Cheap CAN/USB interface

BonyCook · 03-16-2008, 12:12 PM

I put together a breadboard with a cheap-ish CAN interface so that I can eventually plug my Mac into a test car, and I am in the process of writing some software for it. Anybody else interested in this kind of thing?

Jirka Jirout · 03-16-2008, 04:56 PM

Is this a true USB/CAN interface, or just OBDII adapter? If it is a true USB/CAN, then I might be interested quie a bit (depending on price and other conditions of course). What chip are you using for the USB interface? FTDI? How does the device looks like to the computer - HID, Serial device or something else completely?

zapro · 03-16-2008, 06:20 PM

Sounds interesting.

What IC's are you using ?

Please come up with some more information, it's what i'm missing for my MacCar installation.

// Per.

BonyCook · 03-17-2008, 02:35 AM

It is a real CAN interface. It uses an FT2232 for the USB interface, an SJA1000 CAN controller, and a transceiver chip. As you can see, it's not really complex, and the part cost is managable, too, the most expensive part in this setup being the DLP2232M dev board for the FTDI chip. There is no MCU involved, so the device depends entirely on the host computer, and I'll have to test if this approach is fast enough for high-speed CAN, but it should be.

Unfortunately I haven't been able to test this, yet, as I fried the transceiver IC, and since it's SOIC, I'll have to do some soldering to fit another one to the breadboard.

As for the drivers, using the CAN controller through a serial interface is a bit complex (as you have to control the SJA1000 through the FT2232, so there's 2 ICs to manage), so there will be a higher level library to do stuff, such as a WriteCANMessage() or ReadBuffer() function, etc.

ptk · 03-17-2008, 03:35 AM

i will be interested too! only thing is, i am on windows.

zapro · 03-17-2008, 05:45 PM

I have the capabilities to lay out PCB for the parts, fabrication of PCB etc., and could be persuaded to give a hand with development if needed.

Give me a PM if interested, i will need the schematics to make the PCB.

I am not a programmer, just a hardware-guy, so the programming is off my head.

// Per.

Chizh · 03-19-2008, 12:23 PM

Is this is right for land rover discovery 3 (2006)?

TTeuer · 03-21-2008, 11:03 PM

Woot for VAG-Com

zapro · 04-01-2008, 07:24 AM

I have built this device, and despite i have not got my new car yet (will be ready in a few days) it seems to work.

It's a similar construction, and it works perfect. You can see the Documentation for it, it uses an Virtual serial port over USB to communicate - should be pretty easy to program an application for it!

http://www.mictronics.de/?page=can_bus

My friend Henri built the interface, and done some changes, my interface is 100% the same as his, you can have a look here: http://www.skippari.net/projects/can-usb-interface/

Regards, Per.

galvitron · 04-01-2008, 06:15 PM

^^ Looks great! Any plans to sell these things?

zapro · 04-11-2008, 09:43 AM

Quote: Originally Posted by galvitron

^^ Looks great! Any plans to sell these things?

Well, no.

I think that Henri made 2-3 PCB's and i got one of them. I could make PCB's but it's a lot of work to do double sided PCB's by hand.

I'm unsure if the author (Mictronics) is OK with selling devices that use his proprietary code, you will have to ask him if it's OK to make this device and sell it.

Anyway, i have got my car now - It's an Mitsubishi Colt 1,3 '08 with CAN and the board works as it should. The car uses 500 MPBS bitspeed and theres a ****load of data when the ignition is turned on!

// Per.