Router controlling choo-choos over the CAN bus


This setup is used to control a model railroad. Well, not entirely this setup. [Gerhard Bertelsmann] already has a proper railroad controller, and it just happens to offer CAN bus communications. He’s using OpenWRT and a cheap router to connect the bus to the network.

Originally he wanted to use a Raspberry Pi board for the project, but the incredible backorder  situation with that hardware led him to grab an old router. After loading OpenWRT he started working out how to connect a couple of ICs (MCP2515 and MCP2551) that will take care of the CAN bus communications. The hardware connections end up being pretty simple, with five data lines (and their pull-up resistors) connecting to the router’s serial header. From there it was a matter of mapping the device in software so that the hardware can be controlled over the network.

We like this example since CAN is used is a lot of other applications.

Tuna can and some other trash turned into a Stirling engine

Next time you’re making yourself a tunafish sandwich, try to figure out how to build a Stirling engine from the leftovers (translated). If you can pull it off as well as [Killerlot] did we’d say you’ve earned your hacker badge.

The can used in this project was actually sardines in tomato sauce, but the former contents are moot. The can serves as a steam chamber for the sterling engine. A cam rod, piston, and valve are all fashioned from paperclips, along with the support structure that holds them in place. Inside the can is a damp sponge. When an alcohol lamp is placed beneath the can it heats the water air inside, which creates pressure on the piston, pushing it up until the cam opens the valve, relieving pressure just in time for the cycle to start over again. Momentum is a necessary part of the mechanism and that’s where the CD fly-wheel comes in. See it chugging along in the clip after the break.

Update: Corrected spelling thanks to [Chris Muncy] and removed references to water/steam thanks to this comment from [Khordas].

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Robot vacuum makes cleaning into a game

This is not a Roomba hack, but a ground-up vacuum cleaner robot build. It’s the result of a class project from six students at the Royal Institute of Technology in Sweden. There’s a slew of information available in their paper, but fair warning that it’s an 8.6 MB PDF file that we couldn’t get Google to translate. We were able to skim the PDF and cut and paste to translate the interesting bits we found.

Unlike a Roomba, which just uses a little sweeper to pick up debris, this robot actually includes a vacuum. The image above shows that the cylindrical body is wrapped in an LED matrix, with an ultrasonic sensor on the front for obstacle avoidance. The robot uses a CAN bus to control the various modules inside. We don’t think there’s any autonomous function, but that’s made up for by the remote control. It communicates via a ZigBee module, and includes a d-pad, touch screen, and accelerometer.We’re a little bit hazy on how the games are played, but there are at least two interactive version: one called ball, and another modeled after the classic game of missile command.

You can check out the source code for the project in their repository, or join us after the break for two demo videos.

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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...]

Modern car data systems lack security

Tomorrow a team of researchers will present their paper on Experimental Security Analysis of a Modern Automobile (PDF) at the IEEE Symposium on Security & Privacy. Much like the racing simulators we’ve seen they’re exploiting the ODB-II port to get at the vehicle’s Controller-area network, or CAN-bus. We’re not surprised at all that they can display custom text on the dashboard display or read sensor data from the car. What does surprise us is their exposé on how truly unsecured the system is. It seems that access to any device on the CAN-bus gives them unobstructed control of the car’s systems. Any device can send commands to any other device. They’ve even found a way to write malicious code to the car’s computer which can be programmed to erase itself in the event of a crash.

Much like RFID the security risks here are basically nill for the vast majority of consumers. We just find it a bit surprising that there’s apparently been little thought put into fortifying the communications between the safety systems such as the brakes on the vehicle. For instance, team experimented with sending random packets over the CAN-bus and stumbled across a way to lock the brake on just one wheel. To us it’s conceivable that a malfunctioning device on the network could start sending out damaged packets and cause a dangerous malfunction like this one.

The 14-page PDF linked above is a page-turner, check it out on your hacked ereader during lunch.

Beer can pinhole camera

When [Justin Quinnell] sent in his beer can pinhole camera, we were just floored. The parts are easy to obtain, and the process for building and ‘shooting’ with the camera are near effortless.

The really impressive part of this hack is letting your camera sit for 6 months facing the sun. Yes, you read that correct, a 6 month exposure. Check out after the break for one of his astonishing shots, and trust us, its well worth the click. [Read more...]

Now you can record mermaids singing

Buy stock in hot glue, this project corners the market on the stuff. [Leafcutter John] uses the hot goop as his water-proofer of choice when building an underwater microphone (also known as a hydrophone). By installing a couple of piezo elements on one lid of a tin can he is able to record some amazingly clear audio. This is aided by a pre-amp inside the metal enclosure. By cleaning off the clear coating from the inside of these steel can parts, he was able to solder the seams to keep the water out.  In the end, coins are added for ballast and any remaining space is completely filled with hot glue.

He’s got a handful of example recordings on his project page. Here’s an what a running faucet sounds like from under water:


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