Support HYT271 sensor

src/libDevCom/CMakeLists.txt

@@ -31,6 +31,7 @@ target_sources(DevCom
   HIH4000.cpp
   HTS221.cpp
   SHT85.cpp
+  HYT271.cpp
   Si7021.cpp  
   NTCSensor.cpp
   PtSensor.cpp

src/libDevCom/HYT271.cpp

+#include "HYT271.h"
+#include "DeviceComRegistry.h"
+REGISTER_DEVCOM(HYT271, ClimateSensor)
+
+#include <unistd.h>
+#include <math.h>
+
+#include "NotSupportedException.h"
+#include "ChecksumException.h"
+
+HYT271::HYT271(std::shared_ptr<I2CCom> i2c)
+  : m_i2c(i2c)
+{ }
+
+HYT271::~HYT271()
+{ }
+
+void HYT271::init()
+{ }
+
+void HYT271::reset()
+{ }
+
+void HYT271::read()
+{
+  m_i2c->write_reg8(0x00);  // Send any value to start measurement
+  usleep(120e3);            // Conversion time is between 60ms to 100ms
+
+  std::vector<uint8_t> data(4);
+  m_i2c->read_block(data);
+
+  if ((data[0] & 0x40) != 0) {
+    // Got no new data - try re-reading after waiting a bit longer
+    usleep(200e3);
+    m_i2c->read_block(data);
+  }
+  if ((data[0] & 0x40) != 0) {
+    // Something is wrong
+    throw ComIOException("failed to read new data from HYT271 sensor");
+  }
+  m_humidity = ((data[0] & 0x3f) << 8 | data[1]) * (100.0 / (pow(2,14)-1.));
+  m_temperature = ((data[2] << 8 | (data[3] & 0xfc)) >> 2) * (165.0 / (pow(2,14)-1.)) - 40.;
+}
+
+uint HYT271::status() const
+{ return m_status; }
+
+float HYT271::temperature() const
+{ return m_temperature; }
+
+float HYT271::humidity() const
+{ return m_humidity; }
+
+float HYT271::pressure() const
+{ throw NotSupportedException("HYT271 does not have a pressure sensor"); return 0; }

src/libDevCom/HYT271.h

+#ifndef HYT271_H
+#define HYT271_H
+
+#include "ClimateSensor.h"
+#include "I2CCom.h"
+#include "ComIOException.h"
+
+#include <memory>
+
+/**
+ * The HYT271 climate sensor.
+ * [Datasheet](https://www.ist-ag.com/sites/default/files/DHHYT271_E.pdf)
+ */
+class HYT271 : public ClimateSensor
+{
+public:
+  HYT271(std::shared_ptr<I2CCom> i2c);
+  virtual ~HYT271();
+
+  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;
+
+private:
+  std::shared_ptr<I2CCom> m_i2c;
+
+  int m_status;
+  float m_temperature;
+  float m_humidity;
+};
+
+#endif // HYT271_H

src/libDevCom/python.cpp

@@ -8,6 +8,7 @@
 #include "HTS221.h"
 #include "Si7021.h"
 #include "SHT85.h"
+#include "HYT271.h"
 #include "HIH4000.h"
 #include "HIH6130.h"
 
@@ -1164,6 +1165,10 @@ void register_devcom(py::module& m) {
     .def(py::init<std::shared_ptr<I2CCom>>())
     .def("status", &SHT85::status);
   
+  py::class_<HYT271, PySensor_w_status<HYT271>, ClimateSensor, std::shared_ptr<HYT271>>(m, "HYT271")
+    .def(py::init<std::shared_ptr<I2CCom>>())
+    .def("status", &HYT271::status);
+  
   py::class_<HIH4000, PySensor<HIH4000>, ClimateSensor, std::shared_ptr<HIH4000>>(m, "HIH4000")
     .def(py::init<uint8_t, std::shared_ptr<ADCDevice>, std::shared_ptr<ClimateSensor>>())
     .def(py::init<uint8_t, std::shared_ptr<ADCDevice>, std::shared_ptr<ClimateSensor>, float>())