Fork of the espurna firmware for `mhsw` switches
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

284 lines
8.8 KiB

// -----------------------------------------------------------------------------
// Dallas OneWire Sensor
// Uses OneWire library
// Copyright (C) 2017 by Xose Pérez <xose dot perez at gmail dot com>
// -----------------------------------------------------------------------------
#pragma once
#include "Arduino.h"
#include "BaseSensor.h"
#include <vector>
#include <OneWire.h>
#define DS_CHIP_DS18S20 0x10
#define DS_CHIP_DS1822 0x22
#define DS_CHIP_DS18B20 0x28
#define DS_CHIP_DS1825 0x3B
#define DS_PARASITE 1
#define DS_DISCONNECTED -127
#define DS_CMD_START_CONVERSION 0x44
#define DS_CMD_READ_SCRATCHPAD 0xBE
#define DS_ERROR_FAILED_RESET -2
#define DS_ERROR_FAILED_READ -3
class DallasSensor : public BaseSensor {
public:
// ---------------------------------------------------------------------
// Public
// ---------------------------------------------------------------------
DallasSensor(): BaseSensor() {
_sensor_id = SENSOR_DALLAS_ID;
}
// ---------------------------------------------------------------------
void setGPIO(unsigned char gpio) {
if (_gpio == gpio) return;
_gpio = gpio;
_dirty = true;
}
// ---------------------------------------------------------------------
unsigned char getGPIO() {
return _gpio;
}
// ---------------------------------------------------------------------
// Sensor API
// ---------------------------------------------------------------------
// Initialization method, must be idempotent
void begin() {
if (!_dirty) return;
_dirty = false;
_interval = SENSOR_READ_INTERVAL / 2;
// OneWire
if (_wire) delete _wire;
_wire = new OneWire(_gpio);
// Search devices
loadDevices();
// If no devices found check again pulling up the line
if (_count == 0) {
pinMode(_gpio, INPUT_PULLUP);
loadDevices();
}
}
// Loop-like method, call it in your main loop
void tick() {
static unsigned long last = 0;
if (millis() - last < _interval) return;
last = millis();
// Every second we either start a conversion or read the scratchpad
static bool conversion = true;
if (conversion) {
// Start conversion
_wire->reset();
_wire->skip();
_wire->write(DS_CMD_START_CONVERSION, DS_PARASITE);
} else {
// Read scratchpads
for (unsigned char index=0; index<_devices.size(); index++) {
// Read scratchpad
if (_wire->reset() == 0) {
_error = DS_ERROR_FAILED_RESET;
return;
}
_wire->select(_devices[index].address);
_wire->write(DS_CMD_READ_SCRATCHPAD);
uint8_t data[9];
for (unsigned char i = 0; i < 9; i++) {
data[i] = _wire->read();
}
#if false
Serial.printf("[DS18B20] Data = ");
for (unsigned char i = 0; i < 9; i++) {
Serial.printf("%02X ", data[i]);
}
Serial.printf(" CRC = %02X\n", OneWire::crc8(data, 8));
#endif
if (_wire->reset() != 1) {
_error = DS_ERROR_FAILED_READ;
return;
}
if (OneWire::crc8(data, 8) != data[8]) {
_error = SENSOR_ERROR_CRC;
return;
}
memcpy(_devices[index].data, data, 9);
}
}
conversion = !conversion;
}
// Descriptive name of the sensor
String description() {
char buffer[20];
snprintf(buffer, sizeof(buffer), "Dallas @ GPIO%d", _gpio);
return String(buffer);
}
// Descriptive name of the slot # index
String slot(unsigned char index) {
_error = SENSOR_ERROR_OK;
if (index < _count) {
char buffer[40];
uint8_t * address = _devices[index].address;
snprintf(buffer, sizeof(buffer), "%s (%02X%02X%02X%02X%02X%02X%02X%02X) @ GPIO%d",
chipAsString(index).c_str(),
address[0], address[1], address[2], address[3],
address[4], address[5], address[6], address[7],
_gpio
);
return String(buffer);
}
_error = SENSOR_ERROR_OUT_OF_RANGE;
return String();
}
// Type for slot # index
magnitude_t type(unsigned char index) {
_error = SENSOR_ERROR_OK;
if (index < _count) return MAGNITUDE_TEMPERATURE;
_error = SENSOR_ERROR_OUT_OF_RANGE;
return MAGNITUDE_NONE;
}
// Current value for slot # index
double value(unsigned char index) {
if (index >= _count) {
_error = SENSOR_ERROR_OUT_OF_RANGE;
return 0;
}
uint8_t * data = _devices[index].data;
// Registers
// byte 0: temperature LSB
// byte 1: temperature MSB
// byte 2: high alarm temp
// byte 3: low alarm temp
// byte 4: DS18S20: store for crc
// DS18B20 & DS1822: configuration register
// byte 5: internal use & crc
// byte 6: DS18S20: COUNT_REMAIN
// DS18B20 & DS1822: store for crc
// byte 7: DS18S20: COUNT_PER_C
// DS18B20 & DS1822: store for crc
// byte 8: SCRATCHPAD_CRC
int16_t raw = (data[1] << 8) | data[0];
if (chip(index) == DS_CHIP_DS18S20) {
raw = raw << 3; // 9 bit resolution default
if (data[7] == 0x10) {
raw = (raw & 0xFFF0) + 12 - data[6]; // "count remain" gives full 12 bit resolution
}
} else {
byte cfg = (data[4] & 0x60);
if (cfg == 0x00) raw = raw & ~7; // 9 bit res, 93.75 ms
else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
// 12 bit res, 750 ms
}
double value = (float) raw / 16.0;
if (value == DS_DISCONNECTED) {
_error = SENSOR_ERROR_CRC;
return 0;
}
_error = SENSOR_ERROR_OK;
return value;
}
protected:
// ---------------------------------------------------------------------
// Protected
// ---------------------------------------------------------------------
bool validateID(unsigned char id) {
return (id == DS_CHIP_DS18S20) || (id == DS_CHIP_DS18B20) || (id == DS_CHIP_DS1822) || (id == DS_CHIP_DS1825);
}
unsigned char chip(unsigned char index) {
if (index < _count) return _devices[index].address[0];
return 0;
}
String chipAsString(unsigned char index) {
unsigned char chip_id = chip(index);
if (chip_id == DS_CHIP_DS18S20) return String("DS18S20");
if (chip_id == DS_CHIP_DS18B20) return String("DS18B20");
if (chip_id == DS_CHIP_DS1822) return String("DS1822");
if (chip_id == DS_CHIP_DS1825) return String("DS1825");
return String("Unknown");
}
void loadDevices() {
uint8_t address[8];
_wire->reset();
_wire->reset_search();
while (_wire->search(address)) {
// Check CRC
if (_wire->crc8(address, 7) == address[7]) {
// Check ID
if (validateID(address[0])) {
ds_device_t device;
memcpy(device.address, address, 8);
_devices.push_back(device);
}
}
}
_count = _devices.size();
}
typedef struct {
uint8_t address[8];
uint8_t data[9];
} ds_device_t;
std::vector<ds_device_t> _devices;
unsigned char _gpio;
unsigned long _interval;
OneWire * _wire;
};