Files
WeatherService/Devices/PressureDevice.cs
2015-01-16 18:44:29 -05:00

483 lines
15 KiB
C#

using OneWireAPI;
using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
using WeatherService.Values;
namespace WeatherService.Devices
{
[DataContract]
public class PressureDevice : DeviceBase
{
private readonly byte[] _resetSequence = { 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0 }; // Binary sequence to reset the device
private readonly byte[] _readWord1Sequence = { 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0 }; // Binary sequence to read word 1
private readonly byte[] _readWord2Sequence = { 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0 }; // Binary sequence to read word 2
private readonly byte[] _readWord3Sequence = { 1, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0 }; // Binary sequence to read word 3
private readonly byte[] _readWord4Sequence = { 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0 }; // Binary sequence to read word 4
private readonly byte[] _readPressureSequence = { 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0 }; // Binary sequence to read pressure
private readonly byte[] _readTemperatureSequence = { 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0 }; // Binary sequence to read temperature
private const byte ChannelAccessCommand = 0xF5;
private const byte ConfigRead = 0xEC;
private const byte ConfigWrite = 0x8C;
private const byte ConfigPulseRead = 0xC8;
private readonly DeviceFamily12 _writeDevice; // Device for writing to the pressure sensor
private readonly DeviceFamily12 _readDevice; // Device for reading from the pressure sensor
private readonly Value _temperatureValue; // Last temperature (degrees C)
private readonly Value _pressureValue; // Last pressure (mbar)
private bool _readCalibration; // Have we read the calibration constants?
private int _calibration1; // Calibration constant
private int _calibration2; // Calibration constant
private int _calibration3; // Calibration constant
private int _calibration4; // Calibration constant
private int _calibration5; // Calibration constant
private int _calibration6; // Calibration constant
public PressureDevice(Session session, Device firstDevice, Device secondDevice)
: base(session, firstDevice, DeviceType.Pressure)
{
// Get both devices
var device1 = (DeviceFamily12) firstDevice;
var device2 = (DeviceFamily12) secondDevice;
// Get the state of both devices
var state1 = device1.ReadDevice();
var state2 = device2.ReadDevice();
// If both devices have the same power state then this isn't a proper pressure device
if (device1.IsPowered(state1) == device2.IsPowered(state2))
{
// Throw an exception
throw new Exception("Invalid TAI8570");
}
// The powered device is the write device - sort this out and remember which is which
if (device1.IsPowered(state1))
{
_writeDevice = device1;
_readDevice = device2;
}
else
{
_writeDevice = device2;
_readDevice = device1;
}
_temperatureValue = new Value(WeatherValueType.Temperature, this);
_pressureValue = new Value(WeatherValueType.Pressure, this);
Values.Add(WeatherValueType.Temperature, _temperatureValue);
Values.Add(WeatherValueType.Pressure, _pressureValue);
}
private void PrepPioForWrite()
{
var state = _writeDevice.ReadDevice();
_writeDevice.SetLatchState(0, true, state);
_writeDevice.SetLatchState(1, false, state);
_writeDevice.WriteDevice(state);
state = _readDevice.ReadDevice();
_readDevice.SetLatchState(0, false, state);
_readDevice.SetLatchState(1, false, state);
_readDevice.WriteDevice(state);
}
private void PrepPioForRead()
{
var state = _readDevice.ReadDevice();
_readDevice.SetLatchState(0, false, state);
_readDevice.SetLatchState(1, false, state);
_readDevice.WriteDevice(state);
state = _writeDevice.ReadDevice();
_writeDevice.SetLatchState(0, false, state);
_writeDevice.SetLatchState(1, false, state);
_writeDevice.WriteDevice(state);
}
private bool OpenPio(int pio)
{
var writeState = _writeDevice.ReadDevice();
var readDevice = _readDevice.ReadDevice();
_writeDevice.SetLatchState(pio, false, writeState);
_readDevice.SetLatchState(pio, false, readDevice);
_writeDevice.WriteDevice(writeState);
_writeDevice.WriteDevice(readDevice);
writeState = _writeDevice.ReadDevice();
readDevice = _readDevice.ReadDevice();
var result = (_writeDevice.GetLevel(pio, writeState) && _readDevice.GetLevel(pio, readDevice));
return result;
}
private bool OpenPioA()
{
return OpenPio(0);
}
private bool OpenPioB()
{
return OpenPio(1);
}
private bool SetupForWrite()
{
var data = new byte[3]; // Data buffer to send over the network
short dataCount = 0; // How many bytes of data to send
PrepPioForWrite();
Adapter.Select(_writeDevice.Id);
data[dataCount++] = ChannelAccessCommand;
data[dataCount++] = ConfigWrite;
data[dataCount++] = 0xFF;
Adapter.SendBlock(data, dataCount);
Adapter.ReadByte();
return true;
}
private bool SetupForRead()
{
var data = new byte[3]; // Data buffer to send over the network
short dataCount = 0; // How many bytes of data to send
PrepPioForRead();
Adapter.Select(_readDevice.Id);
data[dataCount++] = ChannelAccessCommand;
data[dataCount++] = ConfigRead;
data[dataCount++] = 0xFF;
Adapter.SendBlock(data, dataCount);
Adapter.ReadByte();
return true;
}
private bool SetupForPulseRead()
{
var data = new byte[3]; // Data buffer to send over the network
short dataCount = 0; // How many bytes of data to send
PrepPioForWrite();
Adapter.Select(_readDevice.Id);
data[dataCount++] = ChannelAccessCommand;
data[dataCount++] = ConfigPulseRead;
data[dataCount++] = 0xFF;
Adapter.SendBlock(data, dataCount);
Adapter.ReadByte();
return true;
}
private bool WriteBitSequence(IEnumerable<byte> sequence)
{
if (!SetupForWrite())
return false;
foreach (var t in sequence)
{
SendBit(t != 0);
}
SendBit(false);
return true;
}
private byte[] ReadBitSequence(IEnumerable<byte> sequence)
{
var result = new byte[16];
if (!WriteBitSequence(sequence))
return result;
result = GetBits(16);
OpenPioB();
return result;
}
private static void SendBit(bool value)
{
if (value)
{
Adapter.SendBit(0);
Adapter.SendBit(1);
Adapter.SendBit(1);
Adapter.SendBit(1);
Adapter.SendBit(0);
Adapter.SendBit(0);
}
else
{
Adapter.SendBit(0);
Adapter.SendBit(0);
Adapter.SendBit(1);
Adapter.SendBit(0);
Adapter.SendBit(0);
Adapter.SendBit(0);
}
}
private static bool ReadBit()
{
Adapter.ReadBit(); // Read PIO A #1
Adapter.ReadBit(); // Read PIO B #1
Adapter.ReadBit(); // Read PIO A #2
Adapter.ReadBit(); // Read PIO B #2
Adapter.ReadBit(); // Read PIO A #3
Adapter.ReadBit(); // Read PIO B #3
Adapter.ReadBit(); // Read PIO A #4
var data = Adapter.ReadBit();
var result = (data == 1);
Adapter.SendBit(0); // Write PIO A #1
Adapter.SendBit(1); // Write PIO B #1
Adapter.SendBit(0); // Write PIO A #2
Adapter.SendBit(1); // Write PIO B #2
Adapter.SendBit(1); // Write PIO A #3
Adapter.SendBit(1); // Write PIO B #3
Adapter.SendBit(1); // Write PIO A #4
Adapter.SendBit(1); // Write PIO B #4
return result;
}
private bool Reset()
{
return WriteBitSequence(_resetSequence);
}
private bool CheckConversionStatus()
{
int index;
if (!SetupForPulseRead())
return false;
for (index = 0; index < 100; index++)
if (Adapter.SendBit(0) == 0)
break;
return (index < 100);
}
private bool ReadCalibrationConstants()
{
int i;
if (!Reset()) return false;
var word1 = ReadBitSequence(_readWord1Sequence);
var word2 = ReadBitSequence(_readWord2Sequence);
var word3 = ReadBitSequence(_readWord3Sequence);
var word4 = ReadBitSequence(_readWord4Sequence);
_calibration1 = _calibration2 = _calibration3 = _calibration4 = _calibration5 = _calibration6 = 0;
for (i = 0; i < 15; i++)
{
_calibration1 = (_calibration1 << 1);
if (word1[i] == 1)
_calibration1 = _calibration1 + 1;
}
if (word1[15] == 1)
_calibration5 = 1;
for (i = 0; i < 10; i++)
{
_calibration5 = (_calibration5 << 1);
if (word2[i] == 1)
_calibration5 = _calibration5 + 1;
}
for (i = 10; i < 16; i++)
{
_calibration6 = (_calibration6 << 1);
if (word2[i] == 1)
_calibration6 = _calibration6 + 1;
}
for (i = 0; i < 10; i++)
{
_calibration4 = (_calibration4 << 1);
if (word3[i] == 1)
_calibration4 = _calibration4 + 1;
}
for (i = 10; i < 16; i++)
{
_calibration2 = (_calibration2 << 1);
if (word3[i] == 1)
_calibration2 = _calibration2 + 1;
}
for (i = 10; i < 16; i++)
{
_calibration2 = (_calibration2 << 1);
if (word4[i] == 1)
_calibration2 = _calibration2 + 1;
}
for (i = 0; i < 10; i++)
{
_calibration3 = (_calibration3 << 1);
if (word4[i] == 1)
_calibration3 = _calibration3 + 1;
}
return true;
}
private byte[] GetBits(byte bitCount)
{
var result = new byte[bitCount];
if (!SetupForRead())
return result;
for (var index = 0; index < bitCount; index++)
{
if (ReadBit())
result[index] = 1;
else
result[index] = 0;
}
return result;
}
private int ReadValue(IEnumerable<byte> sequence)
{
var result = 0;
if (!Reset())
return 0;
if (!WriteBitSequence(sequence))
return 0;
if (!CheckConversionStatus())
return 0;
if (!OpenPioA())
return 0;
var data = GetBits(16);
if (!OpenPioB())
return 0;
for (var index = 0; index < 16; index++)
{
result = (result << 1);
if (data[index] == 1)
result = result + 1;
}
return result;
}
private bool ReadSensorData()
{
var pressure = ReadValue(_readPressureSequence);
var temperature = ReadValue(_readTemperatureSequence);
double calibrationTemperature = (8 * _calibration5) + 20224;
var temperatureDifference = temperature - calibrationTemperature;
_temperatureValue.SetValue(20 + ((temperatureDifference * (_calibration6 + 50)) / 10240));
var offset = _calibration2 * 4 + (((_calibration4 - 512) * temperatureDifference) / 4096);
var sensitivity = _calibration1 + ((_calibration3 * temperatureDifference) / 1024) + 24576;
var actualPressure = ((sensitivity * (pressure - 7168)) / 16384) - offset;
_pressureValue.SetValue((actualPressure / 32) + 250);
return true;
}
private void ReadDevice()
{
if (!_readCalibration)
{
if (!ReadCalibrationConstants())
throw new Exception("Error reading calibration constants");
_readCalibration = true;
}
if (!ReadSensorData())
throw new Exception("Error reading Pressure and Temperature values");
}
internal override void RefreshCache()
{
ReadDevice();
base.RefreshCache();
}
#region Elevation code (not used yet)
//private double m_dElevation = 0.0; // Height above sea level (meters)
//public void set_height_over_sea_level_meter(double height)
//{
// m_dElevation = height;
//}
//public void set_height_over_sea_level_feet(double height)
//{
// m_dElevation = height * 0.3048;
//}
//public double get_height_over_sea_level_meter()
//{
// return m_dElevation;
//}
//public double get_height_over_sea_level_feet()
//{
// return (3.281 * m_dElevation);
//}
//public double get_calc_height_over_sea_level_meter()
//{
// return (288.15 / 0.0065) * (1 - Math.Pow((double) (getPressure_Pa() / 101325), (double) (0.0065 * (287.052 / 9.81))));
//}
#endregion
}
}