The idea:
Monitor the temperature of coffee with WeMos D1 Mini microcontroller and MLX90614 infrared temperature sensor. Uses HC-SR04 ultrasonic sensor to detect if the coffee pot is in place or not.
Note: The HC-SR04 needs a logic level converter to work with WeMos D1 mini as the HC-SR04 is a 5V device and WeMos D1 mini GPIO ports are 3.3V
Parts needed:
- Wemos D1 Mini microcontroller
- MLX90614 infrared temperature sensor
- HC-SR04 ultrasonic sensor
The implementation:
Uses Firebase Real-time database to store measurements and Firebase Functions to provide an API to query the measurements.
The API is used by a Slack slash command.
Feature ideas:
- OTA update
Wemos D1 Mini pinout:
Wiring:
Wemos D1 Mini <-> MLX90614 infrared temperature sensor
D1 <-> SDL
3.3V <-> VCC
GND <-> GND
D2 <-> SDA
Wemos D1 Mini <-> HC-SR04 ultrasonic sensor
D6 <- [3.3V ~ logic level converter ~ 5 V]-> ECHO
D7 <- [3.3V ~ logic level converter ~ 5 V] -> TRIG