Scd40 driver libhal 2.0

code/science/implementations/scd40.cpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <libhal-util/i2c.hpp>
+#include <libhal-util/serial.hpp>
+#include "scd40.hpp"
+
+scd40::create(hal::i2c& p_i2c, hal::steady_clock& clock){
+    scd40 scd40 = scd40(p_i2c, clock);
+    HAL_CHECK(scd40.start())
+
+}
+
+scd40::start(){}
+
+scd40::get_CO2{}
+
+scd40::get_RH(){}
+
+scd40::get_temp(){}

science/demos/CMakeLists.txt

@@ -20,9 +20,11 @@ libhal_build_demos(
   DEMOS
   co2_demo
   pressure_sensor_demo
+  scd40_demo
   color_sensor_demo
-  
+
   SOURCES
+  ../platform-implementations/scd40.cpp
   ../platform-implementations/pressure_sensor_bme680.cpp
   ../platform-implementations/color_sensor_opt4048.cpp
 

science/demos/applications/scd40_demo.cpp

@@ -0,0 +1,51 @@
+#include <libhal-armcortex/dwt_counter.hpp>
+#include <libhal-armcortex/startup.hpp>
+#include <libhal-armcortex/system_control.hpp>
+#include <libhal-util/serial.hpp>
+#include <libhal-util/steady_clock.hpp>
+#include <libhal/units.hpp>
+
+#include "../../platform-implementations/scd40.hpp"
+#include "../hardware_map.hpp"
+
+using namespace hal::literals;
+using namespace std::chrono_literals;
+namespace sjsu::science {
+
+hal::status application(application_framework& p_framework)
+{
+  // configure drivers
+  auto& i2c2 = *p_framework.i2c;
+  auto& clock = *p_framework.steady_clock;
+  auto& terminal = *p_framework.terminal;
+
+  auto scd40_sensor = HAL_CHECK(scd40::create(i2c2, clock));
+
+  while(true){
+        //get settings test
+        // scd40_sensor.stop();
+        // auto get = HAL_CHECK(scd40_sensor.get_settings());
+        // auto temp = get.temp_offset;
+        // auto alt = get.altitude;
+        // hal::print<64>(terminal, "%-5.2f\t%-5.2f\n", temp, alt);
+
+        // periodic readings are only updated every 5000ms (temperature)
+        hal::delay(clock, 5000ms);
+        auto rd = HAL_CHECK(scd40_sensor.read());
+        auto co2_levels = rd.co2;
+        auto temp = rd.temp;
+        auto RH_levels = rd.rh;
+
+
+        // hal::print<64>(terminal, "%-5.2f\t%-5.2f\t%-5.2f\n", co2_levels, temp, RH_levels);
+        // hal::delay(clock, 500ms);
+
+        hal::print<64>(terminal, "CO2 Levels: %f\n", co2_levels);
+        hal::print<64>(terminal, "Temperature %f\n", temp);
+        hal::print<64>(terminal, "RH Levels: %f\n", RH_levels);
+
+    }
+
+  return hal::success();
+}
+}  // namespace sjsu::science

science/platform-implementations/scd40.cpp

@@ -0,0 +1,129 @@
+// #pragma once
+
+#include "scd40.hpp"
+
+using namespace std::chrono_literals;
+using scd40_nm = sjsu::science::scd40;
+
+
+scd40_nm::scd40(hal::i2c& p_i2c, hal::steady_clock& p_clock) : m_i2c(p_i2c), m_clock(p_clock) {}
+
+hal::result<scd40_nm> scd40_nm::create(hal::i2c& p_i2c, hal::steady_clock& clock){
+    scd40 scd40(p_i2c, clock);
+    HAL_CHECK(scd40.start());
+    return scd40;
+
+}
+
+hal::status scd40_nm::start(){
+    std::array<hal::byte, 2> start_address =  { start_periodic_measurement_first_half, start_periodic_measurement_second_half };
+    HAL_CHECK(hal::write(m_i2c, addresses::device_address, start_address, hal::never_timeout()));
+    return hal::success();
+}
+
+hal::result<scd40_nm::scd40_read_data> scd40_nm::read() {
+    std::array<hal::byte, 2> read_address = {read_measurement_first_half, read_measurement_second_half };
+    std::array<hal::byte, 9> buffer;
+
+    HAL_CHECK(hal::write(m_i2c,addresses::device_address, read_address));
+    hal::delay(m_clock, 1ms);
+    HAL_CHECK(hal::read(m_i2c, addresses::device_address, buffer, hal::never_timeout()));
+
+    scd40_nm::scd40_read_data rd;
+    rd.co2 = buffer[0] << 8 | buffer[1];
+    rd.temp = (-45 + 175.0*(buffer[3] << 8 | buffer[4])/ (1 << 16));
+    rd.rh = 100.0 * (buffer[6] << 8 | buffer[7]) / (1 << 16);
+
+    return rd;
+}
+
+hal::status scd40_nm::stop() {
+    std::array<hal::byte, 2> stop_address =  { stop_periodic_measurement_first_half, stop_periodic_measurement_second_half };
+    HAL_CHECK(hal::write(m_i2c, addresses::device_address, stop_address, hal::never_timeout()));
+    return hal::success();
+}
+
+hal::result<scd40_nm::scd40_settings> scd40_nm::get_settings() {
+    std::array<hal::byte, 2> read_address_temp = {get_temperature_offset_first_half, get_temperature_offset_second_half };
+    std::array<hal::byte, 2> read_address_alt = { get_sensor_altitude_first_half, get_sensor_altitude_second_half };
+    std::array<hal::byte, 6> buffer;
+
+    HAL_CHECK(hal::write(m_i2c,addresses::device_address, read_address_temp));
+    hal::delay(m_clock, 1ms);
+    HAL_CHECK(hal::read(m_i2c, addresses::device_address, buffer, hal::never_timeout()));
+
+    scd40_nm::scd40_settings get;
+
+    get.temp_offset = 175 *(buffer[0] << 8 | buffer[1])/(1 << 16);
+
+    HAL_CHECK(hal::write(m_i2c,addresses::device_address, read_address_alt));
+    hal::delay(m_clock, 1ms);
+    HAL_CHECK(hal::read(m_i2c, addresses::device_address, buffer, hal::never_timeout()));
+    get.altitude = buffer[0]<<8 | buffer[1];
+
+    return get;
+}
+
+hal::status scd40_nm::set_settings( struct settings setting) {
+    if(setting.set_temp != 0){
+        int temp = int(((setting.set_temp*(1<<16)) / 175)) ;
+        hal::byte temp_first_half = (temp) >> 8;
+        hal::byte temp_second_half = temp & 0xff;
+        std::array<hal::byte, 4> set_temp_address = {set_temperature_offset_first_half, set_temperature_offset_second_half, temp_first_half, temp_second_half};
+        HAL_CHECK(hal::write(m_i2c,addresses::device_address,set_temp_address));
+        hal::delay(m_clock, 1ms);
+    }
+    if(setting.set_pressure != -1){
+        int pressure = int(setting.set_pressure/100);
+        hal::byte pressure_first_half = (pressure) >> 8;
+        hal::byte pressure_second_half = pressure & 0xff;
+        std::array<hal::byte, 4> set_pressure_address = {set_ambient_pressure_first_half, set_ambient_pressure_second_half, pressure_first_half, pressure_second_half};
+        HAL_CHECK(hal::write(m_i2c,addresses::device_address,set_pressure_address));
+        hal::delay(m_clock, 1ms);
+    } else if(setting.set_alt != 0){
+        int alt = int(setting.set_alt);
+        hal::byte alt_first_half = (alt) >> 8;
+        hal::byte alt_second_half = alt & 0xff;
+        std::array<hal::byte, 4> set_alt_address = {set_sensor_altitude_first_half, set_sensor_altitude_second_half, alt_first_half, alt_second_half};
+         HAL_CHECK(hal::write(m_i2c,addresses::device_address,set_alt_address));
+        hal::delay(m_clock, 1ms);
+    }
+
+    return hal::success();
+}
+
+hal::byte scd40_nm::generate_crc(std::array<hal::byte, 2> data){
+    uint16_t current_byte;
+    uint8_t crc_bit;
+    uint8_t crc = 0xFF;
+    uint8_t CRC8_POLYNOMIAL = 0x31;
+
+    for (current_byte = 0; current_byte < 2 ; ++current_byte) {
+        crc ^= (data[current_byte]);
+        for (crc_bit = 8; crc_bit > 0; --crc_bit) {
+            if (crc & 0x80)
+                crc = (crc << 1) ^ CRC8_POLYNOMIAL;
+            else
+                crc = (crc << 1);
+        }
+    }
+    return crc;
+}
+
+bool scd40_nm::validate_crc(std::array<hal::byte, 3> data) {
+    uint16_t current_byte;
+    uint8_t crc_bit;
+    uint8_t crc = 0xFF;
+    uint8_t CRC8_POLYNOMIAL = 0x31;
+
+    for (current_byte = 0; current_byte < 3 ; ++current_byte) {
+        crc ^= (data[current_byte]);
+        for (crc_bit = 8; crc_bit > 0; --crc_bit) {
+            if (crc & 0x80)
+                crc = (crc << 1) ^ CRC8_POLYNOMIAL;
+            else
+                crc = (crc << 1);
+        }
+    }
+    return crc == 0;
+}

science/platform-implementations/scd40.hpp

@@ -0,0 +1,72 @@
+#pragma once
+#include <libhal-util/i2c.hpp>
+#include <libhal-util/serial.hpp>
+#include <libhal-util/steady_clock.hpp>
+#include <libhal/units.hpp>
+
+
+//TODO: maybe later add CRC and config for altitude, ambient pressure, temperature offset (or look at setting persistent values)
+
+namespace sjsu::science {
+class scd40
+{
+private:
+
+    scd40(hal::i2c& p_i2c, hal::steady_clock& p_clock);
+    hal::i2c& m_i2c;
+    hal::steady_clock& m_clock;
+    hal::byte generate_crc(std::array<hal::byte, 2> data);
+    bool validate_crc(std::array<hal::byte, 3> data);
+
+
+    //TODO: revise output type
+    enum addresses {// deal with hal::byte later 
+        device_address = 0x62,
+        start_periodic_measurement_first_half = 0x21,
+        start_periodic_measurement_second_half = 0xb1,
+        read_measurement_first_half = 0xec,
+        read_measurement_second_half = 0x05,
+        stop_periodic_measurement_first_half = 0x3f,
+        stop_periodic_measurement_second_half = 0x86,
+        set_temperature_offset_first_half = 0x24,
+        set_temperature_offset_second_half = 0x1d,
+        get_temperature_offset_first_half = 0x23,
+        get_temperature_offset_second_half = 0x18,
+        set_sensor_altitude_first_half = 0x24,
+        set_sensor_altitude_second_half = 0x27,
+        get_sensor_altitude_first_half = 0x23,
+        get_sensor_altitude_second_half = 0x22,
+        set_ambient_pressure_first_half = 0xe0,
+        set_ambient_pressure_second_half = 0x00
+    };
+
+public:
+    struct scd40_read_data
+    {
+        double co2;
+        double temp;
+        double rh;
+    };
+
+    struct settings
+    {
+        double set_temp = 4;
+        double set_alt = 0;
+        double set_pressure = -1;
+    };
+
+    struct scd40_settings
+    {
+        double temp_offset;
+        double altitude;
+    };
+
+    static hal::result<scd40> create(hal::i2c& p_i2c,hal::steady_clock& p_clock);
+    hal::status start();
+    hal::result<scd40_read_data> read();
+    hal::status stop();
+    hal::result<scd40_settings> get_settings();
+    hal::status set_settings( struct settings setting);
+};
+
+} // namespace science