thethings.iO
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Monitor fridge with Arduino MKR1000 and thethings.iO

To assure that your beer (and other) beverages are at a cool temperature, today we show you how to remotely monitor your fridge!

BeginnerFull instructions provided1 hour4,062
Monitor fridge with Arduino MKR1000 and thethings.iO

Things used in this project

Hardware components

Arduino MKR1000
Arduino MKR1000
×1
Temperature sensor DS18B20
×1
Jumper wires (generic)
Jumper wires (generic)
×3

Hand tools and fabrication machines

Soldering iron (generic)
Soldering iron (generic)

Story

Read more

Schematics

Schematic

Code

Fridge monitor sketch

Arduino
This is a sketch for using the temperature sensor DS18B20 with the Arduino MKR1000 in order to send data to thethings.iO
#include <WiFi101.h>
#include <WiFiClient.h>
#include <OneWire.h>

#include <thethingsiO_mkr1000.h>

OneWire  ds(2);

#define WIFI_AP "YOUR ESSID HERE
#define WIFI_PWD "YOUR PASSWORD HERE"

int status = -1;
int millis_start;

#define TOKEN "YOUR TOKEN HERE"


thethingsiOWiFi thing(TOKEN);


void setup(void) {
  millis_start = millis();
  Serial.begin(115200);
  startWifi();
}

void loop(void) {
  byte i;
  byte present = 0;
  byte type_s;
  byte data[12];
  byte addr[8];
  float celsius, fahrenheit;
  
  if ( !ds.search(addr)) {
    Serial.println("No more addresses.");
    Serial.println();
    ds.reset_search();
    delay(250);
    return;
  }
  
  Serial.print("ROM =");
  for( i = 0; i < 8; i++) {
    Serial.write(' ');
    Serial.print(addr[i], HEX);
  }

  if (OneWire::crc8(addr, 7) != addr[7]) {
      Serial.println("CRC is not valid!");
      return;
  }
  Serial.println();
 
  // the first ROM byte indicates which chip
  switch (addr[0]) {
    case 0x10:
      Serial.println("  Chip = DS18S20");  // or old DS1820
      type_s = 1;
      break;
    case 0x28:
      Serial.println("  Chip = DS18B20");
      type_s = 0;
      break;
    case 0x22:
      Serial.println("  Chip = DS1822");
      type_s = 0;
      break;
    default:
      Serial.println("Device is not a DS18x20 family device.");
      return;
  } 

  ds.reset();
  ds.select(addr);
  ds.write(0x44, 1);        // start conversion, with parasite power on at the end
  
  delay(1000);     // maybe 750ms is enough, maybe not
  // we might do a ds.depower() here, but the reset will take care of it.
  
  present = ds.reset();
  ds.select(addr);    
  ds.write(0xBE);         // Read Scratchpad

  Serial.print("  Data = ");
  Serial.print(present, HEX);
  Serial.print(" ");
  for ( i = 0; i < 9; i++) {           // we need 9 bytes
    data[i] = ds.read();
    Serial.print(data[i], HEX);
    Serial.print(" ");
  }
  Serial.print(" CRC=");
  Serial.print(OneWire::crc8(data, 8), HEX);
  Serial.println();

  // Convert the data to actual temperature
  // because the result is a 16 bit signed integer, it should
  // be stored to an "int16_t" type, which is always 16 bits
  // even when compiled on a 32 bit processor.
  int16_t raw = (data[1] << 8) | data[0];
  if (type_s) {
    raw = raw << 3; // 9 bit resolution default
    if (data[7] == 0x10) {
      // "count remain" gives full 12 bit resolution
      raw = (raw & 0xFFF0) + 12 - data[6];
    }
  } else {
    byte cfg = (data[4] & 0x60);
    // at lower res, the low bits are undefined, so let's zero them
    if (cfg == 0x00) raw = raw & ~7;  // 9 bit resolution, 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
    //// default is 12 bit resolution, 750 ms conversion time
  }
  celsius = (float)raw / 16.0;
  fahrenheit = celsius * 1.8 + 32.0;
  Serial.print("  Temperature = ");
  Serial.print(celsius);
  Serial.print(" Celsius, ");
  Serial.print(fahrenheit);
  Serial.println(" Fahrenheit");
  if (millis() >= millis_start + 10000){
    thing.addValue("Temperature", celsius);
    thing.send();
    millis_start = millis();
  }
}

void startWifi(){
  Serial.println("Connecting MKR1000 to network...");
//  WiFi.begin();
   // attempt to connect to Wifi network:
  while ( status != WL_CONNECTED ) {
    Serial.print("Attempting to connect to WPA SSID: ");
    Serial.println(WIFI_AP);
    WiFi.begin(WIFI_AP, WIFI_PWD);
    // wait 10 seconds for connection:
    delay(10000);
    status = WiFi.status();
  }
}

Credits

thethings.iO

thethings.iO

6 projects • 18 followers
thethings.iO is the most simple enterprise IoT platform. We help businesses (and individuals) to connect your devices to the Internet.

Comments

Related channels and tags
  • Arduino
  • Environmental Sensing
  • Food & Drinks
  • Home Automation
  • Sensors