This is a placeholder topic for “Bluetooth 5.0 Audio Receiver Board” comments.
How does this board work with stereo sound?
It is my understanding that to have stereo sound, both the Left and Right RCA must have a seperate ground, this board only has one, am i correct or is there something I am missing?
Thank you
welcome to the core forum
without going into amplifier design…and types generally …
it uses the same ground point for each channel in this and most cases…its just duplicated …
so you would connect your leads to this board by joining both grounds to its ground pad…or just use a 3.5 mm phono stereo to rca lead and use the onboard audio jack
in the case of bridged amplifiers…etc and alike.they have two separate grounds or earths if you will…
depending of the amplifier class design
https://www.dfrobot.com/product-2085.html
website boasts 2x5 watt out on sales page no wiki available…
on my list to add to my rpi-4 8 gig
Hi Nathan,
You typically only need separate grounds on the output of the amplifier (particularly when you have an amplifier per channel). For line level outputs like on this board, you can get away with a common ground.
Hi! I am thinking of buying this, but am wondering if it supports charging a rechargeable battery through the micro usb. thanks!
Hi Daniel,
This one doesn’t have any charging circuitry on board, it just takes power in. You’d be best to pair it with a LiPo which has built in protective circuity, and a Lipo charger like this:
Hey. I was thinking of getting this to make a bluetooth speaker, and I was wondering, Can I attach LED’s to the Wired Speaker Output (the Left, Ground, and Right pads), and if so, what ones should I use?
Hi Kaelan,
There is an LED indicator already on the module, what are you hoping to achieve by connecting LEDs to the audio output?
The audio output is expecting an inductive load, usually around 4 Ohms, connecting a diode there might produce some strange results.
I’m thinking of adding LED’s that flash with audio, but seeing your response, I’m assuming that’s not possible.
Ahh, you probably want something that does a fast fourier transform. I’m sure I’ve seen a dedicated chip in the past that does exactly that and makes it really easy to implement but I can’t seem to find the one I’m looking for atm.
But this is the kind of thing I’m thinking of:
Hey Keelan and Oliver,
An MSGEQ7 is chip that will be able to achieve this. It is much more computationally intense to compute in software vs the chip, the math is quite interesting as well, especially trying to compute it in real time.
Can the Bluetooth name be changed? I can’t quite read the chipset to look for the data sheet…
Hi Beau,
Welcome to the forum!!
While you will be able to change the name you have to reprogram the chip presumably using the 4 pads on the back, I found a trail somewhere online and once I find some more info I’ll get back to you 
EDIT: it looks like theyre on holidays at the moment so it might be a while… No worries though, if you zoom in on your phone with the flashlight on you might be able to get the letters and numbers on the chip
Liam
Hi Liam, I soldered the links on the back, and now it shows up as a USB device.
[ 6518.596634] input: ZhuHai JieLi Technology JieLi BR21 as /devices/pci0000:00/0000:00:14.0/usb1/1-5/1-5:1.4/0003:E5B7:0811.0008/input/input29
[ 6518.655055] hid-generic 0003:E5B7:0811.0008: input,hidraw6: USB HID v2.01 Device [ZhuHai JieLi Technology JieLi BR21] on usb-0000:00:14.0-5/input4
The trick will be to see what we need to do with this, or what proprietary software is required 
It was a bit of a tight fit to get one of these inside a cassette but I like the result. Great way to add bluetooth to an old stereo.
-John
@John74609 that’s awesome! Fitting it in is an impressive feat!
It is a bit too tight to fit properly. Quite a bulge in the case, but good enough for me. 
Hi. I have a couple of these boards and they work very well, but the range is short in comparison to other Bluetooth devices I have. Is there any easy way of extended the range with some kind of external aerial? Thanks, John
How many devices can these modules be paired with?
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