Hello Everybody, and Happy New Year to all.
Would you please help me with my small project? I have a DS18b20 temperature sensor to monitor the temperature of the boiler cylinder. The boiler shall stop heating the water at 60 C, so when it is 60 C, the main switch will automatically turn off. However, the water's temperature will keep rising between 63-65 C for a few minutes because the elements are still hot. Sometimes the main switch fails to stop and the water keeps heating up. Would you please help me develop the sketch to start the buzzer alarm only if the sensor temperature is above 60 C for more than 15 min? Thank you
// Include the libraries we need
#include <OneWire.h>
#include <DallasTemperature.h>
// Data wire is plugged into port 4 on the Arduino
#define ONE_WIRE_BUS 4
// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);
// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);
// arrays to hold device address
DeviceAddress insideThermometer;
void setup(void)
{
// start serial port
Serial.begin(9600);
Serial.println("Dallas Temperature IC Control Library Demo");
// locate devices on the bus
Serial.print("Locating devices...");
sensors.begin();
Serial.print("Found ");
Serial.print(sensors.getDeviceCount(), DEC);
Serial.println(" devices.");
// report parasite power requirements
Serial.print("Parasite power is: ");
if (sensors.isParasitePowerMode()) Serial.println("ON");
else Serial.println("OFF");
if (!sensors.getAddress(insideThermometer, 0)) Serial.println("Unable to find address for Device 0");
Serial.print("Device 0 Address: ");
printAddress(insideThermometer);
Serial.println();
sensors.setResolution(insideThermometer, 9);
Serial.print("Device 0 Resolution: ");
Serial.print(sensors.getResolution(insideThermometer), DEC);
Serial.println();
}
// function to print the temperature for a device
void printTemperature(DeviceAddress deviceAddress)
{
float tempC = sensors.getTempC(deviceAddress);
if(tempC == DEVICE_DISCONNECTED_C)
{
Serial.println("Error: Could not read temperature data");
return;
}
Serial.print("Temp C: ");
Serial.print(tempC);
Serial.print(" Temp F: ");
Serial.println(DallasTemperature::toFahrenheit(tempC)); // Converts tempC to Fahrenheit
}
/*
* Main function. It will request the tempC from the sensors and display on Serial.
*/
void loop(void)
{
// call sensors.requestTemperatures() to issue a global temperature
// request to all devices on the bus
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
// It responds almost immediately. Let's print out the data
printTemperature(insideThermometer); // Use a simple function to print out the data
}
// function to print a device address
void printAddress(DeviceAddress deviceAddress)
{
for (uint8_t i = 0; i < 8; i++)
{
if (deviceAddress[i] < 16) Serial.print("0");
Serial.print(deviceAddress[i], HEX);
}
}