Make a CW key based on Arduino which uses capacitive touchpad buttons.
The sensors are two plates of a one-sided FR4 of 30x15mm in size are connected to the A0, A1 pins. The potentiometer connected to the A2 pin divides the supply voltage of 5V and determines the speed of the WPM transmission of symbols. The potentiometer connected to the A3 pin divides the 5V supply voltage and determines the frequency of the buzzer connected to the D10 terminal. Also, at the same time LED blinks in tact of morse.
Sketch in Arduino IDE ADCtouch