Our project is made of two main parts:

- a puff-suck sensor that translates the puffing-and-sucking actions into electrical signals,

- a micro-controller system (like an Arduino) that interprets the signals from the sensor into humanly readable text,commands or other information.

On this occasion, my (Cat's) part is the sensor, and Ana does the programming

I've been considering many ways to implement the mechanical part of the puff-suck sensor that would be suitable for Morse code input.

I've known Morse code for a long time and it was easy to imagine puffing-and-sucking it, but a few requirements have to be met to make it efficient (I have no idea if the same requirements are suitable for "normal" puff-suck switches):

- It has to have three states: puffed, sucked, neither

- It has to be able to switch fast between the states

- It has to work with relatively small volume of air

- It has to be able to keep a state for a while (up to a few seconds if slow) without effort

- Ideally it would provide some feedback

Next time I'll write about some options I considered and some I discarded, at least to start with.

Cat