BatteryMonitor.h

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#include "ReelTwo.h"
#include "core/AnimatedEvent.h"
 
#ifndef BatteryMonitor_h
#define BatteryMonitor_h
 
class BatteryMonitor: public AnimatedEvent
{
public:
    BatteryMonitor(
            uint8_t pin,
            uint16_t minVoltage = 3000,
            uint16_t maxVoltage = 4200,
            float scale = 2 * 3.3 * 1000,
            unsigned (*mapping)(unsigned, unsigned, unsigned) = sigmoidal) :
        fPin(pin),
        fMinVoltage(minVoltage),
        fMaxVoltage(maxVoltage),
        fScale(scale),
        fMapping(mapping)
    {
    }
 
    inline bool isBatteryPowered()
    {
        return isBatteryPowered(voltage());
    }
 
    inline bool isBatteryPowered(uint32_t voltage)
    {
        return voltage < fMaxVoltage;
    }
 
    inline void setRefreshCallback(uint32_t millis, void (*callback)())
    {
        fRefreshMillis = millis;
        fCallback = callback;
    }
 
    inline void setMapping(unsigned (*mapping)(unsigned, unsigned, unsigned))
    {
        fMapping = mapping;
    }
 
    inline unsigned level()
    {
        return level(voltage());
    }
 
    unsigned level(uint32_t voltage)
    {
        if (voltage <= fMinVoltage)
            return 0;
        if (voltage >= fMaxVoltage)
            return 100;
        return (*fMapping)(voltage, fMinVoltage, fMaxVoltage);
    }
 
    uint32_t voltage()
    {
    #ifdef ESP32
        uint32_t mV = (analogRead(fPin) * fScale) / 4096;
    #else
        uint32_t mV = (analogRead(fPin) * fScale) / 1024;
    #endif
        // Cache value
        fMilliVolts = mV;
        return mV;
    }
 
    virtual void animate() override
    {
        if (fCallback != nullptr && fNextRefresh < millis())
        {
            fCallback();
            fNextRefresh = millis() + fRefreshMillis;
        }
    }
 
    static unsigned sigmoidal(unsigned voltage, unsigned minVoltage, unsigned maxVoltage)
    {
        unsigned result = 105 - (105 / (1 + pow(1.724 * (voltage - minVoltage)/(maxVoltage - minVoltage), 5.5)));
        return result >= 100 ? 100 : result;
    }
 
    static inline unsigned asigmoidal(unsigned voltage, unsigned minVoltage, unsigned maxVoltage)
    {
        uint8_t result = 101 - (101 / pow(1 + pow(1.33 * (voltage - minVoltage)/(maxVoltage - minVoltage) ,4.5), 3));
        return result >= 100 ? 100 : result;
    }
 
    static inline unsigned linear(unsigned voltage, unsigned minVoltage, unsigned maxVoltage)
    {
        return (unsigned long)(voltage - minVoltage) * 100 / (maxVoltage - minVoltage);
    }
 
private:
    uint8_t fPin;
    unsigned fMinVoltage;
    unsigned fMaxVoltage;
    float fScale;
    unsigned (*fMapping)(unsigned, unsigned, unsigned);
    unsigned fMilliVolts = 0;
    uint32_t fRefreshMillis = 1000;
    uint32_t fNextRefresh = 0;
    void (*fCallback)() = nullptr;
};
 
#endif