private UltrasonicReadEventArgs RetrieveSensorData()
{
try
{
// Send trigger pulse
_triggerPin.Write(GpioPinValue.Low);
Pi.Timing.SleepMicroseconds(2);
_triggerPin.Write(GpioPinValue.High);
Pi.Timing.SleepMicroseconds(12);
_triggerPin.Write(GpioPinValue.Low);
if (!_echoPin.WaitForValue(GpioPinValue.High, 50))
{
throw new TimeoutException();
}
_measurementTimer.Start();
if (!_echoPin.WaitForValue(GpioPinValue.Low, 50))
{
throw new TimeoutException();
}
_measurementTimer.Stop();
var elapsedTime = _measurementTimer.ElapsedMicroseconds;
_measurementTimer.Reset();
var distance = elapsedTime / 58.0;
if (elapsedTime > NoObstaclePulseMicroseconds)
{
distance = NoObstacleDistance;
}
return(new UltrasonicReadEventArgs(distance));
}
catch
{
return(UltrasonicReadEventArgs.CreateInvalidReading());
}
}
/// <summary>
/// Retrieves the sensor data.
/// </summary>
/// <returns>The event arguments that will be read from the sensor.</returns>
public DHT11Data RetrieveSensorData()
{
// Prepare buffer to store measure and checksum
var data = new byte[5];
// Start to communicate with sensor
// Inform sensor that must finish last execution and put it's state in idle
_dataPin.PinMode = GpioPinDriveMode.Output;
// Send request to transmission from board to sensor
_dataPin.Write(GpioPinValue.Low);
Pi.Timing.SleepMicroseconds(PullDownMicroseconds);
_dataPin.Write(GpioPinValue.High);
// Wait for sensor response
_dataPin.PinMode = GpioPinDriveMode.Input;
try
{
// Read acknowledgement from sensor
_dataPin.WaitForValue(GpioPinValue.Low, 50);
_dataPin.WaitForValue(GpioPinValue.High, 50);
// Begins data transmission
_dataPin.WaitForValue(GpioPinValue.Low, 50);
// Read 40 bits to acquire:
// 16 bit -> Humidity
// 16 bit -> Temperature
// 8 bit -> Checksum
var stopwatch = new HighResolutionTimer();
for (var i = 0; i < 40; i++)
{
stopwatch.Reset();
_dataPin.WaitForValue(GpioPinValue.High, 50);
stopwatch.Start();
_dataPin.WaitForValue(GpioPinValue.Low, 50);
stopwatch.Stop();
data[i / 8] <<= 1;
// Check if signal is 1 or 0
if (stopwatch.ElapsedMicroseconds > BitPulseMidMicroseconds)
{
data[i / 8] |= 1;
}
}
// End transmission
_dataPin.WaitForValue(GpioPinValue.High, 50);
var _validData = IsDataValid(data)
? new DHT11Data(_humid: ((data[0] + (data[1] * 0.1)) / 100.0), _temp: (data[2] + ((data[3] & 0x0f) * 0.1)))
: new DHT11Data();
if (_validData.IsInitialized)
{
_lastResult = _validData;
}
// Compute the checksum
return(_lastResult);
}
catch
{
return(new DHT11Data()
{
Humidity = 0.0, Temperature = 0.0
});
}
}
/// <summary>
/// Retrieves the sensor data.
/// </summary>
/// <returns>The event arguments that will be read from the sensor.</returns>
private DhtReadEventArgs RetrieveSensorData()
{
// Prepare buffer to store measure and checksum
var data = new byte[5];
// Start to comunicate with sensor
// Inform sensor that must finish last execution and put it's state in idle
_dataPin.PinMode = GpioPinDriveMode.Output;
// Send request to trasmission from board to sensor
_dataPin.Write(GpioPinValue.Low);
Pi.Timing.SleepMicroseconds(PullDownMicroseconds);
_dataPin.Write(GpioPinValue.High);
// Wait for sensor response
_dataPin.PinMode = GpioPinDriveMode.Input;
try
{
// Read acknowledgement from sensor
if (!_dataPin.WaitForValue(GpioPinValue.Low, 50))
{
throw new TimeoutException();
}
if (!_dataPin.WaitForValue(GpioPinValue.High, 50))
{
throw new TimeoutException();
}
// Begins data transmission
if (!_dataPin.WaitForValue(GpioPinValue.Low, 50))
{
throw new TimeoutException();
}
// Read 40 bits to acquire:
// 16 bit -> Humidity
// 16 bit -> Temperature
// 8 bit -> Checksum
var stopwatch = new HighResolutionTimer();
for (var i = 0; i < 40; i++)
{
stopwatch.Reset();
if (!_dataPin.WaitForValue(GpioPinValue.High, 50))
{
throw new TimeoutException();
}
stopwatch.Start();
if (!_dataPin.WaitForValue(GpioPinValue.Low, 50))
{
throw new TimeoutException();
}
stopwatch.Stop();
data[i / 8] <<= 1;
// Check if signal is 1 or 0
if (stopwatch.ElapsedMicroseconds > BitPulseMidMicroseconds)
{
data[i / 8] |= 1;
}
}
// End transmission
if (!_dataPin.WaitForValue(GpioPinValue.High, 50))
{
throw new TimeoutException();
}
// Compute the checksum
return(IsDataValid(data) ?
new DhtReadEventArgs(
humidityPercentage: DecodeHumidity(data),
temperatureCelsius: DecodeTemperature(data)) :
DhtReadEventArgs.CreateInvalidReading());
}
catch
{
return(DhtReadEventArgs.CreateInvalidReading());
}
}
/// <summary>
/// 返回传感器数据.
/// </summary>
/// <returns>从传感器读取的事件参数.</returns>
private DhtReadEventArgs RetrieveSensorData()
{
// 准备缓冲区以存储度量和校验和
var data = new byte[5];
// 开始与传感器通信
// 通知传感器必须完成最后一次执行并将其状态置于空闲状态
_dataPin.PinMode = GpioPinDriveMode.Output;
// 发送请求以将传输从板传输到传感器
_dataPin.Write(GpioPinValue.Low);
Pi.Timing.SleepMicroseconds(PullDownMicroseconds);
_dataPin.Write(GpioPinValue.High);
// 等待传感器响应
_dataPin.PinMode = GpioPinDriveMode.Input;
try
{
// 读取传感器的确认
if (!_dataPin.WaitForValue(GpioPinValue.Low, 50))
{
throw new TimeoutException();
}
if (!_dataPin.WaitForValue(GpioPinValue.High, 50))
{
throw new TimeoutException();
}
// 开始数据传输
if (!_dataPin.WaitForValue(GpioPinValue.Low, 50))
{
throw new TimeoutException();
}
// 读取40位以获取:
// 16 bit -> Humidity (湿度)
// 16 bit -> Temperature (温度)
// 8 bit -> Checksum (校验和)
var stopwatch = new HighResolutionTimer();
for (var i = 0; i < 40; i++)
{
stopwatch.Reset();
if (!_dataPin.WaitForValue(GpioPinValue.High, 50))
{
throw new TimeoutException();
}
stopwatch.Start();
if (!_dataPin.WaitForValue(GpioPinValue.Low, 50))
{
throw new TimeoutException();
}
stopwatch.Stop();
data[i / 8] <<= 1;
// 检查信号是1还是0
if (stopwatch.ElapsedMicroseconds > BitPulseMidMicroseconds)
{
data[i / 8] |= 1;
}
}
// 结束传输数据
if (!_dataPin.WaitForValue(GpioPinValue.High, 50))
{
throw new TimeoutException();
}
// 完成校验
return(IsDataValid(data) ?
new DhtReadEventArgs(
humidityPercentage: DecodeHumidity(data),
temperatureCelsius: DecodeTemperature(data)) :
DhtReadEventArgs.CreateInvalidReading());
}
catch
{
return(DhtReadEventArgs.CreateInvalidReading());
}
}
