Hand Gestures Drive Car

There are a number of ways to control an automobile without using the pedals, and sometimes even without using the steering wheel. Most commonly these alternative control mechanisms are installed in vehicles whose owners are disabled in some way, but [Anurag] has taken this idea of alternative control one step further. He has built a car that can be driven by hand gestures alone.

On a remote controlled car, a Raspberry Pi 2 was installed that handles processing and communication. A wireless network is created on the Pi, and a laptop connects to the Pi over the network. The web camera on the laptop regularly captures frames at 15 fps to check for the driver’s hand gestures. The image is converted to gray scale, thresholded, contours are obtained, and the centroid and farthest points are obtained.

After some calculations are done, a movement decision is taken. The decision is passed to the Pi, which in turn, passed that to the internal chip of the car. All of the code is available on the project’s github page. [Anurag] hopes that this can be scaled up to full sized cars in the future. We’ve seen gesture-based remote controls before that rely on Sonar sensors, so it’s interesting to see one that relies strictly on image processing.

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Car Idle Alarm Helps You Stop Wasting Gas While Tweeting

[TVMiller] has a bone to pick with you if you let your car idle while you chat or text on your phone. He doesn’t like it, and he wants to break you of this wasteful habit – thus the idle-deterrence system he built that he seems to want on every car dashboard.

In the video below, the target of his efforts is clear – those who start the car then spend time updating Twitter or Instagram. His alarm is just an Arduino Nano that starts a timer when the car is started. Color-coded LEDs mark the time, and when the light goes red, an annoying beep starts to remind you to get on with the business of driving. The device also includes an accelerometer that resets the timer when the vehicle is in motion; the two-minute timeout should keep even the longest stop light from triggering the alarm.

[TVMiller] plans an amped-up version of the device built around an MKR1000 that will dump idle to moving ratios and other stats to the cloud. That’s a little too Big Brother for our tastes, but we can see his point about how wasteful just a few minutes of idling can be when spread over a huge population of vehicles. This hack might make a nice personal reminder to correct wasteful behavior. It could even be rolled into something that reads the acceleration and throttle position directly from the OBD port, like this Internet of Cars hack we featured a while back.

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The OpenR/C Project

The Open RC Truggy that started it all.
The Open RC Truggy that started it all.

[Daniel Norée] started the OpenR/C project back in 2012 when he bought a Thing-O-Matic. In search of a project to test out his new printer, he set his sights on a remote controlled car, which as he put it,”… seemed like the perfect candidate, as it presents a lot of challenges with somewhat intricate moving parts along with the need for a certain level of precision and durability.

After releasing his second design, the OpenR/C Truggy, he realized a community was forming around this idea, and needed a place to communicate. So, he created a Google+ group. Today, the Truggy has been downloaded over 100,000 times and the Google group has over 5,000 members. It’s a very active community of RC and 3d printing enthusiasts who are testing the limits of what a 3d printer can do.

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Adorable Matchbox Robot

[wattnotions] has been playing with matches, well the box they come in anyway. One day he was letting synapses fire unsupervised, and wondered if he could build a robot inside of a matchbox. His first prototype was a coin lithium battery and scrounged motors from those 3 US Dollar servos you can buy by the dozen. It scooted around just fine, but it drained the battery instantly and was a little boring.

Next, he etched a board. It had a little PIC micro, a connector for a mini LiPo, and an H bridge. It fired up just fine, and even though it drained the battery way too fast, at least it wasn’t brainless anymore. In our experience, robots tend to discard all the useful data they collect anyway, so being blind wasn’t too much of a problem.

Inspired and encouraged, with synapses gloriously undeterred, [wattnotions] set out to make a version 2. This time he ordered a board from OSHPark, made a 3D model in SketchUp, and proceeded to lock himself out from his own chip. Without a high voltage programmerhe was out of luck. The development was unfortunately put on hold.

It was fun to read along with [wattnotions] as he went on a small robot adventure. We hope he’ll complete a version 3 and have a swarm of the little fellows scooting around.

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String Racing Robots are Here !

This could be the start of a new thing. [HarpDude] showed off his String Car Racers over on the Adafruit forum. It’s like a small model cable car on caffeine. String up enough of them and go head to head racing with others.

A motor with a small pulley runs over a length of string stretched between 2 posts. Below the pulley, acting as a counterweight balance, is the rest of the racer. A Trinket board, motor driver, 9V battery and a pair of long lever micro switches to detect end of travel. The switches also help reverse the motor. A piece of galvanized wire acts as a guide preventing the String Car from jumping off the string. And discovering the benefits of a micro-controller design, as against discrete TTL/CMOS, old timer [HarpDude] added two operational modes via software. “Pong”, where the String Car keeps going back and forth over the string until it stops of (battery) exhaustion. The other mode is “Boomerang” – a single return trip back and forth.

We are guessing the next upgrade would be to add some kind of radio on the car (ESP8266 perhaps) and build an app to control the String Car. That’s when gaming could become fun as it opens up possibilities. One way to improve performance would be to add two “idler” pulleys in line with the main drive pulley, and then snake the string through the three of them. Now you know what to do with all of those old motors you’ve scavenged from tape drives, CD drives and printers. Let the Games begin!

Thanks [Mike Stone] for tipping us off on this.

Repairing a twisted prius display computer

This one is from way back in 2007, but the steps [hobbit] took to evaluate and repair a failed Prius Multi-Function Display (MFD) is a refresher course in how to go about fixing stuff that’s broken.

The 2004 / 2005 models of the Prius had peculiar problems with their MFD. Buttons and touch functions became sluggish and unresponsive, it wouldn’t display ECU data such as current and average fuel consumption, and couldn’t control stereo and air-conditioning. Lots of Prius users were reporting similar problems on the Priuschat forum.

The issues would usually arise long after warranty expired, and replacement units cost a couple of thousand dollars new. Toyota knew what the problem was (PDF link), but their fix involved swapping the defective units out.

[hobbit] managed to get a defective MFD unit from a friend, and because his own Prius still had a working MFD, he was able to carry out comparative tests on both units. The broken unit was generally laggy, and the buttons didn’t beep when pressed. Apparently, the AVCLan, a small data network between various components in the car, wasn’t reaching the MFD reliably. The MFD would send the “beep” command to the audio amplifier and wait for a confirmation that would never arrive. The system hung here until the MFD timed out.

In the end, the cause of the problem was the 60-pin micro connector that interfaces the two main boards of the MFD. Once the two are mated, tightening the mounting screws twisted the two boards ever so slightly, leading to flaky contacts.

The fix? [hobbit] tweaked all of the 60 pins outwards enough that they still made contact even when the connector housing got twisted. Comparing the defective MFD to the one in [hobbit]’s own car also demonstrated how the factory fixed the problem.

Thanks to [Nick] for sending in this tip, which he stumbled upon “while searching for ideas for a very small solder tip to repair something on my laptop.”

Tricking an Ancient Protocol To Play Tunes

A lot of technological milestones were reached in 2007. The first iPhone, for example, was released that January, and New Horizons passed Jupiter later on that year. But even with all of these amazing achievements, Volvo still wasn’t putting auxiliary inputs on the stereo systems in their cars. They did have antiquated ports in their head units though, and [Kalle] went about engineering this connector to accommodate an auxiliary input.

The connector in question is an 8-pin DIN in the back, which in the days of yore (almost eight years ago) would have been used for a CD changer. Since CDs are old news now, [Kalle] made use of this feature for the hack. The first hurdle was that the CD changer isn’t selectable from the menu unless the head unit confirms that there’s something there. [Kalle] used an Arduino Nano to fool the head unit by simulating the protocol that the CD changer would have used. From there, the left and right audio pins on the same connector were used to connect the auxiliary cable.

If you have a nearly-antique Volvo like [Kalle] that doesn’t have an aux input and you want to try something like this, the source code for the Arduino is available on the project page. Of course, if you don’t have a Volvo, there are many other ways to go about hacking an auxiliary input into various other devices, like an 80s boombox or the ribbon cable on a regular CD player. Things don’t always go smoothly, though, so there are a few nonstandard options as well.