Warning: this is a geek post pertaining to the CanSee dongle, not CanZE, nor the ELM style dongles.

In the CanSee design we’ve specified the SN65HVD23x chip to translate the micro-controller’s logic levels to the CANbus. The beauty of this series of chips is that it runs on 3.3 volt, thus requiring no level shifting and only one supply rail. As reported earlier we’ve seen many bad chips though. Lately I have been involved in a commercial project and we selected the same chip for the same reason. To make a very long (debugging) story short, faulty chips bit us again, and these were sourced through a reputable PCB manufacturer. I also received a few chips from a friend and again, one was bad. Either there is a huge manufacturing problem, or there is a massive batch of fake chips on the market, or these chips are extremely prone to damage.

This problem has been haunting us for well over a year now and after wasting many, many hours again sifting through chips, re-soldering, messing with the firmware, and countless other botches, the camel’s back has now definitely broken. I am changing the public design to set the DC-DC converter’s voltage to 5V, use that to supply the development board AND the alternative transceiver chip (an NXP TJA1050). I’ll also add two resistors to level-shift the signal from the transceiver to the ESP32.

While working on the ZE50, we found a silly bug in the CanSee firmware. If…

  • you have a ZE50
  • you build a CanSee dongle
  • you want to be on the bleeding edge on the CanZE beta’s

… please update the firmware as soon as possible. You can find it here.

Göran Nybom reported on the issue tracker that the Vgate iCar 3 ELM327, which at least seems not to be some no-brand-with-always-changing-guts dongle, works fine. Price seems fair (20-ish), and it’s smaller than the KONNWEI which people might like.

This is no endorsement, we don’t have one, but if you do, please comment with your results, so we can update the hardware page. Or send it to me 😉

Edit: unfortunately, the one I received did not support the ATAL command and contained a main controller with a scraped off top marking. So unfortunately, I cannot honestly recommend buying Vgate, at least not from Aliexpress or Ebay. it seems that these are carbon-copied too. Well, the shell at least.


Before you read on: this post in not an endorsement whatsoever. We stick 100% to our advice to either build a CanSee dongle if you want fast&furious, or buy a KONNWEI 902, as that is about the only dongle that is a fairly stable build for fairly cheap.

Having said that, as a sort of fun/silly experiment stemming from the “Use ISOTP fields” mode I wrote about earlier, I decided to order the absolute cheapest dongle I could get, and ended up with a usual “blue transparent case” model for under 2 Euros.

Guess what, it has a decent PIC processor, external EEPROM, Bluetooth 4.0 chip, and an Atmel (Microchip) CANbus transceiver. This is not some hacked together crappy thing with half baked software in the spare capacity of some Bluetooth controller. And here comes the unbelievable part. After some tweaking, I got it running with CanZE. I literally had to change two lines of code in the development branch. Which I will have to cross check with my KONNWEI dongle of course. I was honestly flabbergasted.

Although the last picture of Raplh’s Zoe Plugin has a make-like flair, he didn’t stop there and even installed some led indicators using a NeoPixel strip.

a perfectly fitting cover
a look above the cover
the NeoPixel’s are shining through the cover
easy to plug out
Start it up 😉

Thanks to Ralph for sending me pictures of his Zoe plugin, which is basically a CanSee dongle that exactly fit’s into the car. But take a look at the pictures yourself.

the bottom layer
the solder side
ESP32 installed
gluing the ODB connector
all connections in place
the installed plugin

The second print (blue) is finally usable, but I refined it to make it fit more neatly. The third print (orange) is the last one I did today and the components of my previous prototype fit perfectly.

The print may not look perfect, but hey, is quite a step above the “duck tape version”, isn’t it?