensor time to initialize.
/// </summary>
public DHT22(Cpu.Pin In, Cpu.Pin Out)
{
_dht22out = new TristatePort(Out, false, false, Port.ResistorMode.PullUp);
_dht22in = new SignalCapture(In, Port.ResistorMode.PullUp, Port.InterruptMode.InterruptEdgeBoth);
if (_dht22out.Active == false)
{
_dht22out.Active = true; // Make tristateport "output"
}
_dht22out.Write(true); // "high up" (standby state)
Thread.Sleep(1000); // 1s to pass the "unstable status" as per the documentation
}
public static void Main()
{
//Tristate Port init
//Tristate Port set as input mode
TristatePort tristate = new TristatePort((Cpu.Pin)(STM32.GPIO.GPIOD_15), false, false, Port.ResistorMode.PullUp);
Debug.Print("Port is input port.");
Thread.Sleep(1000);
//Tristate Port set as output mode
tristate.Active = true;
Debug.Print("Port is output port");
//Tristate set as high when output mode
tristate.Write(true);
Debug.Print("Output is high!");
Thread.Sleep(5000);
//Tristate set as low when output mode
tristate.Write(false);
Debug.Print("Output is low");
Thread.Sleep(1000);
}
// Execute transmission start sequence for commands
private static void StartTransmission()
{
if (!_dataPort.Active)
{
_dataPort.Active = true;
}
// transmission start sequence
_dataPort.Write(true);
_clkPort.Write(true);
_dataPort.Write(false);
_clkPort.Write(false);
_clkPort.Write(true);
_dataPort.Write(true);
_clkPort.Write(false);
}
public static void Main()
{
TristatePort tristatePort = new TristatePort(Cpu.Pin.GPIO_Pin4,
false, //initial state
false, //no glitch filter
Port.ResistorMode.PullUp);
Debug.Print("Port is inactive and acts as input port.");
Debug.Print("Input = " + tristatePort.Read());
tristatePort.Active = true;
Debug.Print("Port is active and acts as output port.");
tristatePort.Write(true);
}
public int read()
{
const int buffersize = 5;
int[] buffer = new int[buffersize];
int cnt = 7;
int idx = 0;
//clear buffer
for (int i = 0; i < buffersize; i++)
{
buffer[i] = 0;
}
//Write frame delimiter to sensor
Triport.Active = true;
Triport.Write(false);
Thread.Sleep(18); //sleep 18 miliseconds
Triport.Write(true);
//Now switch port to input mode and wait for signal
long time = Microseconds();
//(40) ~= 61 microseconds
//DelayMicroseconds(1);
long delta = Microseconds() - time;
delta = Microseconds() - time;
Debug.Print((delta / 10).ToString());
Triport.Active = false; //set tristate to disabled
//InputPort Inport = new InputPort(IOPin,true,
// Countdown values are pulled from arduiono code, may require tuning
int loopcount = 10000;
while (Triport.Read() == false)
{
if (loopcount-- == 0)
{
return(-2);
}
}
loopcount = 10000;
while (Triport.Read() == true)
{
if (loopcount-- == 0)
{
return(-3);
}
}
//read 40 bits or timeout
for (int i = 0; i < 40; i++)
{
loopcount = 10000;
while (Triport.Read() == false)
{
if (loopcount-- == 0)
{
return(-4);
}
}
long t = Microseconds();
loopcount = 10000;
while (Triport.Read() == true)
{
if (loopcount-- == 0)
{
return(-5);
}
}
if ((Microseconds() - t) > 40)
{
buffer[idx] |= (1 << cnt);
}
if (cnt == 0) //next byte?
{
cnt = 7;
idx++;
}
else
{
cnt--;
}
}
//write to vars
humidity = buffer[0];
temperature = buffer[2];
int sum = buffer[0] + buffer[2];
if (buffer[4] != sum)
{
return(-1);
}
return(0);
}
private bool Read(bool raiseEvent = true)
{
// The 'bitMask' also serves as edge counter: data bit edges plus extra ones at the beginning of the communication (presence pulse).
_bitMask = 1L << 42;
_sensorData = 0;
bool dataValid = false;
// Initiate communication
if (_portOut.Active == false)
{
_portOut.Active = true;
}
_portOut.Write(false); // Pull pin low
Thread.Sleep(5); // At lest 1 mSec.
_portIn.EnableInterrupt(); // Turn on the receiver
if (_portOut.Active)
{
_portOut.Active = false;
}
// Now the interrupt handler is getting called on each falling edge.
// The communication takes up to 5 ms, but the interrupt handler managed
// code takes longer to execute than is the duration of sensor pulse
// (interrupts are queued), so we must wait for the last one to finish
// and signal completion. 20 ms should be enough, 50 ms is safe.
// Set to 50 to minimize checksum and timeout errors. The higher the value
// the less timeout errors, consequently longer conversion time.
if (_dataReceived.WaitOne(200, true))
{
DataBytes[0] = (byte)((_sensorData >> 32) & 0xFF);
DataBytes[1] = (byte)((_sensorData >> 24) & 0xFF);
DataBytes[2] = (byte)((_sensorData >> 16) & 0xFF);
DataBytes[3] = (byte)((_sensorData >> 8) & 0xFF);
var checksum = (byte)(DataBytes[0] + DataBytes[1] + DataBytes[2] + DataBytes[3]);
if (checksum == (byte)(_sensorData & 0xFF))
{
dataValid = true;
Convert(DataBytes, raiseEvent);
}
else
{
if (SensorError != null)
{
SensorError(this, "RHT sensor data has invalid checksum.");
}
_temperature = float.MinValue;
_humidity = float.MinValue;
}
}
else
{
//_temperature = float.MinValue;
//_humidity = float.MinValue;
_portIn.DisableInterrupt(); // Stop receiver
if (SensorError != null)
{
SensorError(this, "RHT sensor data timeout.");
}
return(false);
}
return(dataValid);
}
public override void Write(bool state)
{
Mode = Socket.SocketInterfaces.IOMode.Output;
_port.Write(state);
}
/// <summary>
/// Access the sensor. Returns true if successful, false if it fails.
/// If false, please check the LastError value for more info.
/// </summary>
public bool ReadSensor()
{
uint[] buffer = new uint[80];
int nb, i;
/* REQUEST SENSOR MEASURE */
// Test if the 2 pins are connected together
bool rt = _dht22in.InternalPort.Read(); // Should be true
_dht22out.Write(false); // "low down": initiate transmission
bool rf = _dht22in.InternalPort.Read(); // Should be false
if (!rt || rf)
{
LastError = "The 2 pins are not hardwired together !";
_dht22out.Write(true); // "high up" (standby state)
return(false);
}
Thread.Sleep(1); // For "at least 1ms" as per the documentation
_dht22out.Write(true); // "high up" then listen
/* READ MEASURE */
_dht22out.Active = false; // Tristate Read
_dht22in.ReadTimeout = 500; // Timeout value in ms
nb = _dht22in.Read(false, buffer, 0, 80); // get the sensor answer
_dht22out.Active = true; // Tristate Write
_dht22out.Write(true); // "high up"
if (nb < 69)
{
LastError = "Did not receive enough data from the sensor";
return(false);
}
/* CONVERT MEASURE */
nb -= 2; // skip last 50us down
byte checksum = 0;
uint T = 0, H = 0;
// Convert CheckSum
for (i = 0; i < 8; i++, nb -= 2)
{
checksum |= (byte)(buffer[nb] > 35 ? 1 << i : 0);
}
// Convert Temperature
for (i = 0; i < 16; i++, nb -= 2)
{
T |= (uint)(buffer[nb] > 35 ? 1 << i : 0);
}
Temperature = ((float)(T & 0x7FFF)) * ((T & 0x8000) > 0 ? -1 : 1) / 10;
// Convert Humidity
for (i = 0; i < 10; i++, nb -= 2)
{
H |= (uint)(buffer[nb] > 35 ? 1 << i : 0);
}
Humidity = ((float)H) / 10;
// Check CheckSum
if ((((H & 0xFF) + (H >> 8) + (T & 0xFF) + (T >> 8)) & 0xFF) != checksum)
{
LastError = "Checksum Error";
return(false);
}
// No error case
LastError = "";
return(true);
}
