Fork of the espurna firmware for `mhsw` switches
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// -----------------------------------------------------------------------------
// SDS011 particulates sensor
// Based on: https://github.com/ricki-z/SDS011
//
// Uses SoftwareSerial library
// Copyright (C) 2018 by Lucas Pleß <hello at lucas-pless dot com>
// -----------------------------------------------------------------------------
#if SENSOR_SUPPORT && SDS011_SUPPORT
#pragma once
#include "Arduino.h"
#include "BaseSensor.h"
#include <SoftwareSerial.h>
class SDS011Sensor : public BaseSensor {
public:
// ---------------------------------------------------------------------
// Public
// ---------------------------------------------------------------------
SDS011Sensor(): BaseSensor() {
_count = 2;
_sensor_id = SENSOR_SDS011_ID;
}
~SDS011Sensor() {
if (_serial) delete _serial;
}
// ---------------------------------------------------------------------
void setRX(unsigned char pin_rx) {
if (_pin_rx == pin_rx) return;
_pin_rx = pin_rx;
_dirty = true;
}
void setTX(unsigned char pin_tx) {
if (_pin_tx == pin_tx) return;
_pin_tx = pin_tx;
_dirty = true;
}
// ---------------------------------------------------------------------
unsigned char getRX() {
return _pin_rx;
}
unsigned char getTX() {
return _pin_tx;
}
// ---------------------------------------------------------------------
// Sensor API
// ---------------------------------------------------------------------
// Initialization method, must be idempotent
void begin() {
if (!_dirty) return;
if (_serial) delete _serial;
_serial = new SoftwareSerial(_pin_rx, _pin_tx);
_serial->begin(9600);
_ready = true;
_dirty = false;
}
// Descriptive name of the sensor
String description() {
char buffer[28];
snprintf(buffer, sizeof(buffer), "SDS011 @ SwSerial(%u,%u)", _pin_rx, _pin_tx);
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) {
char buffer[6];
snprintf(buffer, sizeof(buffer), "%u:%u", _pin_rx, _pin_tx);
return String(buffer);
}
// Type for slot # index
unsigned char type(unsigned char index) {
if (index == 0) return MAGNITUDE_PM2dot5;
if (index == 1) return MAGNITUDE_PM10;
return MAGNITUDE_NONE;
}
void pre() {
_read();
}
// Current value for slot # index
double value(unsigned char index) {
if (index == 0) return _p2dot5;
if (index == 1) return _p10;
return 0;
}
protected:
// ---------------------------------------------------------------------
// Protected
// ---------------------------------------------------------------------
void _read() {
byte buffer;
int value;
int len = 0;
int pm10_serial = 0;
int pm25_serial = 0;
int checksum_is;
int checksum_ok = 0;
while ((_serial->available() > 0) && (_serial->available() >= (10-len))) {
buffer = _serial->read();
value = int(buffer);
switch (len) {
case (0): if (value != 170) { len = -1; }; break;
case (1): if (value != 192) { len = -1; }; break;
case (2): pm25_serial = value; checksum_is = value; break;
case (3): pm25_serial += (value << 8); checksum_is += value; break;
case (4): pm10_serial = value; checksum_is += value; break;
case (5): pm10_serial += (value << 8); checksum_is += value; break;
case (6): checksum_is += value; break;
case (7): checksum_is += value; break;
case (8): if (value == (checksum_is % 256)) { checksum_ok = 1; } else { len = -1; }; break;
case (9): if (value != 171) { len = -1; }; break;
}
len++;
if (len == 10) {
if(checksum_ok == 1) {
_p10 = (float)pm10_serial/10.0;
_p2dot5 = (float)pm25_serial/10.0;
len = 0; checksum_ok = 0; pm10_serial = 0.0; pm25_serial = 0.0; checksum_is = 0;
_error = SENSOR_ERROR_OK;
} else {
_error = SENSOR_ERROR_CRC;
}
}
yield();
}
}
double _p2dot5 = 0;
double _p10 = 0;
unsigned int _pin_rx;
unsigned int _pin_tx;
SoftwareSerial * _serial = NULL;
};
#endif // SENSOR_SUPPORT && SDS011_SUPPORT