Control the freezers where I ferment and store my beer.
I started this project to learn Arduino. The initial code worked under Arduino UNO, later I discovered the cheap ESP8266 Module and started the work on it as an IoT device logging temperature readings on Thingspeak. Been using it for about a year, 10 months using the Arduino UNO version and 2 months with the ESP8266 WeMos D1 Board.
UsageDownload and setup the Arduino environment with the needed libraries and edit SSID, Wi-Fi, ThingSpeak Key, authentication username and password. Setup ThingSpeak:
The system is configured using a very basic html interface to turn freezers ON/OFF and to set the temperatures. The variables are saved to ESP8266 EEPROM. It can be accessed using device IP or mDNS name that is setup in the Arduino code.
SoftAP if no Wi-Fi is found
If the Wi-Fi connection is lost or not found, the system creates a SoftAP so you can manage it.
Over the air Firmware UpdateMakes updating software more easy. Just access /firmware login
and send the .bin
file compiled by the Arduino.
The normal pull-up resistor used for 5v would be a 4.7k resistor, I tried a 2.2k for this setup as recommended but was still getting some errors. The 1k resistor is the minimum recommended and was the only one that worked for this setup. I'm using 2 meter cable for each sensor.
Solid State RelaysI built them using the inductive model from this website. Used Google Translator to help me since I don't know french. The inductive model doesn't work with electronic freezers only old analog ones.
Any Solid State Relay that can handle your freezer power requirements will work. Also magnetic relay can work, but for magnetic charges they can be a problem sometimes. They must be activated with 3.3v from the WeMos Board.
Display Pinout
- ESP8266 Pin Number - WeMos Number
- CS #4 – D2
- DC #5 – D3
- SCK #14 – D5
- MISO #12 – D6
- MOSI #13 – D7
- RST - 3.3v
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