i’m an aspiring trumpet player and i thought about how cool it’d be to be able to “play” trumpet on the pokitto; Not particularly playing actual music but practicing my tabs;

Simply put: I can easily wire 3 “pistons” together on a rig similar to a trumpet system. Much like certain practice apps you would show a note on the pokitto screen where the “player” would have to press the right pistons to play said note…or no pistons at all as is needed for certain notes…
I haven’t got the slightest clue about programming though…at all…not even remotely.


I didn’t quite understand. Do you want a mechanical system to press the valves or just a system to show which notes are the result of pressing the valves?

If it is the latter, I can easily help you out because Tuomo plays the trumpet (and plays it rather well actually)

Does it have to be pistons or would a normal button suffice?

I’ve never come across any ‘pistons’ used as hardware input.

I have no clue how a trumpet works, but if the ‘pistons’ give different sounds depending on how far down they’re pressed then a button that gives out an analogue output depending on how far down it’s pressed should work.

Buttons would be good tbh but the piston system looks more trumpetlike…

@Jonne: The goal would be to learn the notes so you’d have to press down the notes your pokitto shows. ie: Pokitto shows a Mi so you’d have to press down on piston/button 1&2. Easy level would give you more time to press down on the buttons but as you get further the time to press down could shorten so you’d have to be faster.

The goal; obviously to learn the notes as you read them on paper. Tuomo probably understands what i mean if he plays trumpet :wink:

You could eventually build in how long you’d have to hold down to play a certain note because not all notes are equally long.

If I recall correctly any trumpet does feature only 3 “buttons”, so you could control them with 3 servomotors like SG90 (MG90 would be better though, I don’t think the trumpet buttons/pistons are THAT easy to press…).

Roughly sketching an idea, you would have to:
1 - Figure out where to position the servos, how to attach them so they don’t move after every action they do, and in a way you could possibly operate right after, without having them in the way;

2 - Calculate, basing on the chosen position, the relation between rotational position of the servos and vertical position of the trumpet piston; shouldn’t be too hard, I think you could compare it with a generic “CAM - PISTON” mechanism

  • 2a - Eventually restart from 1 if you find out that the chosen position isn’t optimal

3 - Wire the servos up to Pokitto (a) , OR to a separate MCU (b) (like an Attiny,an Atmega…) which can talk to the Pokitto via eg. I2C,UART…

  • 3a - No other components needed, no protocol overhead,etc… BUT, I’m not sure whether it’s possible to configure 3 PWM timers on the available Pokitto pins (if it’s possible, it shouldn’t be too hard though), and also you’d have to wire up a separate supply for the servos because they eat up A LOT of current, more than what the Pokitto can give
  • 3b - Involves just the effort to develop a simple I2c protocol, yeah it’s more components but not that many, still have the need to get a separate supply tho