This is a 16-key digital capacitive touch switch sensor, using the working mode of capacitive sensing trigger. Its communication is I2C communication, with simple and convenient wiring.
Onboard TTP229 capacitive 16-key touch sensor IC
Onboard power indicator
Working voltage: 2.4V-5.5V
Support to set the output mode, key output mode, the longest output time and fast / low power options
Size: 85mm * 55mm
After uploading the code to the UNO board, connect the UNO board to TTP229L module. Powered up, you can see the red LED on the module is on, then open the serial monitor, touch the key with finger and you can see the corresponding value as the figure shown below：