CAN-Bus ExpansionCard

As a side-project, I‘ve been working with NMEA200 (based on the CAN bus) to create some electronics for boats. I always used a separate breadboard for the CAN to USB „adapter“. I thought of building an ExpansionCard for it. How many of you would be interested in it?


I would definitely be interested. Would this be a bus analyzer/ be able to send packets?

While I’m not personally interested, I would like to point out that this could also be of interest to 3D printer enthusiasts. Many custom 3D printers use CAN bus.

Actually, I’m on my university rocketry team, and we’re using CAN Bus for out test stands, and having an interface like that would be really great. So if you do I would be interested

My use case is also for a university team, our solar car uses CANBus between boards.

Thanks guys. I thought of a simple transceiver with CAN_L and CAN_H. Which voltage do you guys want as an output? 12V? No voltage at all?

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Could the same card also speak RS485?

If anything, my team uses 5V. Should make it simple with USB.

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Current progress

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Hm. Could you please tell me, what’s the point in having an expansion card with PLS pins sticking out?

I mean, that would definitely prevent it from being inserted for a long time, since the pins would be bent/broken, like, 5 minutes later.

In that case it would be easier just to have a USB dongle.

Oh, i forgot to explain. I didn’t find a footprint for a screw terminal so i just used the pin header because it’s the same footprint. I’ll build the first prototype and will then see if it stays like this


Maybe it‘s better to have a normal pinsocket, because not everyone has a screw driver ready at all time.


Yeah if you can fit them standard 2.54mm female pin headers would probably be best. Looks really good so far!

Should be updated. Now it‘s on master branch. I‘ll start with the mechanical design soon.

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I’ve also been working on a CAN expansion card on-and-off for the last few months.
My design is inspired by the CANable 2.0, an open-source USB-to-CAN adapter.
It will support standard CAN (up to 1MBaud) and CANFD (Up to 5MBaud).

Here’s some renders of the expansion card (Without the top cover):


The biggest challenge was finding a suitable connector that fits and provides a good user experience. I ended up settling on a push-in spring connector style, which allows easy tool-free insertion of wires. The connector itself is removable, and doesn’t leave pins sticking out of the expansion card when removed.

The 4-pin connector has GND, CANH/L, and a 5V output pin.

I’ve already ordered a batch of prototype boards, and I should receive them in the next week or so to start testing them.

You can find my design files here: GitHub - JackToaster/framework-usb2can: USB to CAN device in a Framework laptop expansion card


CAN expansion card is in and assembled! I just need to print the case and test it.


Awesome to see! Any idea if you’re going to sell assembled cards?

Hey! Really cool design. How‘s the status?

For mine i‘m still relying on the classic jumper wire connector and the ESP32-C3 Mini 1U and I‘ll post a new picture of the current card in here as soon as I order my PCB.

If you are interested in selling an assembled version with some form of enclosure, I would be very interested.

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