Bluetooth module with unusual pinout

[whiz115]

Hi

do you know any bluetooth module using the pinout in the photo?
none of the HM series and JDY i've seen, is compatible.

thank you.

 

[Pommie]

A bit more info would be useful. Where did the photo come from? That looks like the footprint for an ESP module.

Mike.

 

[whiz115]

A bit more info would be useful. Where did the photo come from? That looks like the footprint for an ESP module.

Mike.

hi

thank you for the reply, it's not a footprint for ESP module, it's for bluetooth which is missing and
i'm trying to find a suitable module, it allows communication with a microcontroller.

i could post another photo found online showing a bluetooth module soldered, but there are no
visible details such as part number.

 

[Pommie]

You didn't answer the question, where did the photo come from?

Mike.

 

[whiz115]

You didn't answer the question, where did the photo come from?

Mike.

it's the microcontroller board from an e-scooter, the bluetooth is missing on this version and you
cannot retrieve details such as mileage data or lock it and unlock it, etc.

the cost of changing the board with a version that has bluetooth on it, it's much
higher than the cost of the bluetooth module.

 

[rjenkinsgb]

Possibly a Microchip RN4020? Those have two ground connections at each end.

 

[whiz115]

Possibly a Microchip RN4020? Those have two ground connections at each end.

thanks for your response, but only the ground pin seems it kinda matches.. but the above
footprint if you noticed has a left side of 7 pins and a right side of 6 pins and not 8,
there's also pin pitch difference for the first pin in the left side.

 

[rjenkinsgb]

Without seeing the overall PCB so tracks can be traced, it's purely guesswork..

 

[whiz115]

Without seeing the overall PCB so tracks can be traced, it's purely guesswork..

could it be for a custom built bluetooth module, so that's why i can't find a suitable
commercial module to fit?

 

[rjenkinsgb]

Without seeing the overall PCB so tracks can be traced, it's purely guesswork..

That's still the case.

 

[whiz115]

Without seeing the overall PCB so tracks can be traced, it's purely guesswork..

There's no closer photo of both sides so you can locate any tracks and the board is now
mounted back to its place.

i can remove few times the pcb before i need new adhesive for a plastic cover which
protects the pcb (it's similar adhesive used on a mobile phone's back cover).

but i wonder...if knowing the VCC/ground pins and footprint can't remind you any
known bluetooth module, then how it can be more helpful spending time tracing
every other pin?

that's a job i need to do.. later on if i find a module which seems compatible.



Pommie you any clue?

 

[ChrisP58]

Even if you found the right bluetooth module, it may not work.

If the firmware in the onboard processor isn't set to talk to the module, then no information will be available.

 

[Pommie]

If the firmware in the onboard processor isn't set to talk to the module, then no information will be available.

It's probably simpler (and cheaper) to have the same firmware on all the model. A quick check at the beginning can easily ascertain if the module is there or not.
However, there might be other hardware differences and without comparing the two (different) boards, no way to tell.

Mike.

 

[whiz115]

Even if you found the right bluetooth module, it may not work.

If the firmware in the onboard processor isn't set to talk to the module, then no information will be available.

It's probably simpler (and cheaper) to have the same firmware on all the model. A quick check at the beginning can easily ascertain if the module is there or not.
However, there might be other hardware differences and without comparing the two (different) boards, no way to tell.

Mike.

yes that's exactly my initial thought.. it's a cut down version for lower cost..
the board having the bluetooth are exactly the same, so i guess they didn't
spent time to make different firmware for each version.

so since we can't find a suitable module i assume it's custom built bluetooth.

thanks guys.

 

[Nigel Goodwin]

yes that's exactly my initial thought.. it's a cut down version for lower cost..
the board having the bluetooth are exactly the same, so i guess they didn't
spent time to make different firmware for each version.

so since we can't find a suitable module i assume it's custom built bluetooth.

thanks guys.

It's unlikely that a large scale manufacturer would use off the shelf Chinese modules, they would simply buy the IC's and build their own - one reason would be that it's to prevent people doing what you're wanting to! , another would be for cost - it's cheaper for them to make their own than buy the modules. Bear in mind they can probably buy the parts for the module for the same price at the module manufacturers do, making their own means they get the profit that would have gone to the module manufacturers.

It's very likely that the module is just a simple copy of the chips datasheet, and if you could find a cheap module that uses the same chip, it could be worth giving it a try (although you'll probably have to make your own connections).

 

[whiz115]

It's very likely that the module is just a simple copy of the chips datasheet, and if you could find a cheap module that uses the same chip, it could be worth giving it a try (although you'll probably have to make your own connections).

i'm certain the BT chip used on their custom module it's one of the known chips...
and i've already considered buying the closest match i can get (in appearance) and then
try to fit it on the board.

without bluetooth you can't have so many important futures such as locking and unlocking it
for minimal sefety in case somebody tries to steal it if you take your eyes away for a minute!

 

[whiz115]

if i show you some progress, then somebody might try to boost my effort??..

so here's the full pinout in the photo i guess there's no such commercial
bluetooth module with that pinout right?

P.S at first i thought it was I2C communication because the microcontroller's
manual had SDA/SCL designations for the RX and TX pins.

 

[ChrisP58]

SDA and SCL are I2C labels. TXD and RXD are UART labels. You might look to see if there are pullup resistors on those two lines. They would be needed for I2C. Although that wouldn't be an absolute indicator, they could be populated on the BT module.

One thing you might try is looking for any activity on those pins with a scope or logic analyzer.

Are there any other parts connected to those pins?

 

[whiz115]

SDA and SCL are I2C labels. TXD and RXD are UART labels. You might look to see if there are pullup resistors on those two lines. They would be needed for I2C. Although that wouldn't be an absolute indicator, they could be populated on the BT module.

One thing you might try is looking for any activity on those pins with a scope or logic analyzer.

Are there any other parts connected to those pins?

yes there are resistors in series with these pins... (220ohm and 100ohm for the LED pin).
i don't have scope or logic analyzer right now

 

[rjenkinsgb]

i guess there's no such commercial
bluetooth module with that pinout right?

There are literally hundreds, if not thousands, of different mass-produced Bluetooth modules.
Digikey alone list over 700 lines.

Many that are sold as pinned modules with supposedly the same type number (like HC-05, HC-06 etc.) have totally different surface mount sub-modules.

I bought about ten different types last year, tying to get some specific surface mount modules.
They were all advertised as the real thing and with photos of the genuine Wavesen sub-module - and they were all different fakes with different pinouts to the real one.