Adding a beeper/buzzer to a Teensy/TMK


26 May 2019, 20:01

Hi everyone,

I'm currently in the process of doing a Zenith Z-150 handwire/restoration and want to include the original built in beeper. There's a good chance I'd need some external circuitry to properly drive it as it might not be within the specifications of what a Teensy can drive. I'm wondering if anyone has done something similar and can show how they did it, primarily the code. Thanks!


26 May 2019, 23:13

The QMK firmware should have support for a buzzer, because the QMK Proton C microcontroller board (which is not based on an AVR microcontroller though) has a space for an optional buzzer.

However, there is a big different between an actual speaker (which you have to drive yourself), a piezoelectric buzzer (which drives itself from simple DC) and a beeper made to be driven by a specific signal. You would have to find out which type it is that your Zenith actually has.


26 May 2019, 23:25

Thanks, I will take a look at that. I think the beeper I have might require something to drive it, but I admittedly haven't looked into it much. I will check out the datasheet tomorrow. I'm more curious how I can get a signal from the Teensy whenever I press a key but I suppose the link you supplied covers that somewhere.

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26 May 2019, 23:59

You did not say which Teensy it is. Different versions have different MCUs.

Anyway I drive a piezo buzzer directly from an MCU pin and it works ok. I'm still using only about 1/3 of the pin current capacity.

Compute the maximum current your buzzer will need and if you are bellow the pin current rating (and the whole MCU is bellow its maximum current rating) then you are fine connecting it directly.

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27 May 2019, 09:08


27 May 2019, 10:04

Thanks everyone! I will report back at some point when the keyboard is finished (or when I've managed to mess it up and need help :lol: )

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