Metr Pro UNITY bluetooth module

Fellow master builders!

We are happy to announce Metr Pro UNITY edition. It has been in the works since the beginning of this year and is finally ready!

The most important feature is EASY INSTALL


  1. Lift up UNITY rubber case
  2. Remove factory BLE module
  3. Insert Metr Pro
  4. ???
  5. PROFIT!!!

Metr Pro UNITY has a newer nRF52840 chip from Nordic. Otherwise it is the same good and proven Metr Pro module. It works as you would expect, just in a different form factor:

  • :alien: Firmware Over-The-Air updates
  • :lock: BLE security with Elliptic Curve Cryptography and Man-in-the-Middle protection
  • :hammer: BAUD rate and RX/TX autodetection, plug and play
  • :shield: Metal shield and 3-LED status indication
  • :peace_symbol: Works with many apps (Metr, UNITY, Xmatic)

metrprounity PRICE: €50 (+19% VAT for EU)

We are getting feedback from our beta testers @mackann @StefanMe @janpom and so far only found one software issue that we want to fix before shipping the modules to everyone. This is purely software, the hardware is ready. We expect to ship the modules next week.


As someone who has serious issues with the stock Unity Bluetooth module freezing / crashing due to voltage spikes, the Metr module looks very appealing and I’m close to ordering one. You posted a closeup shot of the PCB in the other Metr Pro thread and I noticed you had two ceramic caps between GND and VCC. Is this enough to smooth out the voltage and keep the module from crashing/freezing? Have you taken this into consideration when designing this?

Bit hesitant to place the order, since not sure if the Unity stock Bluetooth module is just trash or if it is an issue with the Unity itself and if buying a Metr module would even fix it. Obviously having access to all the great Metr features is something I’m very much looking forward to. :slight_smile:

We have not experienced any crashes of the module so far. As you mentioned both caps very close to the nRF52840 module should help a lot smoothing out some spikes. We have to wait for some more results form our beta testers, but so far it is looking good. I am waiting for a FOCBOX UNITY myself for some month for more electrical analysis and scope the 3.3V for an example, but not sure if Enertion is holding their shipping dates now. They already delayed the announced date to ship them a few times.

I will keep you updated with results from our beta tester. I know @janpom experienced these crashes with the OEM UNITY BT module also and should have the new Metr Pro UNITY in his hands very soon. Post delayed the shipping of his beta module a bit.

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Ordered! I will report about stability asap (hopefully end of next week).

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@McErono Just out of curiosity, have you experienced forementioned bluetooth freezes with the Unity stock BT module?

Yes all the time but since firmware 23.44 it got a lot better.

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purchased. WOOT

I ordered two module( Metr Pro UNITY bluetooth module and Metr Pro bluetooth module) I sent additional shipping information by e-mail. Check please!!!

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It still has a password like your normal metr modules yeah? I got 2 because the unity lacks this security feature.

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@Martin Received your payment. Thanks. Also received your shipping information already via PayPal, but thanks for sending it via e-mail again so I can confirm you we have it right.

@nuttyjeff Yes, it still features BLE security with Elliptic Curve Cryptography and Man-in-the-Middle protection, so you have a 6 digit password like on standard Metr Pro modules.

Cool. Already placed my order. Thanks!


I’ve been eyeing up a Focbox unity but loved my metr pro, i can now upgrade woooo! Good work guys you produce the best module / app. Thank you


Interested in getting one of these for a cleaner look but I’ve already got a brand new never used Metr Pro bluetooth module. I upgraded my focboxs to a unity before I got around to installing it so if anyone in the EU is interested in a new Metr Pro bluetooth module, send me a pm.

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First Metr Pro UNITY modules are completely assembled and each of them tested, so first orders will be shipped tomorrow. You will receive the tracking number via PayPal when your package is send. Metr_Pro_UNITY_2

To install the module follow the video and steps Roman posted.

We recommend turning off the FOCBOX UNITY when you switch the OEM module for the new Metr Pro one. Make sure you plug the 2x3 pin header to the right spot of the internal connector where the old module was sitting before. Turn the UNITY on after confirming its plugged in correctly.

Each Metr Pro UNITY comes with its own pairing pin code like you can see in the following picture. Metr_Pro_UNITY_pincode Please note down your pairing code before closing your boards enclosure so you have it ready for first time connecting to the metr app. To connect to the module go to “Settings”, hit the scan button and tab on your Metr Pro module thats shown in the list. You are asked to put in the 6 digit code. Its only necessary to put in the code ones, so afterwards your phone will directly connect to the module when opening the app. Set up your wheel diameter, motor poles etc. under “Settings” -> “Motor” and your battery settings under “Settings” -> “Battery” and you are ready to go. Start records, see realtime data, use modes, change ESC settings and enjoy your ride.:slightly_smiling_face:


I was able to test the Metr Unity module today. I did have freezing issues with the stock Unity BT module and Xmatic. In Xmatic, the freezing still happens with the Metr module. However, the Metr module has been working flawlessly with the Metr app. I recorded a 17km test ride. There’s no indication of any connection dropouts in the log. Here it is:

The idle sections are where I know I have actually stopped for a short break. You can also tell that the FET temperature went down during the breaks. Clearly not a connection loss.


Quick follow up. All orders placed before 04 June 2019 are shipped now. You should receive the tracking number via PayPal. Use this website to track the package.


Ordered! I sent you an email with my shipping address. Paypal was not updated after my recent move. I look forward to tying it out!!!


Got your email with new shipping address and updated it.

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Thank you!

my module arrived yesterday, will test it over the weekend! :star_struck: