humidity_sensor.hpp

Go to the documentation of this file.

 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  *  _____.___.                 .___                    .__.__      *
  *  \__  |   | ____   ____   __| _/___________    _____|__|  |     *
  *   /   |   |/ ___\ / ___\ / __ |\_  __ \__  \  /  ___/  |  |     *
  *   \____   / /_/  > /_/  > /_/ | |  | \// __ \_\___ \|  |  |__   *
  *   / ______\___  /\___  /\____ | |__|  (____  /____  >__|____/   *
  *   \/     /_____//_____/      \/            \/     \/            *
  *                         - Yggdrasil -                           *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * This software can be used by students and other personal of the *
  * Bern University of Applied Sciences under the terms of the MIT  *
  * license.                                                        *
  * For other persons this software is under the terms of the GNU   *
  * General Public License version 2.                               *
  *                                                                 *
  * Copyright © 2021, Bern University of Applied Sciences.     *
  * All rights reserved.                                            *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#pragma once
 
#include <cpp/common/attributes.hpp>
#include <cpp/common/types.hpp>
#include <cpp/common/utils.hpp>
 
namespace bsp::ygg::prph {
 
    class HumiditySensor {
    public:
        HumiditySensor() = delete;
 
        enum class Heat : u8 {
            _200mWFor1s     = 0x39,     
            _200mWFor0p1s   = 0x32,     
            _110mWFor1s     = 0x2F,     
            _110mWFor0p1s   = 0x24,     
            _20mWFor1s      = 0x1E,     
            _20mWFor0p1s    = 0x15,     
        };
 
        enum class Precision : u8 {
            High        = 0xFD,     
            Medium      = 0xF6,     
            Low         = 0xE0,     
        };
 
        static bool init() {
            bsp::I2CA::write(DeviceAddress, enumValue(Command::SoftReset));
            core::delay(2);
            return true;
        }
 
        static float getTemperature(Precision precision = Precision::High){
            return getSensorData(precision).sensorTemperature;
        }
 
        static float getHumidity(Precision precision = Precision::High){
            return getSensorData(precision).humidity;
        }
 
        static void enableHeater(Heat level) {
            bsp::I2CA::write(DeviceAddress, enumValue(level));
        }
 
    private:
 
        struct SensorData{
            float humidity;             
            float sensorTemperature;    
        };
 
        static SensorData getSensorData(Precision precision = Precision::High) {
            bsp::I2CA::write(DeviceAddress, enumValue(precision));
            core::delay(10);                                        // Delay until the measurement is done, there is no other option
 
            auto rawData = bsp::I2CA::read<SensorDataRaw>(DeviceAddress);
 
            SensorData data;
            data.sensorTemperature = -45 + 175 * float((u16(rawData.th) << 8) | rawData.tl) / 0xFFFF;
            data.humidity = -6 + 125 * float((u16(rawData.rhh) << 8) | rawData.rhl) / 0xFFFF;
 
            if (data.humidity > 100) data.humidity = 100;
            else if(data.humidity < 0) data.humidity = 0;
 
            return data;
 
        }
 
        struct SensorDataRaw {
            u8 th;          
            u8 tl;          
            u8 tcrc8;       
            u8 rhh;         
            u8 rhl;         
            u8 rhcrc8;      
        };
 
        enum class Command : u8 {
            ReadSerial = 0x89,      
            SoftReset  = 0x94,      
        };
 
        constexpr static inline u8 DeviceAddress = 0x88;        
 
    };
 
}