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Stereo Bluetooth Transmitter Transmitter Transmitter Circuit Help Answered

Hey All,

I am currently working on a LiPo Battery Adjustable Voltage Battery Pack, that has a headphone amp and bluetooth transmitter built in. I want the user to be able to use any compatible BT Headphones or BT Receiver Dongle. It is for use with metal detectors.  Every time I Google Bluetooth Transmitter Module, I find a bunch. Upon closer inspection, I find they are all receivers (i.e. speaker left out, speaker right out). There are bluetooth dongles that plug into a 3.5mm jack and transmit, but there is a lag in the transmission that I believe stems from the module not being hardwired into the system. A lag in receiving the BEEP means the object is harder to pinpoint, more digging, bigger holes, and frustrated folks. Can anyone recommend a good available BT Transmitter Module that I can hardwire into my system as a test to see if the lag goes away?

Any assistance y'all could give would be greatly appreciated!



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6 years ago

For my detector I used a wireless headphone set, was dirt cheap too as it was a display model.

The transmitter had the choice of RCA or headphone jack input.

Supply voltage was 6V and I used the power supply for the detector with a simple voltage regulator to power it.

The transmitter was quite good and only needed very little power.

I abandoned the use after I noticed the headphones only last for about 4 hours before they needed a recharge.

With only tiny rechargable cell inside I did not bother to modify it as I thought it would be too heavy.

This was several years ago and the technology made big jumps since.

Unless it is for a commercial build I would look into a headphone set first.

If you need to stick with BT be aware that there are different protocols for the audio trnasmission, you will need one that can at least handle most of them.

The Miccus Mini-jack TX is quite good and still in the lower price range.

The TaoTronics TT-BA01 or the Ezetek Mini Wireless Bluetooth Transmitter are available too.

If you need support for your mobile phone as well (would be great to keep the headphones on) check the functions of the Avantree Saturn mini.

All BT transmitters have a slight delay, the good ones aroun 30-40ms.

But unless they have around 150ms delay or more there should be no issues finding that nugget.

Downside with most is the possible running time and charging / battery options.

It pays off to select something small that runs on 5V to be able to just use a standard voltage regulator to power it.

Depends on how long you have to be able to use it non stop though....


Reply 6 years ago

Thanks. Power is no problem as everything is being run off of an 11,000mAh 7.4v Lipo Battery on a circuit I designed to fit the case (150mm x 100mm x 35mm). I am building the test mule to work with my modded Minelab SD2000 Gold Machine. I had planned to just run a 5v regulator and circuit on to an empty space on the PCB.

I looked at the TAOTronics, but didn't want to tear up a $30 BT Device to use the pcb. I was hoping someone here could guide me to a solder up (or solder in) module that would work. I think that BT ver 4.0 may have solved the latency issue, but can't be certain until I actually have it up and running.

Thanks Again - Mike