Layout
The pinout from Happymodels site.

It’s so tiny, that it is almost impossible not to damage something by soldering unwanted parts together. But I really needed a good buzzer to find it back.
Disamble the Mobula.![]()
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Powered everything up and everything works without smoke. So I can continue to do the buzz mod.
Soldering
The first pad was “easy”.
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The second pad is so close to other components, it is almost not visible with the naked eye. So I added a loupe to my whislist 😁
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But some time and coffee’s later it is attached.![]()
Securing
Powering on the hotglue gun.
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Fixating the fragile wire connection to hold it in place and preventing short circuit.
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Done !
Extra protection
I put a piece of plastic between the boards because I’m scared now for shorting.
It’s a cheap and easy mode that gives me more trust.
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Everything put back together with a nice buzzer exhaust !
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That was it for now !