89 lines
2.1 KiB
C++
89 lines
2.1 KiB
C++
/**
|
|
* @file analog_input.h
|
|
* @author Adam Wonak (https://github.com/awonak)
|
|
* @brief Class for interacting with analog inputs.
|
|
* @version 0.1
|
|
* @date 2025-05-23
|
|
*
|
|
* @copyright MIT - (c) 2025 - Adam Wonak - adam.wonak@gmail.com
|
|
*
|
|
*/
|
|
#ifndef ANALOG_INPUT_H
|
|
#define ANALOG_INPUT_H
|
|
|
|
const int MAX_INPUT = (1 << 10) - 1; // Max 10 bit analog read resolution.
|
|
|
|
// estimated default calibration value
|
|
const int CALIBRATED_LOW = -566;
|
|
const int CALIBRATED_HIGH = 512;
|
|
|
|
class AnalogInput {
|
|
public:
|
|
AnalogInput() {}
|
|
~AnalogInput() {}
|
|
|
|
/**
|
|
* Initializes a analog input object.
|
|
*
|
|
* @param pin gpio pin for the analog input.
|
|
*/
|
|
void Init(uint8_t pin) {
|
|
pinMode(pin, INPUT);
|
|
pin_ = pin;
|
|
}
|
|
|
|
/**
|
|
* Read the value of the analog input and set instance state.
|
|
*
|
|
*/
|
|
void Process() {
|
|
old_read_ = read_;
|
|
int raw = analogRead(pin_);
|
|
read_ = map(raw, 0, MAX_INPUT, low_, high_);
|
|
read_ = constrain(read_ - offset_, -512, 512);
|
|
if (inverted_) read_ = -read_;
|
|
}
|
|
|
|
// Set calibration values.
|
|
|
|
void AdjustCalibrationLow(int amount) { low_ += amount; }
|
|
|
|
void AdjustCalibrationHigh(int amount) { high_ += amount; }
|
|
|
|
void SetOffset(float percent) { offset_ = -(percent)*512; }
|
|
|
|
void SetAttenuation(float percent) {
|
|
low_ = abs(percent) * CALIBRATED_LOW;
|
|
high_ = abs(percent) * CALIBRATED_HIGH;
|
|
inverted_ = percent < 0;
|
|
}
|
|
|
|
/**
|
|
* Get the current value of the analog input within a range of +/-512.
|
|
*
|
|
* @return read value within a range of +/-512.
|
|
*
|
|
*/
|
|
inline int16_t Read() { return read_; }
|
|
|
|
/**
|
|
* Return the analog read value as voltage.
|
|
*
|
|
* @return A float representing the voltage (-5.0 to +5.0).
|
|
*
|
|
*/
|
|
inline float Voltage() { return ((read_ / 512.0) * 5.0); }
|
|
|
|
private:
|
|
uint8_t pin_;
|
|
int16_t read_;
|
|
uint16_t old_read_;
|
|
// calibration values.
|
|
int offset_ = 0;
|
|
int low_ = CALIBRATED_LOW;
|
|
int high_ = CALIBRATED_HIGH;
|
|
bool inverted_ = false;
|
|
};
|
|
|
|
#endif
|