Buzzer on the Matrix Voice Pins

Hello there,

does anyone has experience in using an active/passive buzzer on the GPIO Pins of the Matrix Voice Standard? I want to play 8 bit sounds, which could be accomplished with the RPi.GPIO library. More specific, i want to fork this repo https://github.com/gumslone/raspi_buzzer_player/blob/db2c55806185e23a5f478bfa899f9bae9b465697/buzzer_player.py#L575

  • How could this be accomplished using the Matrix Voice Standard?
  • In general, which GPIOs could be used to play sounds with the buzzer and the Matrix Lite?
  • Is it possible to use the library RPi.GPIO in order to control the pins on the Matrix Voice?

@Samreen

Thank very much :grinning:

Hey @Mondmonarch,

I’ve never tried but I just Googled how buzzers work.

Option 1

It seems active buzzers use DC high low so you can just use our MATRIX Lite JS or Py GPIO libraries and use the digital output functions with the MATRIX Voice GPIO expansion pins.

You can use any of the digital pins 0-15 for that.

I think passive buzzers can be controlled via PWM on a digital pin, judging from what the tone function in Arduino does, so you should also be able to use MATRIX Lite for this - the PWM function.

Option 2

It is possible to use Raspberry Pi GPIO pins through the MATRIX Voice expansion GPIOs, it takes some simple FPGA re-routing as shown in the Hackster guide here. Once you expose some of the RPi pins, you should be able to use any RPi GPIO libraries to control buzzers.

Edit: Just realized you provided a GitHub repo link, I think you may be able to get the same functionality with some edits to that code using MATRIX Lite Py - I think it’s worth a shot. Otherwise, you can try option 2!

Best,
Samreen