Synth Speaker o24 and Arduino


I have a circuit Power–Cloudbit–Arduino–MP3 Player–Synth Speaker. The circuit functions as designed (gives audible alarm when the ISS is viewable overhead), but the synth speaker puts out noise all the time.

Is there anyway to eliminate this?

Kind regards,


Hi @BillBudd,

There are a few tricks to eliminate this noise…
There are a few bits that generate noise, the cloudbit, the Arduino and the servos. The speaker is very very sensitive and catches a lot of noise when it is generated in the system…
First you could try to create some distance between your cloudbit & Arduino and the mp3 player or speaker, just add an extra wire bit between them. it might help. Just try a few places where to add the wire…

Another trick is adding a “noise filter” just before the speaker bit. Sometimes the noise enters the speaker bit via the VCC 5 Volt connection.
I experienced this when using the servo bits and made a filter with a 220 uF capacitor and a 100 Ohm resistor on the HDK bit. It really worked…
see this video where you also can see how the filter is built:

This is the original topic:



Thanks for your reply. I have tried putting distance between the speaker and the other bits to no effect. Would a filter bit do the same jib as your HDK built bit?

Kind regards,


Hi @BillBudd,
Just try the filter bit, but I suppose it will not minimize any noise coming through the VCC 5 Volt connection.
it filters the sounds coming from the SIG line only… :sweat_smile: