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0.3.5 ACS712
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rob tillaart
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@ -1,7 +1,7 @@
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//
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// FILE: ACS712.cpp
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// AUTHOR: Rob Tillaart, Pete Thompson
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// VERSION: 0.3.4
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// VERSION: 0.3.5
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// DATE: 2020-08-02
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// PURPOSE: ACS712 library - current measurement
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// URL: https://github.com/RobTillaart/ACS712
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@ -26,7 +26,7 @@ ACS712::ACS712(uint8_t analogPin, float volts, uint16_t maxADC, float mVperAmper
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_midPoint = maxADC / 2;
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// default ADC is internal.
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setADC(_internalAnalog, volts, maxADC);
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setADC(NULL, volts, maxADC);
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}
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@ -42,16 +42,16 @@ float ACS712::mA_peak2peak(float frequency, uint16_t cycles)
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{
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int minimum, maximum;
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// Better than using midPoint
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minimum = maximum = _readADC(_pin);
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minimum = maximum = _analogRead(_pin);
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// find minimum and maximum
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uint32_t start = micros();
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while (micros() - start < period) // UNO ~180 samples...
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{
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int value = _readADC(_pin);
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int value = _analogRead(_pin);
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if (_suppresNoise) // average 2 samples.
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{
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value = (value + _readADC(_pin))/2;
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value = (value + _analogRead(_pin))/2;
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}
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// determine extremes
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if (value < minimum) minimum = value;
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@ -82,17 +82,17 @@ float ACS712::mA_AC(float frequency, uint16_t cycles)
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uint16_t zeros = 0;
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int _min, _max;
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_min = _max = _readADC(_pin);
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_min = _max = _analogRead(_pin);
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// find minimum and maximum and count the zero-level "percentage"
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uint32_t start = micros();
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while (micros() - start < period) // UNO ~180 samples...
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{
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samples++;
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int value = _readADC(_pin);
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int value = _analogRead(_pin);
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if (_suppresNoise) // average 2 samples.
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{
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value = (value + _readADC(_pin))/2;
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value = (value + _analogRead(_pin))/2;
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}
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// determine extremes
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if (value < _min) _min = value;
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@ -144,10 +144,10 @@ float ACS712::mA_AC_sampling(float frequency, uint16_t cycles)
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while (micros() - start < period)
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{
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samples++;
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int value = _readADC(_pin);
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int value = _analogRead(_pin);
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if (_suppresNoise) // average 2 samples.
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{
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value = (value + _readADC(_pin))/2;
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value = (value + _analogRead(_pin))/2;
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}
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float current = value - _midPoint;
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sumSquared += (current * current);
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@ -169,15 +169,15 @@ float ACS712::mA_AC_sampling(float frequency, uint16_t cycles)
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float ACS712::mA_DC(uint16_t cycles)
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{
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// read at least twice to stabilize the ADC
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_readADC(_pin);
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_analogRead(_pin);
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if (cycles == 0) cycles = 1;
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float sum = 0;
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for (uint16_t i = 0; i < cycles; i++)
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{
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int value = _readADC(_pin);
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int value = _analogRead(_pin);
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if (_suppresNoise) // average 2 samples.
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{
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value = (value + _readADC(_pin))/2;
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value = (value + _analogRead(_pin))/2;
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}
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sum += (value - _midPoint);
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}
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@ -233,7 +233,7 @@ uint16_t ACS712::autoMidPoint(float frequency, uint16_t cycles)
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uint32_t start = micros();
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while (micros() - start < twoPeriods)
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{
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uint16_t reading = _readADC(_pin);
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uint16_t reading = _analogRead(_pin);
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subTotal += reading;
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samples++;
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// Delaying prevents overflow
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@ -329,14 +329,14 @@ float ACS712::detectFrequency(float minimalFrequency)
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{
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int maximum = 0;
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int minimum = 0;
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maximum = minimum = _readADC(_pin);
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maximum = minimum = _analogRead(_pin);
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// determine maxima
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uint32_t timeOut = round(1000000.0 / minimalFrequency);
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uint32_t start = micros();
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while (micros() - start < timeOut)
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{
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int value = _readADC(_pin);
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int value = _analogRead(_pin);
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if (value > maximum) maximum = value;
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if (value < minimum) minimum = value;
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}
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@ -352,13 +352,13 @@ float ACS712::detectFrequency(float minimalFrequency)
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timeOut *= 10;
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start = micros();
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// casting to int to keep compiler happy.
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while ((int(_readADC(_pin)) > Q1) && ((micros() - start) < timeOut));
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while ((int(_readADC(_pin)) <= Q3) && ((micros() - start) < timeOut));
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while ((int(_analogRead(_pin)) > Q1) && ((micros() - start) < timeOut));
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while ((int(_analogRead(_pin)) <= Q3) && ((micros() - start) < timeOut));
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start = micros();
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for (int i = 0; i < 10; i++)
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{
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while ((int(_readADC(_pin)) > Q1) && ((micros() - start) < timeOut));
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while ((int(_readADC(_pin)) <= Q3) && ((micros() - start) < timeOut));
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while ((int(_analogRead(_pin)) > Q1) && ((micros() - start) < timeOut));
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while ((int(_analogRead(_pin)) <= Q3) && ((micros() - start) < timeOut));
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}
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uint32_t stop = micros();
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@ -386,13 +386,13 @@ float ACS712::getMicrosAdjust()
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// DEBUG
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uint16_t ACS712::getMinimum(uint16_t milliSeconds)
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{
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uint16_t minimum = _readADC(_pin);
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uint16_t minimum = _analogRead(_pin);
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// find minimum
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uint32_t start = millis();
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while (millis() - start < milliSeconds)
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{
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uint16_t value = _readADC(_pin);
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uint16_t value = _analogRead(_pin);
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if (value < minimum) minimum = value;
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}
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return minimum;
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@ -401,13 +401,13 @@ uint16_t ACS712::getMinimum(uint16_t milliSeconds)
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uint16_t ACS712::getMaximum(uint16_t milliSeconds)
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{
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uint16_t maximum = _readADC(_pin);
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uint16_t maximum = _analogRead(_pin);
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// find minimum
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uint32_t start = millis();
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while (millis() - start < milliSeconds)
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{
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uint16_t value = _readADC(_pin);
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uint16_t value = _analogRead(_pin);
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if (value > maximum) maximum = value;
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}
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return maximum;
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@ -425,5 +425,17 @@ void ACS712::setADC(uint16_t (* f)(uint8_t), float volts, uint16_t maxADC)
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}
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//////////////////////////////////////////////////////////////////////
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//
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// PRIVATE
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//
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uint16_t ACS712::_analogRead(uint8_t pin)
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{
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// if extern ADC is defined use it.
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if (_readADC != NULL) return _readADC(pin);
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return analogRead(pin);
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}
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// -- END OF FILE --
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@ -2,7 +2,7 @@
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//
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// FILE: ACS712.h
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// AUTHOR: Rob Tillaart, Pete Thompson
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// VERSION: 0.3.4
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// VERSION: 0.3.5
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// DATE: 2020-08-02
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// PURPOSE: ACS712 library - current measurement
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// URL: https://github.com/RobTillaart/ACS712
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@ -13,7 +13,7 @@
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#include "Arduino.h"
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#define ACS712_LIB_VERSION (F("0.3.4"))
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#define ACS712_LIB_VERSION (F("0.3.5"))
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// ACS712_FF_SINUS == 1.0/sqrt(2) == 0.5 * sqrt(2)
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@ -123,16 +123,10 @@ class ACS712
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// EXPERIMENTAL 0.3.4
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// supports up to 16 bits ADC.
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uint16_t (* _readADC)(uint8_t);
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uint16_t _analogRead(uint8_t pin);
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};
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// wrapper for internal analogRead()
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// solves platform specific casting.
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static uint16_t _internalAnalog(uint8_t pin)
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{
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return analogRead(pin);
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}
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// -- END OF FILE --
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@ -6,13 +6,19 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
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and this project adheres to [Semantic Versioning](http://semver.org/).
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## [0.3.5] - 2023-01-18
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- fix #33 failing build => issue 345 created @ arduino-ci
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- redo **setADC()**
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- allows reset to internal **analogRead()** too now.
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- update README.md
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## [0.3.4] - 2023-01-14
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- experimental
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- add **void setADC()** to use an external ADC for measurements.
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- add **static uint16_t internalAnalog(uint8_t p)** wrapping analogRead() - solves casting.
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- add example ACS712_20_DC_external_ADC.ino
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## [0.3.3] - 2023-01-03
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- update GitHub actions
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- update license
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@ -21,7 +21,7 @@
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"type": "git",
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"url": "https://github.com/RobTillaart/ACS712.git"
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},
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"version": "0.3.4",
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"version": "0.3.5",
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"license": "MIT",
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"frameworks": "arduino",
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"platforms": "*",
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@ -1,5 +1,5 @@
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name=ACS712
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version=0.3.4
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version=0.3.5
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author=Rob Tillaart <rob.tillaart@gmail.com>, Pete Thompson <pete.thompson@yahoo.com>
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maintainer=Rob Tillaart <rob.tillaart@gmail.com>
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sentence=ACS712 library for Arduino.
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@ -21,17 +21,17 @@ There are 4 core functions:
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- **float mA_peak2peak(frequency = 50, cycles = 1)**
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- **float mA_DC(cycles = 1)**
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- **float mA_AC(frequency = 50, cycles = 1)**
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- **float mA_AC_sampling(frequency = 50, cycles = 1)**
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- **float mA_AC_sampling(frequency = 50, cycles = 1)**
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The parameter cycles is used to do measure multiple cycles and average them.
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To measure DC current a single **analogRead()** with conversion math is
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sufficient to get a value.
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To measure DC current a single **analogRead()** with conversion math is
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sufficient to get a value.
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To stabilize the signal **analogRead()** is called at least twice.
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To measure AC current **a blocking loop for 20 milliseconds** (50 Hz, 1 cycle)
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is run to determine the peak to peak value which is converted to the RMS value.
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To convert the peak2peak value to RMS one need the so called crest or form factor.
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To measure AC current **a blocking loop for 20 milliseconds** (50 Hz, 1 cycle)
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is run to determine the peak to peak value which is converted to the RMS value.
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To convert the peak2peak value to RMS one need the so called crest or form factor.
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This factor depends heavily on the signal form, hence its name.
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For a perfect sinus the value is sqrt(2)/2 == 1/sqrt(2).
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See **Form factor** below.
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@ -40,7 +40,7 @@ The **mA_AC_sampling()** calculates the average of the sumSquared of many measur
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It should be used when the form factor is not known.
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Note to make precise measurements, the power supply of both the ACS712 and the ADC of
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the processor should be as stable as possible.
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the processor should be as stable as possible.
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That improves the stability of the midpoint and minimizes the noise.
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@ -58,7 +58,7 @@ mA LSB = (5000 mV / maxADC) / mVperA * 1000.0;
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mA LSB = (1000 * 5000 mV) / (maxADC * mVperA);
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```
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Although no 16 bit ADC built in are known, it indicates what resolution
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Although no 16 bit ADC built in are known, it indicates what resolution
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could be obtained with such an ADC. It triggered the thought for supporting
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external ADC's with this library or a derived version. See future.
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@ -73,7 +73,7 @@ The library is at least confirmed to work with the following boards:
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| Arduino UNO | 5.0V | 1024 | tested with Open-Smart ACS712 5 A breakout.
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| Arduino NANO | 5.0V | 1024 | #18
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| ESP32 | 3.3V | 4096 | #15
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| Promicro | 5.0V | 1024 | #15
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| Promicro | 5.0V | 1024 | #15
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Please let me know of other working platforms / processors.
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@ -85,7 +85,7 @@ Robodyn has a breakout for the ACS758 - 50 A. - See resolution below.
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This sensor has versions up to 200 Amps, so use with care!
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Allegromicro offers a lot of different current sensors, that might be compatible.
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These include bidirectional and unidirectional.
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These include bidirectional and unidirectional.
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The unidirectional seem to be for DC only.
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https://www.allegromicro.com/en/products/sense/current-sensor-ics/current-sensors-innovations
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@ -114,16 +114,16 @@ Not tested, but looks compatible - same formula as above
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#### Base
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- **ACS712(uint8_t analogPin, float volts = 5.0, uint16_t maxADC = 1023, float mVperAmpere = 100)** constructor.
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- **ACS712(uint8_t analogPin, float volts = 5.0, uint16_t maxADC = 1023, float mVperAmpere = 100)** constructor.
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It defaults a 20 A type sensor, which is defined by the default value of mVperAmpere. See table below.
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Volts is the voltage used by the (Arduino) internal ADC. maxADC is the maximum output of the internal ADC.
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The defaults are based upon an Arduino UNO, 10 bits ADC.
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These two ADC parameters are needed to calculate the voltage output of the ACS712 sensor.
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- **float mA_peak2peak(float frequency = 50, uint16_t cycles = 1)** blocks ~21 ms to sample a whole 50 or 60 Hz period.
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Returns the peak to peak current, can be used to determine form factor.
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The **mA_peak2peak()** can also be used to measure on a zero current line
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Returns the peak to peak current, can be used to determine form factor.
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The **mA_peak2peak()** can also be used to measure on a zero current line
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to get an indication of the lowest detectable current.
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Finally this function is used internally to detect the noiseLevel in mV on a zero current line.
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Finally this function is used internally to detect the noiseLevel in mV on a zero current line.
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- **float mA_AC(float frequency = 50, uint16_t cycles = 1)** blocks ~21 ms to sample a whole 50 or 60 Hz period.
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Note that a lower frequency, or more cycles, will increase the blocking period.
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The function returns the AC current in mA.
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@ -144,19 +144,19 @@ A negative value indicates the current flows in the opposite direction.
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#### Midpoint
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The midpoint is the (raw) zero-reference for all current measurements.
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It is defined in steps of the ADC and is typical around half the **maxADC** value defined
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It is defined in steps of the ADC and is typical around half the **maxADC** value defined
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in the constructor. So for a 10 bit ADC a number between 500..525 is most likely.
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Since 0.3.0 all midpoint functions return the actual midPoint.
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- **uint16_t setMidPoint(uint16_t midPoint)** sets midpoint for the ADC conversion.
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Parameter must be between 0 and maxADC/2, otherwise midpoint is not changed.
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- **uint16_t autoMidPoint(float frequency = 50, uint16_t cycles = 1)** Auto midPoint,
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assuming zero DC current or any AC current.
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- **uint16_t autoMidPoint(float frequency = 50, uint16_t cycles = 1)** Auto midPoint,
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assuming zero DC current or any AC current.
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The function takes the average of many measurements during one or more full cycles.
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Note the function therefore blocks for at least 2 periods.
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By increasing the number of cycles the function averages even more measurements,
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possibly resulting in a better midPoint. Idea is that noise will average out.
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Note the function therefore blocks for at least 2 periods.
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By increasing the number of cycles the function averages even more measurements,
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possibly resulting in a better midPoint. Idea is that noise will average out.
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This function is mandatory for measuring AC.
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- 0.2.2 frequencies other than 50 and 60 are supported.
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- 0.2.8 the parameter cycles allow to average over a number of cycles.
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@ -168,7 +168,7 @@ Will not decrease if midpoint equals 0.
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- **uint16_t resetMidPoint()** resets the midpoint to the initial value of maxADC / 2 as in the constructor.
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Since version 0.3.0 there is another way to determine the midPoint.
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One can use the two debug functions.
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One can use the two debug functions.
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(milliseconds > 20 to get at least a full cycle)
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- **uint16_t getMinimum(uint16_t milliSeconds = 20)**
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- **uint16_t getMaximum(uint16_t milliSeconds = 20)**
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@ -180,19 +180,19 @@ uint16_t midpoint = ACS.setMidPoint(ACS.getMinimum(20)/2 + ACS.getMaximum(20)/ 2
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```
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See - ACS712_20_AC_midPoint_compare.ino
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The ACS712 has a midPoint level that is specified as 0.5 \* VCC.
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So **autoMidPoint()** can help to detect voltage deviations for the ACS712.
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The ACS712 has a midPoint level that is specified as 0.5 \* VCC.
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So **autoMidPoint()** can help to detect voltage deviations for the ACS712.
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The library does not support this yet.
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#### Form factor
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#### Form factor
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The form factor is also known as the crest factor.
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The form factor is also known as the crest factor.
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It is only used for signals measured with **mA_AC()**.
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- **void setFormFactor(float formFactor = ACS712_FF_SINUS)** manually sets the form factor.
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Must typical be between 0.0 and 1.0, see constants below.
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- **float getFormFactor()** returns current form factor.
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- **float getFormFactor()** returns current form factor.
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The library has a number of predefined form factors:
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@ -204,7 +204,7 @@ The library has a number of predefined form factors:
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| ACS712_FF_SAWTOOTH | 1.0 / sqrt(3) | 0.577 | |
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It is important to measure the current with a calibrated multimeter
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and determine / verify the form factor of the signal.
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and determine / verify the form factor of the signal.
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This can help to improve the quality of your measurements.
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Please let me know if other crest factors need to be added.
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@ -222,15 +222,15 @@ See - ACS712_20_determine_form_factor.ino
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Default = 21 mV (datasheet)
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- **void setNoisemV(uint8_t noisemV = 21)** sets the noise level,
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- **void setNoisemV(uint8_t noisemV = 21)** sets the noise level,
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is used to determine zero level e.g. in the AC measurements with **mA_AC()**.
|
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- **uint8_t getNoisemV()** returns the set value.
|
||||
- **float mVNoiseLevel(float frequency, uint16_t cycles)** determines the mV of noise.
|
||||
Measurement should be taken when there is no AC/DC current or a constant DC current.
|
||||
Measurement should be taken when there is no AC/DC current or a constant DC current.
|
||||
The level will give a (not quantified yet) indication of the accuracy of the measurements.
|
||||
A first order indication can be made by comparing it to voltage / 2 of the constructor.
|
||||
|
||||
Noise on the signal can be reduced by using a low pass (RC) filter.
|
||||
Noise on the signal can be reduced by using a low pass (RC) filter.
|
||||
Version 0.3.1 includes experimental code to take two sample and average them.
|
||||
The idea is that ```((3 + 5)/2)^2 < (3^2 + 5^2)/2```
|
||||
|
||||
@ -242,7 +242,7 @@ software noise detection and suppression is needed.
|
||||
|
||||
#### mV per Ampere
|
||||
|
||||
Used for both for AC and DC measurements.
|
||||
Used for both for AC and DC measurements.
|
||||
Its value is defined in the constructor and depends on type sensor used.
|
||||
These functions allow to adjust this setting run-time.
|
||||
|
||||
@ -259,37 +259,71 @@ Experimental functionality for AC signal only!
|
||||
- **float detectFrequency(float minimalFrequency = 40)** Detect the frequency of the AC signal.
|
||||
- **void setMicrosAdjust(float factor = 1.0)** adjusts the timing of micros in **detectFrequency()**.
|
||||
Values are typical around 1.0 ± 1%
|
||||
- **float getMicrosAdjust()** returns the set factor.
|
||||
- **float getMicrosAdjust()** returns the set factor.
|
||||
|
||||
The minimum frequency of 40 Hz is used to sample for enough time to find the minimum and maximum
|
||||
for 50 and 60 Hz signals.
|
||||
for 50 and 60 Hz signals.
|
||||
Thereafter the signal is sampled 10 cycles to minimize the variation of the frequency.
|
||||
|
||||
The **microsAdjust()** is to adjust the timing of **micros()**.
|
||||
This function is only useful if one has a good reference source like a calibrated function generator
|
||||
to find the factor to adjust.
|
||||
The **microsAdjust()** is to adjust the timing of **micros()**.
|
||||
This function is only useful if one has a good reference source like a calibrated function generator
|
||||
to find the factor to adjust.
|
||||
Testing with my UNO I got a factor 0.9986.
|
||||
|
||||
Current version is experimental and not performance optimized.
|
||||
Current version is experimental and not performance optimized.
|
||||
|
||||
|
||||
#### setADC (experimental 0.3.4)
|
||||
|
||||
- **void setADC(uint16_t (\*)(uint8_t), float volts, uint16_t maxADC)** sets the ADC function and its parameters.
|
||||
Defaults the internal **analogRead()** by this wrapper in ACS712.h:
|
||||
- **void setADC(uint16_t (\*)(uint8_t), float volts, uint16_t maxADC)** sets the ADC function and the parameters of the used ADC.
|
||||
The library uses the internal **analogRead()** as default.
|
||||
Be sure to set the parameters of the ADC correctly.
|
||||
|
||||
The easiest way to implement an external ADC is to make a wrapper function as casting for
|
||||
function pointer is a no go area.
|
||||
|
||||
|
||||
```cpp
|
||||
static uint16_t _internalAnalog(uint8_t pin)
|
||||
// set to external ADC - 5 volts 12 bits
|
||||
ACS.setADC(myAnalogRead, 5.0, 4096);
|
||||
|
||||
...
|
||||
|
||||
uint16_t myAnalogRead(uint8_t pin)
|
||||
{
|
||||
return analogRead(pin);
|
||||
return MCP.read(pin); // assuming MCP is ADC object.
|
||||
}
|
||||
```
|
||||
|
||||
Be sure to set the parameters of the constructor correctly.
|
||||
|
||||
To reset to the internal ADC use **NULL** as function pointer.
|
||||
Be sure to set the parameters of the ADC correctly.
|
||||
|
||||
```cpp
|
||||
// reset to internal ADC - 5 volts 10 bits
|
||||
ACS.setADC(NULL, 5.0, 1023);
|
||||
```
|
||||
|
||||
- example ACS712_20_DC_external_ADC.ino
|
||||
- https://github.com/RobTillaart/ACS712/issues/31
|
||||
|
||||
|
||||
Note that the use of an external ADC should meet certain performance requirements,
|
||||
especially for measuring **ma-AC()**.
|
||||
To 'catch' the peaks well enough one needs at least 2 samples per millisecond
|
||||
for a 60 Hz signal.
|
||||
|
||||
The 16 bit I2C **ADS1115** in continuous mode gives max 0.8 samples per millisecond.
|
||||
This will work perfect for high resolution **mA-DC()** but is not fast enough for
|
||||
doing **mA-AC()**.
|
||||
|
||||
The SPI based **MCP3202** ao can do up to 100 samples per millisecond at 12 bit.
|
||||
These ADC's are perfect both **mA-DC()** and **mA-AC()**.
|
||||
|
||||
- https://github.com/RobTillaart/ADS1X15
|
||||
- https://github.com/RobTillaart/MCP_ADC
|
||||
|
||||
|
||||
## Voltage divider
|
||||
|
||||
As per issue #15 in which an ACS712 was connected via a voltage divider to the ADC of an ESP32.
|
||||
@ -302,16 +336,16 @@ ACS712 ----[ R1 ]----o----[ R2 ]---- GND
|
||||
ADC of processor
|
||||
```
|
||||
|
||||
The voltage divider gave an error of about a factor 2 as all voltages were divided,
|
||||
The voltage divider gave an error of about a factor 2 as all voltages were divided,
|
||||
including the "offset" from the **midPoint** zero current level.
|
||||
|
||||
By adjusting the mV per Ampere with **setmVperAmp(float mva)** the readings can be corrected
|
||||
By adjusting the mV per Ampere with **setmVperAmp(float mva)** the readings can be corrected
|
||||
for this "voltage divider effect".
|
||||
|
||||
|
||||
#### Examples:
|
||||
|
||||
For a 20 A type sensor, 100 mV/A would be the normal value.
|
||||
For a 20 A type sensor, 100 mV/A would be the normal value.
|
||||
After using a voltage divider one need to adjust the mVperAmp.
|
||||
|
||||
| R1 (ACS) | R2 (GND) | voltage factor | mVperAmp corrected |
|
||||
@ -328,11 +362,12 @@ After using a voltage divider one need to adjust the mVperAmp.
|
||||
|
||||
(to be tested)
|
||||
|
||||
To detect that the ACS712 is disconnected from the ADC one could connect the
|
||||
To detect that the ACS712 is disconnected from the ADC one could connect the
|
||||
analog pin via a pull-down to GND. A pull-up to VCC is also possible.
|
||||
Choose the solution that fits your project best. (Think safety).
|
||||
|
||||
**mA_DC()** and **mA_AC_sampling()** will report HIGH values (Out of range) when the ACS712 is disconnected.
|
||||
**mA_DC()** and **mA_AC_sampling()** will report HIGH values (Out of range) when
|
||||
the ACS712 is disconnected.
|
||||
The other - peak2peak based functions - will see this as zero current (min == max).
|
||||
|
||||
Schema with PULL-UP.
|
||||
@ -362,35 +397,26 @@ The examples show the basic working of the functions.
|
||||
#### Should - 0.3.x
|
||||
|
||||
- investigate noise suppression #21 (0.3.1 and later)
|
||||
- investigate blocking calls:
|
||||
- **mA_AC()** blocks for about 20 ms at 50 Hz.
|
||||
This might affect task scheduling on a ESP32. Needs to be investigated.
|
||||
Probably need a separate thread that wakes up when new analogRead is available?
|
||||
- RTOS specific class?
|
||||
- **detectFrequency(float)** blocks pretty long.
|
||||
|
||||
|
||||
#### Could
|
||||
|
||||
- merge **mA_AC()** and **mA_AC_sampling()** into one. (0.4.0)
|
||||
- or remove - depreciate - the worst one
|
||||
- investigate blocking calls:
|
||||
- **mA_AC()** blocks for about 20 ms at 50 Hz.
|
||||
This might affect task scheduling on a ESP32. Needs to be investigated.
|
||||
Probably need a separate thread that wakes up when new analogRead is available?
|
||||
- RTOS specific class?
|
||||
- **detectFrequency(float)** blocks pretty long.
|
||||
- other set functions also a range check?
|
||||
- split the readme.md in multiple documents?
|
||||
- which?
|
||||
- add range check to (all) set functions?
|
||||
|
||||
|
||||
#### Won't
|
||||
#### Won't (unless requested)
|
||||
|
||||
- external analogue read support? separate class!
|
||||
- after this one stabilized.
|
||||
- ACS712X class with external ADC ( 16 or even 24 bit)
|
||||
- keep interface alike?
|
||||
- are these fast enough for e.g. 60 Hz (100 samples in 16 millis?)
|
||||
- **ADS1115** in continuous mode ==> 0.8 samples per millisecond at 16 bit Ideal for **mA-DC()**
|
||||
- **MCP3202** SPI interface ==> up to 100 samples per millisecond !! at 12 bit. Perfect.
|
||||
- investigate support for micro-Amperes. **ACS.uA_DC()**
|
||||
- need a very stable voltage
|
||||
- needs a 24 bit ADC
|
||||
- need a very stable voltage
|
||||
- needs a 24 bit ADC
|
||||
- default noise is already ~21mV...
|
||||
- => not feasible in normal setup.
|
||||
- Should the FormFactor not be just a parameter of **mA_AC()**
|
||||
@ -400,4 +426,8 @@ The examples show the basic working of the functions.
|
||||
- midPoint can be a float so it can be set more exact.
|
||||
- extra precision is max half bit = smaller than noise?
|
||||
- math will be slower during sampling (UNO)
|
||||
- split the readme.md in multiple documents?
|
||||
- which?
|
||||
- setADC() to support > 16 bit?
|
||||
- uint32_t performance penalty?
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user