Fork of the espurna firmware for `mhsw` switches
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// -----------------------------------------------------------------------------
// HC-SR04 Ultrasonic sensor
// Copyright (C) 2018 by Xose Pérez <xose dot perez at gmail dot com>
// -----------------------------------------------------------------------------
#if SENSOR_SUPPORT && HCSR04_SUPPORT
#pragma once
#include "Arduino.h"
#include "BaseSensor.h"
class HCSR04Sensor : public BaseSensor {
public:
// ---------------------------------------------------------------------
// Public
// ---------------------------------------------------------------------
HCSR04Sensor(): BaseSensor() {
_count = 1;
_sensor_id = SENSOR_HCSR04_ID;
}
// ---------------------------------------------------------------------
void setEcho(unsigned char echo) {
_echo = echo;
}
void setTrigger(unsigned char trigger) {
_trigger = trigger;
}
// ---------------------------------------------------------------------
unsigned char getEcho() {
return _echo;
}
unsigned char getTrigger() {
return _trigger;
}
// ---------------------------------------------------------------------
// Sensor API
// ---------------------------------------------------------------------
// Initialization method, must be idempotent
void begin() {
pinMode(_echo, INPUT);
pinMode(_trigger, OUTPUT);
digitalWrite(_trigger, LOW);
_ready = true;
}
// Descriptive name of the sensor
String description() {
char buffer[24];
snprintf(buffer, sizeof(buffer), "HCSR04 @ GPIO(%u, %u)", _trigger, _echo);
return String(buffer);
}
// Descriptive name of the slot # index
String slot(unsigned char index) {
return description();
};
// Address of the sensor (it could be the GPIO or I2C address)
String address(unsigned char index) {
return String(_trigger);
}
// Type for slot # index
unsigned char type(unsigned char index) {
if (index == 0) return MAGNITUDE_DISTANCE;
return MAGNITUDE_NONE;
}
// Current value for slot # index
double value(unsigned char index) {
if (index == 0) {
// Trigger pulse
digitalWrite(_trigger, HIGH);
delayMicroseconds(10);
digitalWrite(_trigger, LOW);
// Wait for echo pulse low-high-low
while ( digitalRead(_echo) == 0 ) yield();
unsigned long start = micros();
while ( digitalRead(_echo) == 1 ) yield();
unsigned long travel_time = micros() - start;
// Assuming a speed of sound of 340m/s
// Dividing by 2 since it is a round trip
return 340.0 * (double) travel_time / 1000000.0 / 2;
}
return 0;
}
protected:
// ---------------------------------------------------------------------
// Protected
// ---------------------------------------------------------------------
unsigned char _trigger;
unsigned char _echo;
};
#endif // SENSOR_SUPPORT && HCSR04_SUPPORT