Sour Milk?!

We’ve had some issues at the office with milk going sour, usually over weekends.  This long weekend was extra bad as Tuesday morning we had to bin 7 x 4pint bottles of milk that had all turned to nasty smelling cheese over the course of the 3 day weekend.

It was suggested that we put a thermometer in the fridge, sure it’ll work, but it can only show you what the temp is NOW and not over time.  Soooo being a geek and very new to the world of Arduino, I knew I had to find a way.

Click here to see Photos of devices used

Enter the ESP8266 12-E and a DHT22 plus ThingSpeak.  I found the code I was looking for, thanks very much to “Chispa” over at #GoChispaGo.   The code only need a couple of minor tweaks plus a load of translating since his was in Spanish 😀

The code is pretty straightforward (says a guy that really doesn’t have any programming experience with Arduino’s).

Building the project was simple, the ESP8266 is powered by a USB cable and phone charger plugged into the wall and the DHT22 is plugged into 5vdc, ground and pin D4 on the ESP8266 board.

I got it working just fine though so I’m well pleased about that.

The data is logged to a chart: https://thingspeak.com/channels/321768

And the code used is as follows.

#include <DHT.h>
#include <ESP8266WiFi.h>
 
// Introducir a continuación tus datos de ThingSpeak y red WiFi
String apiKey = "YOUR THINGSPEAK API KEY";
const char* ssid = "your-SSID";
const char* password = "your-PASSWORD";
const char* server = "api.thingspeak.com";

// Time to sleep (in seconds):
//const int sleepTimeS = 60;

#define DHTPIN D4
#define DHTTYPE DHT22
 
DHT dht(DHTPIN, DHTTYPE);
WiFiClient client;
 
void setup() 
{
Serial.begin(115200);
delay(10);
dht.begin();
 
WiFi.begin(ssid, password);
 
Serial.println();
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
 
WiFi.begin(ssid, password);
 
while (WiFi.status() != WL_CONNECTED) 
{
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
 
}
 
void loop() 
{
delay(2000); 
float h = dht.readHumidity();
float t = dht.readTemperature();
if (isnan(h) || isnan(t)) 
{
Serial.println("DHT sensor reading failure !!!");
return;
}
 
if (client.connect(server,80)) {
String postStr = apiKey;
postStr +="&field1=";
postStr += String(t);
postStr +="&field2=";
postStr += String(h);
postStr += "\r\n\r\n";
 
client.print("POST /update HTTP/1.1\n");
client.print("Host: api.thingspeak.com\n");
client.print("Connection: close\n");
client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
client.print("Content-Type: application/x-www-form-urlencoded\n");
client.print("Content-Length: ");
client.print(postStr.length());
client.print("\n\n");
client.print(postStr);
 
Serial.print("Temperature: ");
Serial.print(t);
Serial.print("*C Humidity: ");
Serial.print(h);
Serial.print("%");
Serial.println("---->>>> Sent data to ThingSpeak");
}
client.stop();

//Sleep
//   Serial.println("ESP8266 in sleep mode");
//   ESP.deepSleep(sleepTimeS * 1000000,WAKE_RF_DEFAULT);

Serial.println("Waiting 60 seconds... ");
delay(60000);
}

Feel free to take the code and play away for your own needs.