Bluetooth Module Wiring Diagram - NRF51822

I’m getting ready to install my own Bluetooth module per surfdado’s YouTube video, so I took the liberty of making a wiring diagram so that the setup is a little clearer.

surfdado’s video - OneWheel XR VESC Conversion - Step by Step Part 3 - YouTube
Bluetooth modules -
JST connector kit -


To be clear, the pulldown resistors are only for the foot sensors, I wanted them to disengage more quickly because I felt that the built-in 10k pulldowns were too slow. But in the meantime I have to admit that I’m not sure that this is really needed. I haven’t heard of anyone complain about sensor issues so maybe I just had a sticky sensor to begin with

Also, did you get your modules from “Hiletgo” to work? I’m about to return the latest batch I ordered from Amazon. None of them worked. Programming worked, but they never showed up in my apps…

I have not gotten any of my hiteligo NRF51822 to work, I even switched the tx and rx like you advised. I have 2 of them the first one I desoldred the pins (pain in the ass) the 2nd one I just used pin connectors, both dont work. Let me know If you find one that works. Also the pull down works. As part of my trouble shooting I unplugged them (still did not work) but quick stop is hard as it lurches forward (mini ghost) so I will keep the resistors.

Wait Surfdado, do I need to program them before installing? Using your firmware, I thought it was just wire plug and play?

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they’re generic bluetooth modules, they don’t know how to talk to a VESC - so they do need to be programmed. Just google VESC and NRF51822 and follow that video

Feel like an idiot now, I guess these are the things techie people assume non techie people already know. I guess I will need to buy a STLinkV2 and learn how to program this. I bought another 2 thinking I had a bad batch. I guess once I learn how to program them I can give them away.

Is this a good guide to follow? NRF51822 Flashing / Setup in Windows using a STLink V2 - How-Tos - DIY Electric Skateboard Forums

Thank you for the patience.

Can you tell me which one of these I should use for our Hiteligo modules. Cannot tell from the amazon description.

All I assumed is that you google it :wink:

And the first result should be a video of Vedder showing how to program that exact BLE module using just a VESC - no ST Link

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Did see vedders instruction but he mentions using an st link

“The upload script assumes that the NRF51822 is connected over SWD using an stlink v2 with the following connection:”

This is link GitHub - vedderb/nrf51_vesc: BLE-UART bridge for the VESC with packet handling and VESC Tool compatibility

Does he have another post on how to do it without an stlink?

Never mind found it (video link)

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Yeah, I haven’t had any issues with my sensor, so I was going to omit the pulldown resistors. But I included it in the diagram since I was referencing your work. Perhaps I’ll add a note that they are optional.

I haven’t actually had time to open up my controller and connect the module yet, so I’m not sure if the HiLetGo will work. Fingers crossed.

Fwiw I’ve now been trying for weeks to find another bluetooth module that I can get to work but I keep failing. The HiLetgo modules no longer work (I tried 4 or 5 of them) and the tiny Nordic modules have the same problem. No idea why, maybe counterfeit chips? Idk - and people in the Vesc discord also offered no clues so far

I now ordered an expensive one from AdaFruit ($15 including shipping), let’s see if that one works.

Could one not just use a preprogrammed BLE module for VESC? I sometimes put these into boards when the ESC doesn’t have onboard BT:

They’re not exactly cheap, but they wire in via the usual UART port pins of TX/RX/+/Gd

I think the FOCer’s UART pins are mixed in, so you’d have to re-pin the JST, but it’s still just the regular ones, and should just work.

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This may not work as I have the Hiletgo modules that aren’t working. Its my understanding that the module is programmed in a different config than how it is used. I have watched Vedder’s video and he is connected to IO,GRD,CLK & VCC, but these don’t look like options on the FOCer?

Also, Why are we connecting ADC1 and ADC2? The footpads should already be attached to the three pin?

Yeah it looks like the Flipsky that Mario linked might be the better option now.

I’m not sure why it’s connecting to ADC1 and ADC2. Perhaps @surfdado can can answer that though.

Would you mind naming the pins on the Bluetooth modules, my NRF51822 has 2 sets of 9 rows, so it’s not as simple as counting for me…

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I’m out of town until the end of the month, but I’ll see if I can get that for you when I’m home.

Did you get a chance? I gave it my best guess, but i guess it was wrong…

Edit: after closely examining the video i believe i connected it right, i possible just have a faulty unit like is discussed in the beginning of the thread

Sorry, I totally forgot about this! Hopefully this is still helpful:

FYI - I ended up using a Flipsky BT Module like @mariocontino linked above. If you buy one, make sure to get the V4, as it has the correct JST connector for the Little FOCer. This is the one I bought:

The linked module all hooked up and good to go? Ordering soon if so and if it makes the focer work well with iphone.