#pragma once // // FILE: ACS712.h // AUTHOR: Rob Tillaart, Pete Thompson // VERSION: 0.3.1 // DATE: 2020-08-02 // PURPOSE: ACS712 library - current measurement // // Tested with a RobotDyn ACS712 20A breakout + UNO. // #include "Arduino.h" #define ACS712_LIB_VERSION (F("0.3.1")) // ACS712_FF_SINUS == 1.0/sqrt(2) == 0.5 * sqrt(2) // should be smaller in practice 0.5 ? #define ACS712_FF_SINUS (1.0/sqrt(2)) #define ACS712_FF_SQUARE (1.0) #define ACS712_FF_TRIANGLE (1.0/sqrt(3)) #define ACS712_FF_SAWTOOTH (1.0/sqrt(3)) #define ACS712_DEFAULT_FREQ 50 #define ACS712_DEFAULT_NOISE 21 class ACS712 { public: // NOTE: // One can quite precisely tune the value of the sensor // (1) the milliVolt per Ampere and // (2) the volts parameter. // // TYPE mV per Ampere // 5A 185.0 // 20A 100.0 // 30A 66.0 ACS712(uint8_t analogPin, float volts = 5.0, uint16_t maxADC = 1023, float mVperAmpere = 100); // returns mA peak2peak current. float mA_peak2peak(float frequency = ACS712_DEFAULT_FREQ, uint16_t cycles = 1); // returns mA // blocks 20-21 ms to sample a whole 50 or 60 Hz period. // works with peak2peak level and (crest) Form Factor. // lower frequencies block longer. float mA_AC(float frequency = ACS712_DEFAULT_FREQ, uint16_t cycles = 1); // returns mA // blocks 20-21 ms to sample a whole 50 or 60 Hz period. // works with sampling. // lower frequencies block longer. float mA_AC_sampling(float frequency = ACS712_DEFAULT_FREQ, uint16_t cycles = 1); // returns mA // blocks < 1 ms float mA_DC(uint16_t samples = 1); // midPoint functions // set reference point (raw ADC) for both DC and AC uint16_t setMidPoint(uint16_t midPoint); uint16_t getMidPoint(); uint16_t incMidPoint(); uint16_t decMidPoint(); // Auto midPoint, assuming zero DC current or any AC current uint16_t autoMidPoint(float frequency = ACS712_DEFAULT_FREQ, uint16_t cycles = 1); // resets to half maxADC uint16_t resetMidPoint(); // Form Factor is also known as crest factor; // affects mA_AC() only, default sinus. void setFormFactor(float formFactor = ACS712_FF_SINUS); float getFormFactor(); // noise defaults 21 datasheet void setNoisemV(uint8_t noisemV = ACS712_DEFAULT_NOISE); uint8_t getNoisemV(); // enable/disable noiseSuppression for this measurement as needed. float mVNoiseLevel(float frequency = ACS712_DEFAULT_FREQ, uint16_t cycles = 1); // uses mA_peak2peak() void suppressNoise(bool flag); // Adjusting resolution AC and DC void setmVperAmp(float mVperAmpere); float getmVperAmp(); float getmAPerStep(); float getAmperePerStep(); // Frequency detection. // the minimal frequency determines the time to sample. float detectFrequency(float minimalFrequency = 40); void setMicrosAdjust(float factor = 1.0); float getMicrosAdjust(); // DEBUG uint16_t getMinimum(uint16_t milliSeconds = 20); uint16_t getMaximum(uint16_t milliSeconds = 20); private: uint8_t _pin; uint16_t _maxADC; float _mVperStep; float _formFactor; // peak2peak -> RMS float _mVperAmpere; float _mAPerStep; uint16_t _midPoint; uint8_t _noisemV; float _microsAdjust = 1.0; // 0.9986 bool _suppresNoise = false; }; // simulate analogRead() - develop only - // static int aRead(uint8_t pin) // { // float t = micros(); // float value = 515 + 50 * sin(t * PI / 180.0); // return value; // } // -- END OF FILE --