Pi Zero - Basic Buzzer/Audio

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I’m working on a project to use a Pi Zero to control a small remote-control Excavator. It is coming along nicely. I still need to add some LEDs and some simple audio. My question for this board is around the audio options.

I want the machine to have basically two or three sounds.

  1. An ‘engine’ rumble.
  2. A reverse ‘beep beep beep’
  3. Perhaps a few simple tunes (‘mighty machines’ or something).

I don’t need high quality audio, so I don’t want to add a powered speaker and build a headphone jack circuit. I have almost what I want by using a piezo buzzer, but the volume is low. Perhaps I could fix that with a power transistor, but I haven’t researched that yet.

I think this device:
https://core-electronics.com.au/gravity-digital-speaker-module.html
might be perfect, but it looks like it is designed for the arduino platform. Would this work on the Pi?
This would work, but at 20 bucks, it would be over-kill.
https://core-electronics.com.au/mini-external-usb-stereo-speaker.html
I can’t use a hat because I’m already using the Dark Water 640 motor driver hat.

Any advice?

Thanks.
-John
PS. Once I’m done, I’ll post my results and how-to videos.

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Hi John,

Sounds like a great project underway! If you are happy with the buzzer audio quality but are after some more volume, then perhaps it’s worth experimenting with a transistor to see if that helps. I am assuming a couple of things, such as the buzzer you are using is not being fully driven and/or you could use a higher voltage supply safely get more out of it. Consider this schematic with a NPN transistor, however, D1 replaced with the buzzer and R2 removed (and use 5V instead of 20V for buzzer power):

BNKri.png600×592 11.7 KB

Adding speaker grade audio to the PiZ is going to be around 10-20$ for a reliable device that has well-supported documentation. If you are after a quick-win, then I’d lean to the $20 USB speaker, it’s very popular for projects such as this:

https://core-electronics.com.au/mini-external-usb-stereo-speaker.html

2 Likes
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Thanks for the reply Graham!

I tried the amplifier, but it didn’t work very well. I ordered the mini external usb stereo speaker…

I think this will be overkill for this project, but let’s see how it goes.

Thanks again,

-John

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Done: http://convert-rc.blogspot.com.au/2017/12/digger-ps3-convert.html