Bluetooth speaker module (spk md blk-b)

[Lee_horner93]

Hi folks! I've been working on a a small Bluetooth project, creating a set of Bluetooth headphones, using the Bluetooth speaker module spk md blk-b that I purchased a few weeks ago from  somewhere in China. Unfortunately I can't find any proper wiring diagrams or schematics for this specific chip, I will attach a few pictures. The problem is I can't seem to power the chip up no mater what I try, and I have tried with two separate modules.
I have seen diagrams of similar modules that feature a multi function button (mfb) that requires a long press (3sec) from the power supply to power it up. If anybody has any information on the chip that I have or know off any other methods to try and power it up that would be great!

[Buriedcode]

Depending on which diagram you provided is your module, you need to pull the "Vreg" or "MFB" line high - to Vbatt via a 10k resistor will do.  MFB = multifunction button and is usually the "pairing/power on/off" button on bluetooth audio devices.  It is also sometimes referred to as Vreg, even though it is an input.  It is essentially what powers up/down the internal 1.8V regulator which powered the chip.

I assume you mean this module: https://www.elecfreaks.com/wiki/index.php?title=BLK-MD-SPK-B

[Lee_horner93]

Thanks for the response! Apologies the top image is the board I have, with the charging pins across the bottom. I will try this later. You wouldnt happen to know if the 1.8v circuit earths on the same pins as the 3.3v circuit?


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[Buriedcode]

Yes, all the grounds should be connected.  The 1.8V comes frm the module (on-board voltage regulator) but the 3.3V is supplied externally.  It is designed to run from a lithium polymer battery so 3.3-4.2V on Vbatt.  So for your module, Vbat is 3.3V in, and "Vreg" should be connected to Vbat by a 10k resistor.

[Lee_horner93]

Just tried tried pulling the Vreg pin high and it works perfectly! Thanks very much!

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[suraj]

need a help to design a low cost bluetooth speaker. It will be very helpful if you provide me a refrence circuit daigram