I think you need to get rid of the cpu.pin duplicate name mapping; the “using Microsoft.SPOT.Hardware;” line should have done that but it seems you have something else coming through overriding that. When I hover over cpu.pin in the default new project, I get the tooltip of “class Microsoft.SPOT.Hardware”, what do you get?
I have just done the following and it all works fine. Started a new project, without adding extra references. Copied the class definition from the driver you linked to below the [quote]public class Program[/quote] section. Added the statement in main() [quote] DHT11 MyDHT11 = new DHT11((Cpu.Pin)FEZ_Pin.Digital.Di6, (Cpu.Pin)FEZ_Pin.Digital.Di7); [/quote]
TheDHT11 declaration resolved correctly, all fine.
Try doing exactly what I did and see if you get a different result - just paste the driver content into the program.cs file created when you start a new project
And I get even more errors. I also tried putting the driver code in the program .cs.
Can some email the project so I can compare. My email is sidy.ndiongue@ hotmail.com
Thanks
using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using GHIElectronics.NETMF.FEZ;
namespace dht11_test
{
public class Program
{
/// <summary>
/// Class to read the single wire Humitidy/Temperature DHT11 sensor
/// It uses 2 interrupt pins connected together to access the sensor quick enough
/// </summary>
public class DHT11 : IDisposable
{
/// <summary>
/// Temperature in celcius degres
/// </summary>
public float Temperature { get; private set; }
/// <summary>
/// Humidity in percents
/// </summary>
public float Humidity { get; private set; }
/// <summary>
/// If not empty, gives the last error that occured
/// </summary>
public string LastError { get; private set; }
private TristatePort _dht11out;
private PinCapture _dht11in;
/// <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 DHT11(Cpu.Pin In, Cpu.Pin Out)
{
_dht11out = new TristatePort(Out, false, false, Port.ResistorMode.PullUp);
_dht11in = new PinCapture(In, Port.ResistorMode.PullUp, Port.InterruptMode.InterruptEdgeBoth);
if (_dht11out.Active == false) _dht11out.Active = true; // Make tristateport "output"
_dht11out.Write(true); //"high up" (standby state)
Thread.Sleep(1000); // 1s to pass the "unstable status" as per the documentation
}
#region IDisposable Members
public void Dispose()
{
_dht11out.Dispose();
_dht11in.Dispose();
}
#endregion
/// <summary>
/// Access the sensor. Returns true if successful, false if it fails.
/// If false, please check the LastError value for reason.
/// </summary>
public bool ReadSensor()
{
uint[] buffer = new uint[90];
int nb, i;
// Testing if the 2 pins are connected together
bool rt = _dht11in.InternalPort.Read(); // Should be true
_dht11out.Write(false); // "low down" : initiate transmission
bool rf = _dht11in.InternalPort.Read(); // Should be false
if (!rt || rf)
{
LastError = "The 2 pins are not hardwired together !";
_dht11out.Write(true); //"high up" (standby state)
return false;
}
Thread.Sleep(20); // For "at least 18ms" as per the documentation
_dht11out.Write(true); //"high up" then listen
nb = _dht11in.Read(false, buffer, 0, 90, 10); // get the sensor answer
if (nb < 81)
{
LastError = "Did not receive enough data from the sensor";
return false;
}
nb -= 2; // skip last 50us down
byte checksum = 0, decimalT = 0, integralT = 0, decimalRH = 0, integralRH = 0;
for (i = 0; i < 8; i++, nb -= 2) checksum |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) decimalT |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) integralT |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) decimalRH |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) integralRH |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
if (((integralRH + decimalRH + integralT + decimalT) & 0xFF) != checksum)
{
LastError = "Checksum Error";
return false;
}
Temperature = ((float)integralT) + ((float)decimalT) / 10;
Humidity = ((float)integralRH) + ((float)decimalRH) / 10;
LastError = "";
return true;
}
}
public static void Main()
{
DHT11 MyDHT11 = new DHT11((Cpu.Pin)FEZ_Pin.Digital.Di6, (Cpu.Pin)FEZ_Pin.Digital.Di7);
while (true)
{
if (MyDHT11.ReadSensor())
{
Debug.Print("Temperature = " + MyDHT11.Temperature.ToString() + "°C");
Debug.Print("Humidity = " + MyDHT11.Humidity.ToString() + "%");
}
else Debug.Print("DHT11 Error : " + MyDHT11.LastError);
Thread.Sleep(10000);
}
}
}
}
Try that way… the DHT11 class AFTER the Program class…
using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using GHIElectronics.NETMF.FEZ;
namespace dht11_test
{
public class Program
{
public static void Main()
{
DHT11 MyDHT11 = new DHT11((Cpu.Pin)FEZ_Pin.Digital.Di6, (Cpu.Pin)FEZ_Pin.Digital.Di7);
while (true)
{
if (MyDHT11.ReadSensor())
{
Debug.Print("Temperature = " + MyDHT11.Temperature.ToString() + "°C");
Debug.Print("Humidity = " + MyDHT11.Humidity.ToString() + "%");
}
else Debug.Print("DHT11 Error : " + MyDHT11.LastError);
Thread.Sleep(10000);
}
}
}
/// <summary>
/// Class to read the single wire Humitidy/Temperature DHT11 sensor
/// It uses 2 interrupt pins connected together to access the sensor quick enough
/// </summary>
public class DHT11 : IDisposable
{
/// <summary>
/// Temperature in celcius degres
/// </summary>
public float Temperature { get; private set; }
/// <summary>
/// Humidity in percents
/// </summary>
public float Humidity { get; private set; }
/// <summary>
/// If not empty, gives the last error that occured
/// </summary>
public string LastError { get; private set; }
private TristatePort _dht11out;
private PinCapture _dht11in;
/// <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 DHT11(Cpu.Pin In, Cpu.Pin Out)
{
_dht11out = new TristatePort(Out, false, false, Port.ResistorMode.PullUp);
_dht11in = new PinCapture(In, Port.ResistorMode.PullUp, Port.InterruptMode.InterruptEdgeBoth);
if (_dht11out.Active == false) _dht11out.Active = true; // Make tristateport "output"
_dht11out.Write(true); //"high up" (standby state)
Thread.Sleep(1000); // 1s to pass the "unstable status" as per the documentation
}
#region IDisposable Members
public void Dispose()
{
_dht11out.Dispose();
_dht11in.Dispose();
}
#endregion
/// <summary>
/// Access the sensor. Returns true if successful, false if it fails.
/// If false, please check the LastError value for reason.
/// </summary>
public bool ReadSensor()
{
uint[] buffer = new uint[90];
int nb, i;
// Testing if the 2 pins are connected together
bool rt = _dht11in.InternalPort.Read(); // Should be true
_dht11out.Write(false); // "low down" : initiate transmission
bool rf = _dht11in.InternalPort.Read(); // Should be false
if (!rt || rf)
{
LastError = "The 2 pins are not hardwired together !";
_dht11out.Write(true); //"high up" (standby state)
return false;
}
Thread.Sleep(20); // For "at least 18ms" as per the documentation
_dht11out.Write(true); //"high up" then listen
nb = _dht11in.Read(false, buffer, 0, 90, 10); // get the sensor answer
if (nb < 81)
{
LastError = "Did not receive enough data from the sensor";
return false;
}
nb -= 2; // skip last 50us down
byte checksum = 0, decimalT = 0, integralT = 0, decimalRH = 0, integralRH = 0;
for (i = 0; i < 8; i++, nb -= 2) checksum |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) decimalT |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) integralT |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) decimalRH |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) integralRH |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
if (((integralRH + decimalRH + integralT + decimalT) & 0xFF) != checksum)
{
LastError = "Checksum Error";
return false;
}
Temperature = ((float)integralT) + ((float)decimalT) / 10;
Humidity = ((float)integralRH) + ((float)decimalRH) / 10;
LastError = "";
return true;
}
}
}
namespace dht11_test
{
public class Program
{
main()
{
......
}
}
/// <summary>
/// Class to read the single wire Humitidy/Temperature DHT11 sensor
/// It uses 2 interrupt pins connected together to access the sensor quick enough
/// </summary>
public class DHT11 : IDisposable
{
.....etc
}
using System;
using System.Threading;
using GHIElectronics.NETMF.IO;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using GHIElectronics.NETMF.Hardware;
using GHIElectronics.NETMF.FEZ;
namespace dht11_test
{
public class Program
{
public static void Main()
{
DHT11 MyDHT11 = new DHT11((Cpu.Pin)FEZ_Pin.Digital.Di6, (Cpu.Pin)FEZ_Pin.Digital.Di7);
while (true)
{
if (MyDHT11.ReadSensor())
{
Debug.Print("Temperature = " + MyDHT11.Temperature.ToString() + "°C");
Debug.Print("Humidity = " + MyDHT11.Humidity.ToString() + "%");
}
else Debug.Print("DHT11 Error : " + MyDHT11.LastError);
Thread.Sleep(10000);
}
}
}
/// <summary>
/// Class to read the single wire Humitidy/Temperature DHT11 sensor
/// It uses 2 interrupt pins connected together to access the sensor quick enough
/// </summary>
public class DHT11 : IDisposable
{
/// <summary>
/// Temperature in celcius degres
/// </summary>
public float Temperature { get; private set; }
/// <summary>
/// Humidity in percents
/// </summary>
public float Humidity { get; private set; }
/// <summary>
/// If not empty, gives the last error that occured
/// </summary>
public string LastError { get; private set; }
private TristatePort _dht11out;
private PinCapture _dht11in;
/// <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 DHT11(Cpu.Pin In, Cpu.Pin Out)
{
_dht11out = new TristatePort(Out, false, false, Port.ResistorMode.PullUp);
_dht11in = new PinCapture(In, Port.ResistorMode.PullUp, Port.InterruptMode.InterruptEdgeBoth);
if (_dht11out.Active == false) _dht11out.Active = true; // Make tristateport "output"
_dht11out.Write(true); //"high up" (standby state)
Thread.Sleep(1000); // 1s to pass the "unstable status" as per the documentation
}
#region IDisposable Members
public void Dispose()
{
_dht11out.Dispose();
_dht11in.Dispose();
}
#endregion
/// <summary>
/// Access the sensor. Returns true if successful, false if it fails.
/// If false, please check the LastError value for reason.
/// </summary>
public bool ReadSensor()
{
uint[] buffer = new uint[90];
int nb, i;
// Testing if the 2 pins are connected together
bool rt = _dht11in.InternalPort.Read(); // Should be true
_dht11out.Write(false); // "low down" : initiate transmission
bool rf = _dht11in.InternalPort.Read(); // Should be false
if (!rt || rf)
{
LastError = "The 2 pins are not hardwired together !";
_dht11out.Write(true); //"high up" (standby state)
return false;
}
Thread.Sleep(20); // For "at least 18ms" as per the documentation
_dht11out.Write(true); //"high up" then listen
nb = _dht11in.Read(false, buffer, 0, 90, 10); // get the sensor answer
if (nb < 81)
{
LastError = "Did not receive enough data from the sensor";
return false;
}
nb -= 2; // skip last 50us down
byte checksum = 0, decimalT = 0, integralT = 0, decimalRH = 0, integralRH = 0;
for (i = 0; i < 8; i++, nb -= 2) checksum |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) decimalT |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) integralT |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) decimalRH |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
for (i = 0; i < 8; i++, nb -= 2) integralRH |= (byte)(buffer[nb] > 50 ? 1 << i : 0);
if (((integralRH + decimalRH + integralT + decimalT) & 0xFF) != checksum)
{
LastError = "Checksum Error";
return false;
}
Temperature = ((float)integralT) + ((float)decimalT) / 10;
Humidity = ((float)integralRH) + ((float)decimalRH) / 10;
LastError = "";
return true;
}
}
}
Now if you want to make it work as you tried to do first (dht11 class in a separate file, part of the project):
Insert the DHT11 class inside a namespace in your class file, example:
namespace mysensors
{
public class DHT11 : IDisposable
{
///...
}
}
Then, add the beginning of your main program file, add a line:
using mysensors;
I am interested to know about your tests with the DHT11. My own test worked fine at the begining, with reasonable accuracy, but with time (several months) the accuracy “drifter”. Now I am using DHT22 instead, which seem more stable in time and accept negative temperatures as well…
!