public float ReadPressure()
{
var status = I2cUtils.Read8(device, C_Status);
if ((status & 2) == 2)
{
Int32 rawData = (Int32)I2cUtils.Read24LE(device, C_PressOutXL + 0x80);
return(rawData * pressureFactor);
}
return(0.0f);
}
public float ReadTemperature()
{
var status = I2cUtils.Read8(device, C_Status);
if ((status & 1) == 1)
{
var rawData = (Int16)I2cUtils.Read16LE(device, C_TempOutL + 0x80);
return(convertTemperature(rawData));
}
// TODO: throw exception or return status code if reading is ready or not?
return(0.0f);
}
public float ReadHumidity()
{
var status = I2cUtils.Read8(device, C_Status);
if ((status & 2) == 2)
{
var rawData = (Int16)I2cUtils.Read16LE(device, C_HumidityOutL + 0x80);
return(convertHumidity(rawData));;
}
// TODO: throw exception or return status code if reading is ready or not?
return(0.0f);
}
private Func <Int16, float> GetHumidityConverter()
{
byte h0h2 = I2cUtils.Read8(device, C_H0H2 + 0x80);
byte h1h2 = I2cUtils.Read8(device, C_H1H2 + 0x80);
float h0 = h0h2 * 0.5f;
float h1 = h1h2 * 0.5f;
Int16 h0t0out = (Int16)I2cUtils.Read16LE(device, C_H0T0Out + 0x80);
Int16 h1t0out = (Int16)I2cUtils.Read16LE(device, C_H1T0Out + 0x80);
float m = (h1 - h0) / (h0t0out - h1t0out);
float b = h0 - (m * h0t0out);
return(t => t * m + b);
}
protected override async Task InitAsync()
{
device = await I2cUtils.GetDeviceAsync(C_Addr, I2cBusSpeed.FastMode);
// PD RESERVED BDU ODR1-0
// 1 0000 1 11
// active, n/a, non-continous, 12.5Hz for both
I2cUtils.WriteByte(device, C_Ctrl1, 0x87);
// RESERVED AVGT2-0 AVGH2-0
// 00 011 011
// n/a, average: 16, 32 (temperature, humidity)
I2cUtils.WriteByte(device, C_AvConf, 0x1B);
convertTemperature = GetTemperatureConverter();
convertHumidity = GetHumidityConverter();
}
private Func <Int16, float> GetTemperatureConverter()
{
byte rawMsb = I2cUtils.Read8(device, C_T1T0 + 0x80);
byte t0Lsb = I2cUtils.Read8(device, C_T0C8 + 0x80);
byte t1Lsb = I2cUtils.Read8(device, C_T1C8 + 0x80);
UInt16 t0c8 = (UInt16)(((UInt16)(rawMsb & 0x03) << 8) | (UInt16)t0Lsb);
UInt16 t1c8 = (UInt16)(((UInt16)(rawMsb & 0x0C) << 6) | (UInt16)t1Lsb);
float t0 = t0c8 / 8.0f;
float t1 = t1c8 / 8.0f;
Int16 t0out = (Int16)I2cUtils.Read16LE(device, C_T0Out + 0x80);
Int16 t1out = (Int16)I2cUtils.Read16LE(device, C_T1Out + 0x80);
float m = (t1 - t0) / (t1out - t0out);
float b = t0 - (m * t0out);
return(t => t * m + b);
}
protected override async Task InitAsync()
{
device = await I2cUtils.GetDeviceAsync(C_Addr, I2cBusSpeed.FastMode);
// PD ODR2-0 DIFF BDU RESET SIM
// 1 100 0 1 0 0
// Active mode, 25Hz, default, non-continous, disable, default
I2cUtils.WriteByte(device, C_Ctrl1, 0xC4);
// AVGP1-0 AVGT1-0
// 01 01
// N. internal average: 32, 16 (pressure, temperature)
I2cUtils.WriteByte(device, C_ResConf, 0x05);
// F_MODE2 F_MODE1 F_MODE0
// 1 1 0
// FIFO_MEAN_MODE: running average filtered pressure
I2cUtils.WriteByte(device, C_FifoCtrl, 0xC0);
// BOOT FIFO_EN WTM_EN FIFO_MEAN I2C_EN SWRESET AUTOZERO ONESHOT
// 0 1 0 0 0 0 0 0
// normal, enable, disable, disable, i2c enable, normal, normal, waiting
I2cUtils.WriteByte(device, C_Ctrl2, 0x40);
}
