Hi. I have a bluetooth module that is controlled by Arduino and a D class amplifier this module connected to. Both, the amp and the module including Arduino share the same ground. There is a high pitched digital noise when BT module is connected to the amp. When not connected it is all quiet.
I had this problem before in another project, and solved it by using 2 separate power sources. But in current configuration there is only one battery source for everything. I will probably add another battery source to power digital part separately, but hoping I don’t have to do this and maybe there is a trick how to separate audio ground from digital ground. Does anyone know a good workaround? Thank you.
I had this problem before in another project, and solved it by using 2 separate power sources. But in current configuration there is only one battery source for everything. I will probably add another battery source to power digital part separately, but hoping I don’t have to do this and maybe there is a trick how to separate audio ground from digital ground. Does anyone know a good workaround? Thank you.
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I have found this thread Bluetooth module high frequency and buzzing noise and currently exploring option 2 from the post 2, dc to dc isolated converter. Option 4, using separate power supplies worked for me in the past, but not applicable here.
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Small Dc-Dc isolators are the usual solution. I think MornSun makes B0505 devices for 5v? 1w should be plenty for a BT device.
Yep, this is exactly what I used and it eliminated the problem. I used 1W but also ordered 2W and 1A for future projects.