DS18B20.h

// SPDX-FileCopyrightText: AC SOFTWARE SP. Z O.O.
// SPDX-License-Identifier: GPL-2.0-or-later
 
#ifndef SRC_SUPLA_SENSOR_DS18B20_H_
#define SRC_SUPLA_SENSOR_DS18B20_H_
 
#include <Arduino.h>
#include <DallasTemperature.h>
#include <OneWire.h>
 
#include <supla/log_wrapper.h>
 
#include "supla/sensor/thermometer.h"
 
namespace Supla {
namespace Sensor {
 
class OneWireBus {
 public:
  explicit OneWireBus(uint8_t pinNumber)
      : pin(pinNumber), nextBus(nullptr), lastReadTime(0), oneWire(pinNumber) {
    SUPLA_LOG_DEBUG("Initializing OneWire bus at pin %d", pinNumber);
    sensors.setOneWire(&oneWire);
    sensors.begin();
    if (sensors.isParasitePowerMode()) {
      SUPLA_LOG_DEBUG("OneWire(pin %d) Parasite power is ON", pinNumber);
    } else {
      SUPLA_LOG_DEBUG("OneWire(pin %d) Parasite power is OFF", pinNumber);
    }
 
    SUPLA_LOG_DEBUG(
              "OneWire(pin %d) Found %d devices:",
              pinNumber,
              sensors.getDeviceCount());
 
    // report parasite power requirements
 
    DeviceAddress address;
    char strAddr[64];
    for (int i = 0; i < sensors.getDeviceCount(); i++) {
      if (!sensors.getAddress(address, i)) {
        SUPLA_LOG_DEBUG("Unable to find address for Device %d", i);
      } else {
        snprintf(
            strAddr, sizeof(strAddr),
            "{0x%02X, 0x%02X, 0x%02X, 0x%02X, 0x%02X, 0x%02X, 0x%02X, 0x%02X}",
            address[0],
            address[1],
            address[2],
            address[3],
            address[4],
            address[5],
            address[6],
            address[7]);
        SUPLA_LOG_DEBUG("Index %d - address %s", i, strAddr);
        sensors.setResolution(address, 12);
      }
      delay(0);
    }
    sensors.setWaitForConversion(true);
    sensors.requestTemperatures();
    sensors.setWaitForConversion(false);
  }
 
  int8_t getIndex(uint8_t *deviceAddress) {
    DeviceAddress address;
    for (int i = 0; i < sensors.getDeviceCount(); i++) {
      if (sensors.getAddress(address, i)) {
        bool found = true;
        for (int j = 0; j < 8; j++) {
          if (deviceAddress[j] != address[j]) {
            found = false;
          }
        }
        if (found) {
          return i;
        }
      }
    }
    return -1;
  }
 
  uint8_t pin;
  OneWireBus *nextBus;
  uint32_t lastReadTime;
  DallasTemperature sensors;
 
 protected:
  OneWire oneWire;
};
 
class DS18B20 : public Thermometer {
 public:
  explicit DS18B20(uint8_t pin, uint8_t *deviceAddress = nullptr) {
    OneWireBus *bus = oneWireBus;
    OneWireBus *prevBus = nullptr;
    address[0] = 0;
    lastValidValue = TEMPERATURE_NOT_AVAILABLE;
    retryCounter = 0;
 
    if (bus) {
      while (bus) {
        if (bus->pin == pin) {
          myBus = bus;
          break;
        }
        prevBus = bus;
        bus = bus->nextBus;
      }
    }
 
    // There is no OneWire bus created yet for this pin
    if (!bus) {
      SUPLA_LOG_DEBUG("Creating OneWire bus for pin: %d", pin);
      myBus = new OneWireBus(pin);
      if (prevBus) {
        prevBus->nextBus = myBus;
      } else {
        oneWireBus = myBus;
      }
    }
    if (deviceAddress == nullptr) {
      SUPLA_LOG_DEBUG(
                "Device address not provided. Using device from index 0");
    } else {
      memcpy(address, deviceAddress, 8);
    }
  }
 
  void iterateAlways() {
    if (millis() - myBus->lastReadTime > 10000) {
      myBus->sensors.requestTemperatures();
      myBus->lastReadTime = millis();
    }
    if (millis() - myBus->lastReadTime > 5000 &&
        (lastReadTime != myBus->lastReadTime)) {
      channel.setNewValue(getValue());
      lastReadTime = myBus->lastReadTime;
    }
  }
 
  double getValue() {
    double value = TEMPERATURE_NOT_AVAILABLE;
    if (address[0] == 0) {
      value = myBus->sensors.getTempCByIndex(0);
    } else {
      value = myBus->sensors.getTempC(address);
    }
 
    if (value == DEVICE_DISCONNECTED_C || value == 85.0) {
      value = TEMPERATURE_NOT_AVAILABLE;
    }
 
    if (value == TEMPERATURE_NOT_AVAILABLE) {
      retryCounter++;
      if (retryCounter > 3) {
        retryCounter = 0;
      } else {
        value = lastValidValue;
      }
    } else {
      retryCounter = 0;
    }
    lastValidValue = value;
 
    return value;
  }
 
  DallasTemperature &getHwSensors() {
    return myBus->sensors;
  }
 
 protected:
  static OneWireBus *oneWireBus;
  OneWireBus *myBus;
  DeviceAddress address;
  int8_t retryCounter;
  double lastValidValue;
};
 
OneWireBus *DS18B20::oneWireBus = nullptr;
 
};  // namespace Sensor
};  // namespace Supla
 
#endif  // SRC_SUPLA_SENSOR_DS18B20_H_