We’ve Got It Down PAT: Appliance Electrical Safety Testing

May 4, 2017 by Jenny List 23 Comments

Everywhere we look in our everyday lives, from our bench to our bedroom, there are the ubiquitous electrical cords of mains-powered appliances. We don’t give our electrical devices a second thought, but in addition to their primary purpose they all perform the function of keeping us safe from the dangerous mains voltages delivered from our wall sockets.

Of course, we’ve all had appliances that have become damaged. How often have you seen a plug held together with electrical tape, or a cord with some of its outer sheath missing? It’s something that we shouldn’t do, but it’s likely many readers are guiltily shuffling a particular piece of equipment out of the way at the moment.

In most countries there are electrical regulations which impose some level of electrical safety on commercial premises. Under those regulations, all appliances must be regularly tested, and any appliances that fail the tests must be either repaired or taken out of service

In the United Kingdom,where this piece is being written, the law in question is the Electricity At Work Regulations 1989, which specifies the maintenance of electrical safety and that there should be evidence of regular maintenance of electrical appliances. It doesn’t specify how this should be done, but the way this is usually achieved is by a set of electrical tests whose official name: “In-service Inspection & Testing of Electrical Equipment”, isn’t very catchy. Thus “Portable Appliance Testing”, or PAT, is how the process is usually referred to. Join me after the break for an overview of the PAT system.

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Mission Control For Kerbal

May 4, 2017 by Al Williams 31 Comments

[Niko1499] had a plan. He’d built a cool hardware controller for the game Kerbal Space Program (KSP). He got a lot of positive reaction to it and decided to form a company to produce them. As many people have found out, though, that’s easier said than done, and the planned company fell short of its goals. However, [Niko1499] has taken his controller and documented a lot about its construction, including some of the process he used to get there.

If you haven’t run into it before, KSP is sort of half simulator, half game. You take command of an alien space program and develop it, plan and execute missions, and so on. The physics simulation is quite realistic, and the game has a large following.

When we first saw the photos, we thought it was an old Heathkit trainer, and–indeed–the case is from an old Heathkit. However, the panel is laser cut, and the software is Arduino-based. [Niko1499] covers a few different methods of letting the Arduino control the game by emulating a joystick, a keyboard, or by using some software to take serial data and use it to control the game.

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Reverse-Engineering The Peugeot 207’s CAN Bus

May 4, 2017 by Anool Mahidharia 53 Comments

Here’s a classic “one thing led to another” car hack. [Alexandre Blin] wanted a reversing camera for his old Peugeot 207 and went down a rabbit hole which led him to do some extreme CAN bus reverse-engineering with Arduino and iOS. Buying an expensive bezel, a cheap HDMI display, an Arduino, a CAN bus shield, an iPod touch with a ghetto serial interface cable that didn’t work out, a HM-10 BLE module, an iPad 4S, the camera itself, and about a year and a half of working on it intermittently, he finally emerged poorer by about 275€, but victorious in a job well done. A company retrofit would not only have cost him a lot more, but would have deprived him of everything that he learned along the way.

Adding the camera was the easiest part of the exercise when he found an after-market version specifically meant for his 207 model. The original non-graphical display had to make room for a new HDMI display and a fresh bezel, which cost him much more than the display. Besides displaying the camera image when reversing, the new display also needed to show all of the other entertainment system information. This couldn’t be obtained from the OBD-II port but the CAN bus looked promising, although he couldn’t find any details for his model initially. But with over 2.5 million of the 207’s on the road, it wasn’t long before [Alexandre] hit jackpot in a French University student project who used a 207 to study the CAN bus. The 207’s CAN bus system was sub-divided in to three separate buses and the “comfort” bus provided all the data he needed. To decode the CAN frames, he used an Arduino, a CAN bus shield and a python script to visualize the data, checking to see which frames changed when he performed certain functions — such as changing volume or putting the gear in reverse, for example.

The Arduino could not drive the HDMI display directly, so he needed additional hardware to complete his hack. While a Raspberry Pi would have been ideal, [Alexandre] is an iOS developer so he naturally gravitated towards the Apple ecosystem. He connected an old iPod to the Arduino via a serial connection from the Dock port on the iPod. But using the Apple HDMI adapter to connect to the display broke the serial connection, so he had to put his thinking cap back on. This time, he used a HM-10 BLE module connected to the Arduino, and replaced the older iPod Touch (which didn’t support BLE) with a more modern iPhone 4S. Once he had all the bits and pieces working, it wasn’t too long before he could wrap up this long drawn upgrade, but the final result looks as good as a factory original. Check out the video after the break.

It’s great to read about these kinds of hacks where the hacker digs in his feet and doesn’t give up until it’s done and dusted. And thanks to his detailed post, and all the code shared on his GitHub repository, it should be easy to replicate this the second time around, for those looking to upgrade their old 207. And if you’re looking for inspiration, check out this great Homemade Subaru Head Unit Upgrade.

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