Software to program the Arduino PLC

Lista de dispositivos conectados

The sketch lists the devices connected to the OneWire pin and shows their address. It also shows a note when the device is not a DS18xx device supported by the library.

#include <OneWire.h>
#include <DallasTemperature.h>

#define ADDR_LEN 8
#define PIN 2

OneWire oneWire(PIN);
DallasTemperature sensors(&oneWire);

////////////////////////////////////////////////////////////////////////////////////////////////////
void setup() {
  Serial.begin(9600L);
  Serial.println("ds18xx-list-devices started");
}

////////////////////////////////////////////////////////////////////////////////////////////////////
void loop() {
  Serial.println("----------------------------------------------------");

sensors.begin();

int deviceCount = sensors.getDeviceCount();
  Serial.print("Devices: ");
  Serial.println(deviceCount);

int ds18Count = sensors.getDS18Count();
  Serial.print("DS18xx devices: ");
  Serial.println(ds18Count);

uint8_t address[ADDR_LEN];
  for (int i = 0; i < deviceCount; ++i) {
    if (sensors.getAddress(address, i)) {
      Serial.print("Address: ");
      printAddress(address);
    }
  }
  delay(5000);
}

////////////////////////////////////////////////////////////////////////////////////////////////////
void printAddress(const uint8_t *address) {
  for (int i = 0; i < ADDR_LEN; ++i) {
    if (i > 0) {
      Serial.print('-');
    }
    if (address[i] < 0x10) {
      Serial.print('0');
    }
    Serial.print(address[i], HEX);
  }
  if (!sensors.validFamily(address)) {
    Serial.print(" (not supported)");
  }
  Serial.println();
}

Controlar el calentador en función de las lecturas de temperatura

El sketch obtiene el sensor de temperatura utilizando la biblioteca y luego lee periódicamente su temperatura.Cuando la temperatura es más fría que el punto de ajuste de temperatura, activa la salida Q0.0 para encender el calentador.

#include <DallasTemperature.h>
#define TEMP_SET_POINT 25      // Celsius
#define TEMP_READ_PERIOD 1000  // ms
#define TEMP_RESOLUTION 12     // bits
#define ONEWIRE_PIN 2          // Pin for the OneWire
#define HEATER_PIN Q0_0        // Digital Output pin to ON the heater

Not configurable constants
#define INVALID_SENSOR_INDEX 0xff
#define INVALID_TEMP 0x7fff
#define ADDRESS_LEN 8 // bytes

OneWire oneWire(ONEWIRE_PIN);              
DallasTemperature sensors(&oneWire);    
uint8_t tempIndex = INVALID_SENSOR_INDEX;
double temp = INVALID_TEMP;

////////////////////////////////////////////////////////////////////////////////////////////////////

void setup() {
  Serial.begin(9600L);
  Serial.println("ds18xx-temp-control started");
  initTempSensor();
}
////////////////////////////////////////////////////////////////////////////////////////////////////

void loop() {
  updateTemp();
  updateHeater();
}

////////////////////////////////////////////////////////////////////////////////////////////////////

void printAddress(const uint8_t *address) {
  for (uint8_t i = 0; i < ADDRESS_LEN; ++i) {
    if (i > 0) {
      Serial.print('-');
    }
    if (address[i] < 0x10) {
      Serial.print('0');
    }
    Serial.print(address[i], HEX);
  }
}

////////////////////////////////////////////////////////////////////////////////////////////////////

void initTempSensor() {
  // Begin sensors library
  sensors.begin();
  // Get temperature sensor
  uint8_t address[ADDRESS_LEN];
  uint8_t numDevices = sensors.getDeviceCount();   //number of devices connected
  for (uint8_t i = 0; i < numDevices; ++i) {       //loop for check all the devices connected
    if (sensors.getAddress(address, i)) {          //verification of correct address
      if (sensors.validFamily(address)) {          //verification of valid family
        tempIndex = i;                             //tempIndex different from INVALID_SENSOR_INDEX, flag
        Serial.print("Sensor address: ");
        printAddress(address);
        Serial.print(" (");
        Serial.print(tempIndex);
        Serial.print(")");
        Serial.println();
        break;
      }
    }
  }
  // Set sensors parameters
  sensors.setResolution(TEMP_RESOLUTION);        //This temperature resolution is of 12bits
}

////////////////////////////////////////////////////////////////////////////////////////////////////

void updateTemp() {
  static uint32_t lastUpdate = millis();
  if (tempIndex == INVALID_SENSOR_INDEX) {      //If the sensor index is invalid, we initialize the temperature sensor again.
    initTempSensor();                       
  } 
  else {                                       //If it is correct, we read the actual temperature from the sensor
    if (millis() - lastUpdate > TEMP_READ_PERIOD) {
      if (sensors.requestTemperaturesByIndex(tempIndex)) {
        temp = sensors.getTempCByIndex(tempIndex);
      }
    }
  }
}

////////////////////////////////////////////////////////////////////////////////////////////////////
void updateHeater() {                         //Function that controls the heater, it compares the temperature with the set point in order to activate or not the digital output.
  static double lastTemp = INVALID_TEMP;
  if (lastTemp != temp) {
    digitalWrite(HEATER_PIN, temp < TEMP_SET_POINT ? HIGH : LOW);
    lastTemp = temp;
  }
}