• 12-key touch panel based on ESP8266 and MPR121

12-key touch panel based on ESP8266 and MPR121

Here we come to talk about a development we have been working in the last months. This is an inexpensive WiFi touch panel based on the popular ESP8266 SoC and the powerful MPR121 capacitive touch controller. This board also includes a SI7021 temperature&humidity sensor, a piezoelectric buzzer, which can be used to add some press feedback, a driver for a WS2812 addressable RGB LED string and even an infrared port to maybe control a TV or air conditioner equipment. UART and I2C pins are exposed for further applications and we are currently modifying the design to expose also the rest of pins.


The board  needs to be powered from an external 5VDC power supply and, like any other ESP8266-based board, it can be programmed via USB from the Arduino IDE. The touch panel includes an on-board FTDI chip and microUSB connector so you can plug this board directly to a computer.

We have also developed an application that transmits temperature and humidity readings and tactile button detections via MQTT. Thus, this circuit can be used as a tactile wall or table mounting device to control things via MQTT. Since it reads ambiance temperature and humidity, this device can act as a complete room controller. It can be used to drive RGB LED’s and external relays or simply connect to any external PIR detector through one of the available IO pins.

The following a a short video quickly showing the touch panel transmitting MQTT packets whenever a tactile button is touched.

This product is still under final development so we would welcome any suggestion or idea that helps us make this product even more interesting. Thanks for your time!



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