Added basic Battery class for handling battery related stuff

* Use ADC idf version to read voltage

* be prepared for handling differnt limits for Li-ION and LiFePo batteries

* Prepared for very basic SoC calculations
  * NOTE: SoC calculation on voltage measurement alone is always vers inprecise
  * SoC can be simply calculated based on a predefined Lookup table
  * this is still TODO

Author: LIFsCode

eloc610LowPowerPartition/src/Battery.cpp

@@ -0,0 +1,165 @@
+/*
+ * Created on Sun Apr 23 2023
+ *
+ * Project: International Elephant Project (Wildlife Conservation International)
+ *
+ * The MIT License (MIT)
+ * Copyright (c) 2023 Fabian Lindner
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+ * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#include <esp_log.h>
+#include <driver/adc.h>
+#include <esp_adc/adc_oneshot.h>
+#include "config.h"
+
+#include "CPPANALOG/analogio.h"
+
+#include "ElocSystem.hpp"
+#include "Battery.hpp"
+
+static const char* TAG = "Battery";
+
+//TODO: adjust these limits for Li-ION
+static const bat_limits_t C_LiION_LIMITS = {
+    .Voff = 2.7,
+    .Vlow = 3.18,
+    .Vfull = 3.3
+};
+
+static const bat_limits_t C_LiFePo_LIMITS = {
+    .Voff = 2.7,
+    .Vlow = 3.18,
+    .Vfull = 3.3
+};
+
+
+Battery::Battery() : 
+    mChargingEnabled(true),
+    mVoltageOffset(0.0), // TODO: read voltage offset from calibration info file (if present)
+    mSys(ElocSystem::GetInstance()),
+    mAdc(BAT_ADC),
+    mVoltage(0.0),
+    AVG_WINDOW(5) // TODO make this configureable
+{
+    //TODO: Read from config file if battery charging should be enabled by default
+    setChargingEnable(mChargingEnabled);
+
+    if (!mAdc.CheckCalFuse()) {
+        ESP_LOGW(TAG, "ADC %d has been uncalibrated!", BAT_ADC);
+    }
+}
+
+Battery::~Battery()
+{
+}
+
+
+bat_limits_t Battery::getLimits()
+{
+    if (mSys.hasIoExpander()) {
+       if (mSys.getIoExpander().hasLiIonBattery()) {
+            return C_LiION_LIMITS;
+       }
+       else {
+            return C_LiFePo_LIMITS;
+       }
+    }
+    return bat_limits_t();
+}
+
+float Battery::getVoltage() {
+    // disable charging first
+    if (esp_err_t err = setChargingEnable(false)) {
+        ESP_LOGI(TAG, "Failed to enable charging %s", esp_err_to_name(err));
+    }
+    mVoltage = 0.0;
+    float accum=0.0; 
+    float avg;
+    for (int i=0;  i<AVG_WINDOW;i++) {
+        if (mAdc.CheckCalFuse()) {
+            accum+= static_cast<float>(mAdc.GetVoltage())/1000.0; // CppAdc1::GetVoltage returns mV
+        }
+        else {
+            accum+= mAdc.GetRaw();
+        }
+    } 
+
+    mVoltage=accum/5.0;
+      
+
+    if (mChargingEnabled) {
+        if (esp_err_t err = setChargingEnable(mChargingEnabled)) 
+            ESP_LOGI(TAG, "Failed to enable charging %s", esp_err_to_name(err));
+    }
+    return mVoltage;
+}
+
+float Battery::getSoC()
+{
+    //TODO: Create a table for Voltage - SoC translation per battery type
+    getVoltage();
+    float soc = 0.0;
+    if (mSys.hasIoExpander() && mSys.getIoExpander().hasLiIonBattery()) {
+        if (mVoltage >= 4.2) {
+            soc = 100;
+        }
+    }
+    else {
+        if (mVoltage >= 3.4) {
+            soc = 100;
+        }
+    }
+    return 0.0f;
+}
+bool Battery::isLow()
+{
+    //TODO: trigger a voltage measurement if previous measurement is too old
+    if (mVoltage >= getLimits().Vfull) {
+        return true;
+    }
+    return false;
+}
+bool Battery::isFull()
+{
+    //TODO: trigger a voltage measurement if previous measurement is too old
+    if (mVoltage >= getLimits().Vfull) {
+        return true;
+    }
+    return false;
+}
+bool Battery::isEmpty()
+{
+    return false;
+}
+esp_err_t Battery::setChargingEnable(bool enable)
+{
+    if (mSys.hasIoExpander()) {
+       if (esp_err_t err = mSys.getIoExpander().chargeBattery(enable)) {
+            ESP_LOGI(TAG, "Failed to %s charging %s", enable ? "enable" : "disable", esp_err_to_name(err));
+            return err;
+       }
+    }
+    return ESP_OK;
+}
+
+esp_err_t Battery::setDefaultChargeEn(bool enable)
+{
+    mChargingEnabled = enable;
+    return setChargingEnable(enable);
+}
+

eloc610LowPowerPartition/src/Battery.hpp

@@ -0,0 +1,72 @@
+/*
+ * Created on Sun Apr 23 2023
+ *
+ * Project: International Elephant Project (Wildlife Conservation International)
+ *
+ * The MIT License (MIT)
+ * Copyright (c) 2023 Fabian Lindner
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+ * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef BATTERY_HPP_
+#define BATTERY_HPP_
+
+#include "CPPANALOG/analogio.h"
+#include "ElocSystem.hpp"
+#include "esp_err.h"
+
+typedef struct {
+    // use LiFePo defaults: just in case bat_limits_t is used uninitialized
+    float Voff = 2.7;
+    float Vlow = 3.18;
+    float Vfull = 3.3;
+}bat_limits_t;
+
+class Battery
+{
+private:
+    bool mChargingEnabled;
+    float mVoltageOffset;
+    ElocSystem& mSys;
+    CPPANALOG::CppAdc1 mAdc;
+    float mVoltage;
+
+    const uint32_t AVG_WINDOW;
+    
+    virtual esp_err_t setChargingEnable(bool enable); 
+    bat_limits_t getLimits();
+    Battery();
+    esp_err_t init();
+public:
+    virtual ~Battery();
+    static Battery& GetInstance() {
+        static Battery battery;
+        return battery;
+    }
+
+    virtual float getVoltage();
+    virtual float getSoC();
+
+    bool isLow();
+    bool isFull();
+    bool isEmpty();
+
+    virtual esp_err_t setDefaultChargeEn(bool enable); 
+    bool isBatteryPresent();
+};
+
+
+#endif // BATTERY_HPP_

eloc610LowPowerPartition/src/config.h

@@ -1,5 +1,6 @@
 #include <freertos/FreeRTOS.h>
 #include <driver/i2s.h>
+#include <driver/adc.h>
 #include "lis3dh_types.h"
 
 
@@ -40,6 +41,7 @@
         #define GPIO_BUTTON GPIO_NUM_0
         #define OTHER_GPIO_BUTTON GPIO_NUM_0
         #define VOLTAGE_PIN GPIO_NUM_34
+        #define BAT_ADC ADC1_CHANNEL_6
 
         /** Interrupt definitions
          *  lower levels are lower priorities

eloc610LowPowerPartition/src/main.cpp

@@ -33,6 +33,7 @@
 #include "version.h"
 
 #include "lis3dh.h"
+#include "Battery.hpp"
 #include "ElocSystem.hpp"
 #include "ManualWakeup.hpp"
 
@@ -674,9 +675,12 @@ I2SSampler *input;
 gpio_set_level(STATUS_LED, 0);
 gpio_set_level(BATTERY_LED, 0);
 
-ESP_LOGI(TAG, "Setting up System...");
+ESP_LOGI(TAG, "Setting up HW System...");
 ElocSystem::GetInstance();
 
+ESP_LOGI(TAG, "Setting up Battery...");
+Battery::GetInstance();
+
 
 //delay(30000);