ODB-II hacking using an Android tablet

odb-II-hacking-eagle-grand-cherokee

What a strange message to read on the digital dashboard display of your car. This is proof that [Kristoffer Smith] was able to control the ODB-II bus on his Eagle Grand Cherokee.

He’s not just doing this for the heck of it. It stems from his goal of adding an Android tablet on the dashboard which has been a popular hack as of late. This left [Kristoffer] with steering wheel controls that did nothing. They originally operated the radio, so he set out to make them control the tablet.

He had seen an Arduino used to control the CAN bus, but decided to go a different route. He grabbed a USB CAN bus interface for around $25. The first order of business was to use it with his computer to sniff the data available. From there he was able to decode the traffic and figure out the commands he needed to monitor. The last piece of the puzzle was to write his own Android code to watch for and react to the steering wheel buttons. You can check out the code at his repository and see the demo after the break.

[Read more...]

CAN sniffing for steering wheel button presses

You can make those buttons on your steering wheel much more functional if you have a way of monitoring them. Don’t even think of cracking open the factory finish to get to the solder points, just tap into the CAN bus and monitor the data traffic.

The small board seen above is the result of a project [Peter Shabino] calls the CAN sniffer. The connector on the left will plug into the Control Area Network system on your car, giving the chips on board something to do. There’s an MCP2551 CAN transceiver (hidden under that linear regulator) and an SPI controlled MCP2515 CAN controller which take care of the particulars of the CAN protocol. The big chip in the middle is a PIC 16F876, responsible for making sense out of the data. From there a MAX232 chip is used to provide a serial interface to connect the device to a computer.

This really isn’t tied down to one particular function. Once you have access to the bus for a microcontroller you’ll only be limited by your firmware writing skills. [Peter] has posted an archive with all of the open source files, as well as an illustrated step-by-step board assembly. We’ve embedded the schematic from that archive after the break. [Read more...]

Hackaday links: January 2, 2011

DIY driving controller

It looks like this steering wheel, shifter, and foot pedal were all made from string and garbage. That being said, you can see it works quite well. The setup just pushed keys on the keyboard,  which reminds us of the junky plastic add-ons for the Wii remote. [Thanks Toumal]

Taping PCI express

[Pseudolobster's] company was putting together point-of-sale machines for a retailer. They had surplus computers which really brought the price down but ran into a snag when adding the second monitor. The boxes wouldn’t play nicely with PCIe 16x. His solution was to scotch tape pins 19-82 on the cards, effectively turning them into PCIe 1x… and it worked! No link here but we wanted to share the trick anyway.

USB character display

[Simon Inns] shows how to add a character display to a PC case. We’ve seen him work with these PIC 18F2550 controllers several times before but we like how nicely this piggy-backs the display board seen in green.

Integrated steering wheel radio controls

van-pioneer (Custom)

[Graham] bought a new stereo for his Peugeot 406. Unfortunately, the built in radio controls in his steering wheel didn’t interface directly with the head unit, but rather with the vehicle itself. His solution was to build a device to decode the button presses and send them to the head unit in the appropriate fashion. All source code and schematics are available on his site. He states that this should work on any PSA/Renault vehicle with a 125Kb VAN bus. We’re curious how similar some of the American systems are. We have seen something similar where someone wanted to control their Zune from the steering wheel.