We strongly advise you to only use CanZE with dongles described below. 99% of the dongles on the well known auction sites are ELM327 clones and are build up from stolen and corrupt firmware. Using such a dongle may not work at best and put you and your car to unknown and unpredictable risks at worst

ELM327 dongles (KONNWEI 902)

We strongly advise you to only use CanZE with dongles described below. 99% of the dongles on the well known auction sites are ELM327 clones and are build up from stolen and corrupt firmware. Using such a dongle may put you and your car to unknown and unpredictable risks.

ELM327 (clones) are cheap easy devices. Note however that the cheap no-brand ones from China can be useless for CanZe, as they lack certain essential commands. They often do not work, even if they work in your ICE car. More details here.


We know CanZE works with the Konnwei KW902. If you order on ebay.com.au you find the ones shipped from mainland China and Hong Kong. These are usually about half the price if you take shipping into consideration, compared to the ones shipped from Europe, but you will have to wait 3-6 weeks for it to arrive. The exterior of this device with the four screws and the LED’s and an off button on the top is very distinctive and easy to recognize. They come in different colors, but that is not relevant.

The Maxiscan KW902 and the OBDII 2 KW902 Scan Auto Scanner look the same, are probably identical inside and also work.

Note that they are sold with Bluetooth or Wifi connectivity. The current Android application only supports Bluetooth, the iOS version only supports WiFi.

There is a dongle test app available for iOS here.

CanSee dongles

For real power users we developed an ESP32 based super fast CanSee dongle, tailored for use with CanZE. The project has it’s own page here.

It will set you back under EUR 20 in parts. Note that is an electronics build project. You need to build these devices yourself, and that includes soldering, hooking up a SAE J1962 connector, a transceiver, power converter, and mount it all in a proper case. We will absolutely not provide any help with that. But do expect several full screen updates per second, if your android device is up to snuff.

What should you choose?

The easiest choice are the KONNWEI 902 dongles. They are insanely cheap (EUR 13 delivered and all if you are patient) and work out of the box. The downside is that they are slow. Especially for free frames, they need to be set up, then set to listen mode, then wait until that frame shows on the bus, then stopped. To check relatively static values, such as battery health, temperatures, charger performance, voltages, they are your choice. We have done a lot of optimizations to get as much as possible out of these devices. You can now expect a full screen update in the App about once per  second. Also there is an experimental feature called “Use ISOTP fields” that will avoid free frames all together.

If you want near real time performance of fast changing fields such as uncorrected speed, pedal positions, power and torque levels, you need the CanSee dongle. We let it monitor all free frames and store them in it’s generous memory, ready to be picked up by the app at any time. Downside is you need to build this device yourself.

24 comments on “Hardware
  1. Umbi says:

    Hi, great work.
    I’d like to build an Arduno version, but maybe I’m simply blind: is there any info about how to connect the CAN transceiver and the Bluetooth Dongle to the Arduino.
    Sure, it’s in the source…but I’m blind AND lazy. 🙂


  2. Jeroen Meijer says:

    Just a quick “teaser”: you need no more than the hardware stated above and a SAE J1962 connector. The wiring is dead simple. Ground and 12V from the connector to the Due, the Canbus pins to the transceiver, and 4 wires between the transceiver and the Due. Also 4 wires to the HC-05. And that’s it from the hardware side. The Due board has a neat efficient power supply so no more components needed. The teensy is slightly cheaper, slightly (irrelevant for this project) less powerful, MUCH smaller, but as far as I know it needs an extra power supply board, so it might not be worth it.

  3. Hi ! Great job !
    As far as you know, is it possible to use it with the Renault Twizy ?

  4. Dom78 says:

    Really cool project. Thanks!

    I’ve got a Maxiscan KW902 and tried it with my Samsung Galaxy S5. It seams not to working fine. I can get some informations like the SOC or the Battery Heatmap but it doesn’t show me the weel pressure. On this and other sites it shows very fast some error or info messages. I’ve tested it at a R210 and Q240 with the same results. Any one a idea what goes wrong here? Thanks for any ideas.

  5. Dom78 says:

    Yes. I was in the Renault Garage today and they checked it. The sensors are paired. I have brand new VDO OEM Sensors. I made some screenhots. Can I upload or mail them to you? I still don’t get any pressure information.

  6. Dom78 says:

    Hmmm. Is it possible to send you some screenhots or a log file. Maybe you can help me with this? This would be so great!

  7. Dom78 says:

    Done. Hope it helps. Thanks…

  8. ZoeDoktor says:

    I just tested today the second Konnwei I ordered, this time a “Green” version. Same results.
    Adapter works, connects with Android and even Windows via Bluetooth fine.
    But .. same results.
    Most specific Error message is : “Cannot connect to the ECU of the car”, according torque software.
    No data and negative ELM test in CanZE.

    However at the same time my Icarsoft i907 works fine, reads a load of data out of my ZOE Can bus.
    What is going on? … Spent around 7 hours trying all protocolls in the Torque software.
    Same result as with my already sent-back first Konnwei 902.

    Any idea?
    KR, Franz

  9. Eduard Väth says:

    Just for information:
    My new Vgate OBDII icar Pro BLE 4.0 dongle works fine with CAN-ZE!
    Not so a Konnwei KW902 ELM327 Bluetooth OBD2 PS which I sent return.

  10. ChamFan says:

    Just got a Zoe last week and we’re loving it!
    For info I can pass on that I just got this £9.99 dongle to use with iOS from UK Amazon – NEXPEAK NX103 (https://amzn.to/31r2i03).
    It’s v1.5, my iPhone 7 found and connected to it easily over non-password WiFi, and the CanZE also connected to it automatically.
    All the interfaces look as expected and I’m glad to see SOH at 98% for our 2015 22,000mile R240 model.
    Thanks for the good work on CanZE. I’ll look forward to using it some more. : )

  11. jra says:

    I just bought the Formulaone from Amazon.fr, and it worked correctly. Link: https://www.amazon.fr/gp/product/B07GRD5W65

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