Implemented driver for BH1750 light sensor

dev/sensor/CMakeLists.txt

@@ -1 +1,2 @@
-add_subdirectory(htu21d)
+add_subdirectory(htu21d)
+add_subdirectory(bh1750)

dev/sensor/bh1750/CMakeLists.txt

@@ -0,0 +1,4 @@
+add_library(bh1750 INTERFACE)
+target_link_libraries(bh1750 INTERFACE types)
+target_link_libraries(bh1750 INTERFACE thread)
+target_include_directories(bh1750 INTERFACE export)

dev/sensor/bh1750/export/dev/sensor/bh1750.hpp

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+//!
+//! \file
+//! \brief BH1750 Digital 16bit Serial Output Type Ambient Light Sensor IC
+//!  See, https://e-radionica.com/productdata/BH1750FVI.pdf
+//!
+
+#ifndef __DEV_SENSOR_BH1750_HPP__
+#define __DEV_SENSOR_BH1750_HPP__
+
+#include <ecl/err.hpp>
+#include <ecl/thread/thread.hpp>
+
+namespace ecl
+{
+
+namespace sensor {
+
+//! \brief This namespace contains sensor specific parameters
+//!
+namespace bh1750_cfg {
+
+//! \brief Represents I2C slave address for BH1750 sensor.
+//!  According to RM, it is possible to select 2 type of I2C slave-address.
+//!  It depends on ADDR pin state: pulled-down to GND - low, pulled-up to VCC - high
+//!
+enum class i2c_address {
+    low,
+    high,
+};
+
+//! \brief Represents resolution mode BH1750 sensor.
+//!  According to RM, there are 3 resolution modes:
+//!  L-mode (4lx), H-mode (1lx) and H-mode2 (0.5lx)
+//!
+enum class resolution {
+    low,
+    high,
+    high2
+};
+
+}; // bh1750_cfg
+
+
+//! \brief BH1750 Ambient Light sensor driver implementation.
+//! \tparam i2c_dev I2C generic bus driver
+//! \tparam address I2C slave address.
+//!  This parameter can be value of type bh1750_cfg::i2c_address
+//!
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+class bh1750 {
+public:
+    bh1750() = delete;
+    ~bh1750() = delete;
+
+    //! \brief Inits sensor and underlying I2C platform bus.
+    //! \retval Status of operation.
+    //!
+    static ecl::err init();
+
+    //! \brief Sets sensor resolution mode. Default mode is bh1750_cfg::high.
+    //! \param[in] resolution Resolution mode.
+    //!  This parameter can be value of type bh1750_cfg::resolution.
+    //!
+    static void set_resolution(bh1750_cfg::resolution resolution);
+
+    //! \brief Returns current sensor resolution mode.
+    //! \retval Current resolution mode.
+    //!  The return value can be value of type bh1750_cfg::resolution.
+    //!
+    static bh1750_cfg::resolution get_resolution();
+
+    //! \brief Reads raw illuminance sample from sensor.
+    //! \details This method blocks until measurement is not finished.
+    //!  Measurement time depends on resolution mode: at least 25 ms for low mode
+    //!  and 200 ms for high and high2 modes.
+    //! \param[out] sample  Raw sample value will be written in this parameter.
+    //! \retval Status of the operation.
+    //!
+    static ecl::err get_illuminance_sample(uint16_t &sample);
+
+    //! \brief Reads sample from sensor and converts to a physical value.
+    //! \details This method blocks until measurement is not finished.
+    //!  Measurement time depends on resolution mode: at least 25 ms for low mode
+    //!  and 200 ms for high and high2 modes.
+    //! \param[out] value Illuminance in (1000 * (illuminance in lx))
+    //!  will be written in this parameter.
+    //! \retval Status of the operation.
+    //!
+    static ecl::err get_illuminance(uint32_t &value);
+
+private:
+    //! Returns I2C slave address based on class template parameter
+    static constexpr uint8_t pick_i2c_slave_address();
+
+    //! I2C slave address when ADDR pin is pulled down to GND
+    static constexpr uint8_t i2s_address_low = 0x46;
+    //! I2C slave address when ADDR pin is pulled up to VCC
+    static constexpr uint8_t i2s_address_high = 0xB8;
+
+    //! Maximum measurement time for low resolution mode according to RM
+    static constexpr uint16_t measurement_time_ms_low = 25;
+    //! Maximum measurement time for high and high2 resolution modes according to RM
+    static constexpr uint16_t measurement_time_ms_high = 200;
+
+    //! Current resolution mode
+    static bh1750_cfg::resolution resolution;
+
+    //! List of commands, supported by sensor
+    enum {
+        CMD_POWER_DOWN = 0x0,
+        CMD_POWER_UP = 0x1,
+        CMD_RESET = 0x7,
+        CMD_CONTINUOUSLY_HR_MODE = 0x10,
+        CMD_CONTINUOUSLY_HR_MODE2 = 0x11,
+        CMD_CONTINUOUSLY_LR_MODE = 0x13,
+        CMD_ONE_TIME_HR_MODE = 0x20,
+        CMD_ONE_TIME_HR_MODE2 = 0x21,
+        CMD_ONE_TIME_LR_MODE = 0x23,
+    };
+};
+
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+bh1750_cfg::resolution bh1750<i2c_dev, address>::resolution = bh1750_cfg::resolution::high;
+
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+ecl::err bh1750<i2c_dev, address>::init()
+{
+    return i2c_dev::init();
+}
+
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+constexpr uint8_t bh1750<i2c_dev, address>::pick_i2c_slave_address()
+{
+    if (address == bh1750_cfg::i2c_address::low) {
+        return i2s_address_low;
+    } else {
+        return i2s_address_high;
+    }
+}
+
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+void bh1750<i2c_dev, address>::set_resolution(bh1750_cfg::resolution resolution)
+{
+    bh1750<i2c_dev, address>::resolution = resolution;
+}
+
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+bh1750_cfg::resolution bh1750<i2c_dev, address>::get_resolution()
+{
+    return resolution;
+}
+
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+ecl::err bh1750<i2c_dev, address>::get_illuminance_sample(uint16_t &sample)
+{
+    uint8_t i2c_addr = pick_i2c_slave_address();
+
+    uint8_t cmd = CMD_ONE_TIME_HR_MODE;
+    uint16_t delay = measurement_time_ms_high;
+
+    switch (resolution) {
+    case bh1750_cfg::resolution::high:
+        cmd = CMD_ONE_TIME_HR_MODE;
+        delay = measurement_time_ms_high;
+        break;
+    case bh1750_cfg::resolution::high2:
+        cmd = CMD_ONE_TIME_HR_MODE2;
+        delay = measurement_time_ms_high;
+        break;
+    case bh1750_cfg::resolution::low:
+        cmd = CMD_ONE_TIME_LR_MODE;
+        delay = measurement_time_ms_low;
+        break;
+    default:
+        break;
+    }
+
+    i2c_dev::platform_handle().set_slave_addr(i2c_addr);
+
+    i2c_dev::lock();
+    err rc = i2c_dev::set_buffers(&cmd, nullptr, 1);
+    if (rc == err::ok) {
+        rc = i2c_dev::xfer();
+    }
+    i2c_dev::unlock();
+
+    if (rc != err::ok) {
+        return rc;
+    }
+
+    ecl::os::this_thread::sleep_for(delay);
+
+    uint8_t data[2] = {};
+
+    i2c_dev::lock();
+    rc = i2c_dev::set_buffers(nullptr, data, sizeof(data));
+    if (rc == err::ok) {
+        rc = i2c_dev::xfer();
+    }
+    i2c_dev::unlock();
+
+    if (rc != err::ok) {
+        return rc;
+    }
+
+    sample = ((data[0] << 8) | data[1]);
+
+    return err::ok;
+
+}
+
+template <class i2c_dev, bh1750_cfg::i2c_address address>
+ecl::err bh1750<i2c_dev, address>::get_illuminance(uint32_t &value)
+{
+    uint16_t sample = 0;
+
+    err rc = get_illuminance_sample(sample);
+    if (rc != err::ok) {
+        return rc;
+    }
+
+    value = ((1000000 * static_cast<uint64_t>(sample)) / 1200);
+
+    //! low resolution provides 4lx per count and high2 0.5lx per count
+    if (resolution == bh1750_cfg::resolution::low) {
+        value *= 4;
+    } else if (resolution == bh1750_cfg::resolution::high2) {
+        value /= 2;
+    }
+
+    return err::ok;
+}
+
+
+}; // namespace sensor
+
+}; // namespace ecl
+
+#endif //  __DEV_SENSOR_BH1750_HPP__