Add support for HTS221 climate sensor

src/libDevCom/CMakeLists.txt

@@ -25,6 +25,7 @@ target_sources(DevCom
   #BME280.cpp
   HIH6130.cpp
   HIH4000.cpp
+  HTS221.cpp
   SHT85.cpp
   Si7021.cpp  
   NTCSensor.cpp

src/libDevCom/HTS221.cpp

+#include "HTS221.h"
+
+#include <unistd.h>
+#include <math.h>
+
+#include "NotSupportedException.h"
+#include "ChecksumException.h"
+
+HTS221::HTS221(std::shared_ptr<I2CCom> i2c)
+  : m_i2c(i2c)
+{ }
+
+void HTS221::init()
+{
+  // Read temperature calibration
+  m_T0_degC=m_i2c->read_reg8(0x32);
+  m_T1_degC=m_i2c->read_reg8(0x33);
+
+  uint8_t T1T0msb = m_i2c->read_reg8(0x35);
+  m_T0_degC|=((T1T0msb&0x3)<<8);
+  m_T1_degC|=((T1T0msb&0xC)<<6);  
+
+  m_T0_OUT=(m_i2c->read_reg8(0x3D)<<8)|(m_i2c->read_reg8(0x3C)<<0);
+  m_T1_OUT=(m_i2c->read_reg8(0x3F)<<8)|(m_i2c->read_reg8(0x3E)<<0);
+  
+  // Read humidity calibration
+  m_H0_rH=m_i2c->read_reg8(0x30);
+  m_H1_rH=m_i2c->read_reg8(0x31);
+
+  m_H0_T0_OUT=(m_i2c->read_reg8(0x37)<<8)|(m_i2c->read_reg8(0x36)<<0);
+  m_H1_T0_OUT=(m_i2c->read_reg8(0x3B)<<8)|(m_i2c->read_reg8(0x3A)<<0);
+
+  // Power on the device
+  powerDown(false);
+}
+
+void HTS221::reset()
+{ }
+
+void HTS221::powerDown(bool value)
+{
+  uint8_t CTRL_REG1=m_i2c->read_reg8(0x20);
+  m_i2c->write_reg8(0x20, CTRL_REG1|((!value)<<7));  
+}
+
+void HTS221::oneShot()
+{
+  uint8_t CTRL_REG2=m_i2c->read_reg8(0x21);
+  m_i2c->write_reg8(0x21, CTRL_REG2|1);
+}
+
+void HTS221::read()
+{
+  oneShot(); // Start a one shot measurement
+  do
+    { m_status = m_i2c->read_reg8(0x27); }
+  while(((m_status&0x3)!=3));
+
+  // Get temperature
+  int16_t T_OUT=(m_i2c->read_reg8(0x2B)<<8)|(m_i2c->read_reg8(0x2A)<<0);
+
+  m_temperature = (m_T1_degC - m_T0_degC)*(T_OUT - m_T0_OUT)/(m_T1_OUT - m_T0_OUT) + m_T0_degC;
+  m_temperature/=8;
+
+  // Get humidity
+  int16_t H_T_OUT=(m_i2c->read_reg8(0x29)<<8)|(m_i2c->read_reg8(0x28)<<0);
+
+  m_humidity = (m_H1_rH - m_H0_rH)*(H_T_OUT - m_H0_T0_OUT)/(m_H1_T0_OUT - m_H0_T0_OUT) + m_H0_rH;
+  m_humidity/=2;
+}
+
+uint HTS221::status() const
+{ return m_status; }
+
+float HTS221::temperature() const
+{ return m_temperature; }
+
+float HTS221::humidity() const
+{ return m_humidity; }
+
+float HTS221::pressure() const
+{ throw NotSupportedException("Si7021 does not have a pressure sensor"); }

src/libDevCom/HTS221.h

+#ifndef HTS221_H
+#define HTS221_H
+
+#include "ClimateSensor.h"
+#include "I2CCom.h"
+
+#include <memory>
+
+/**
+ * The HTS221 climate sensor.
+ * [Datasheet](https://www.st.com/resource/en/datasheet/hts221.pdf)
+ */
+class HTS221 : public ClimateSensor
+{
+public:
+  HTS221(std::shared_ptr<I2CCom> i2c);
+  virtual ~HTS221() =default;
+  
+  virtual void init();
+  virtual void reset();
+  virtual void read();
+
+  virtual unsigned status() const;
+  virtual float temperature() const;
+  virtual float humidity() const;
+  virtual float pressure() const;
+
+  //! Set power down bit
+  /**
+   * \param value True(/false) to enable(/disable) power down mode
+   */
+  void powerDown(bool value);
+
+  //! Trigger a new measurement when running in one-shot mode.
+  void oneShot();
+
+private:
+  std::shared_ptr<I2CCom> m_i2c;
+
+  //
+  // Calibration information
+
+  // Temperature
+  int16_t m_T0_degC;
+  int16_t m_T1_degC;
+  int16_t m_T0_OUT;
+  int16_t m_T1_OUT;
+
+  // Humidity
+  int16_t m_H0_rH;
+  int16_t m_H1_rH;
+  int16_t m_H0_T0_OUT;
+  int16_t m_H1_T0_OUT;
+
+  //
+  // Data
+  int m_status;
+  float m_temperature;
+  float m_humidity;
+};
+
+#endif // HTS221_H

src/libDevCom/python.cpp

@@ -3,6 +3,7 @@
 
 #include "ClimateSensor.h"
 #include "NTCSensor.h"
+#include "HTS221.h"
 #include "Si7021.h"
 #include "SHT85.h"
 #include "HIH6130.h"
@@ -647,13 +648,15 @@ void register_devcom(py::module& m) {
     .def("pressure", &ClimateSensor::pressure)
     .def("dewPoint", &ClimateSensor::dewPoint);
  
-  py::class_<NTCSensor, PySensor<NTCSensor>, ClimateSensor, std::shared_ptr<NTCSensor>>(m, "NTCSensor")
-    .def(py::init<uint8_t, std::shared_ptr<ADCDevice>, bool, float, float, float, bool, float>())
-    .def(py::init<uint8_t, std::shared_ptr<ADCDevice>, bool, float, float, float, bool, float, float>());
-  
+  py::class_<NTCSensor, PySensor<NTCSensor>, ClimateSensor, std::shared_ptr<NTCSensor>>(m, "NTCSensor");
+
+  py::class_<HTS221, PySensor_w_status<HTS221>, ClimateSensor, std::shared_ptr<HTS221>>(m, "HTS221")
+    .def(py::init<std::shared_ptr<I2CCom>>())
+    .def("status", &HTS221::status);
+
   py::class_<Si7021, PySensor<Si7021>, ClimateSensor, std::shared_ptr<Si7021>>(m, "Si7021")
     .def(py::init<std::shared_ptr<I2CCom>>());
-  
+
   py::class_<SHT85, PySensor_w_status<SHT85>, ClimateSensor, std::shared_ptr<SHT85>>(m, "SHT85")
     .def(py::init<std::shared_ptr<I2CCom>>())
     .def("status", &SHT85::status);