A wireless Temperature & Humidity sensor implemented to be placed inside a Cigar Humidor using the ESP32 micro-controller.
This is a micropython script for the ESP32 which gets the temperature and humidity readings from the DHT22 (AM2301) sensor and periodically logs it to a google sheets document via IFTTT.
The ESP32 then enters deep sleep mode for a defined period of time and then repeats the process.
The wifi capabilities of the ESP32 allows it to be placed in enclosed containers without damaging it.
The ESP32's deep sleep mode allows it to be powered by a battery for a long period of time.
Coding in micropython is arguably easier than in Arduino.
- Measures both temperature and humidity.
- Wireless (No drilling needed for cabling.)
- A relatively small device.
- Low powered (Replace batteries every month or so.)
- Log to google sheets (max of 2000 rows); No need to manage a server though.
Fun Fact: Cigars should be preserved somewhere around 70f at a relative humidity of around 70%.
The original guide uses a different sensor that includes a pressure sensor.
Guides on flashing micropython are available in the original guides website.
- an ESP32 board.
- a temperature/humidity sensor (this script uses the AM2301.)
- Some pin wires.
- a 4.7 ohm resistor.
- A usb cable for the board.
- Either a usb power bank or a 3.7v battery supply.
- Get a micropython IDE like upycraft.
- Get the latest micropython bin file.
- Install the ESP32 usb driver for your PC (Check your ESP32's specs, my driver was CP210X.)
- Flash the ESP32 with micropython using the IDE.
- Create a ifttt account (If this then that.)
- Create a ifttt applet for webhooks -> google sheets.
- Test the applet in the ifttt website.
- Create a file called boot.py and upload it to the ESP32.
- Make sure to change all parameters including the triggername for the IFTTT applet in the url request.