Touch morse key
In a search on ebay, I came across a touch module based on a AT42QT1010 chip.
This module is approximately 32x22mm in size. Supply voltage is 1.8-5V. costs about 4 euros.
When touching the print , out becomes high.
There is also a "pad" connection. You can connect this to an external touch surface. (in my case the paddles)
These modules are very sensitive. They even detect a touch through 1cm thick glass.
I decided to make a cw paddle just for fun. I am not a cw-guy HI.
The manual of my transmitter showed that I have to switch a contact to ground.
So “out” had to be inverted. Dr google advised. Put a mosfet behind it.
I used a BS170.
The schematic looks like this:
The jack was replaced by a 3.5mm stereo cord.
The paddles are made from pcb board. I put them 15mm apart. You can adjust this according to your needs. I mounted them on a piece of experimental PCB.
The mosfet was soldered on the out and ground (gate and source) from te module.
The drain was connected to the audio cable.
The modules and battery holder were secured with double-sided tape.
The paddle was extensively tested by ON6WJ with an FT817 and works properly.
.jpg)