Investigating parking assist sensors

While his wife was out-of-town [James] jumped at the opportunity to do some snooping around with her Chevy Tahoe’s parking assist sensors. We can understand how pulling parts out of someone’s car would make them none too happy. But we find it hilarious that it’s a leased company car he’s tinkering around with. But we’re glad he did, the ten-page write-up he published about the project is a fascinating read.

You can see the control board above which is housed beneath the passenger seat. It uses a Freescale microcontroller to read from the four bumper-mounted ultrasonic sensors. But just looking at what parts are used obviously isn’t enough to satisfy a hacker’s appetite for knowledge. [James] busted out a CAN bus tool to sniff the data packets. These sensors use a custom chip designed by GM, utilizing a single wire communications system. He figures out the communication scheme and builds an mbed based test rig to read them directly.

[via Dangerous Prototypes]

Wicked use of HTML5 to display sensor data

This project shows you one possible way to use HTML5 to fully integrate sensor data from a microcontroller into our technological lives. Now, when we saw this tip come through our inbox we thought it would be an interesting example to learn from but we weren’t ready for how truly cool the setup is. Take a look at the video after the break and you’ll see that scanning the QR code on the project box will immediately start a 10ms resolution live stream of the accelerometer data. Furthermore, the browser page that the phone loads allows you to send what you’re currently viewing to the main frame of a browser running on a different computer with the touch of a button. In this way you can build a dashboard of streaming sensor data. Talk about the future of home automation. Imagine a QR code on your thermostat that allows you gain access to your home’s heating, air conditioning, humidifier, and water heater performance and controls just by snapping a pic? The sky’s the limit on this one so let us know what you’d use it for by leaving a comment.

In this case an mbed microcontroller is handling the data acquisition and pushing that to a server via a WiFly module using the WebSockets library. This data is pushed in the form of a JSON packet which is distributed by the server as a data stream. Clients can access it via a browser through a page that makes use of JavaScript.

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Dippy Bird binary clock

This Dippy Bird clock display is simple to build and it’s just waiting to be scaled up for use as a full clock. As shown there are only enough birds in this rendition to read out the hours. More tiers can be added for minutes and you could even add your own temperature readout function using a separate bird as the thermometer.

Other than the fact that there are only four bits of resolution, the first thing you should notice is that these birds have nothing to drink. They’re intended to dip their beaks into a glass of water, leading to evaporation that changes the temperature of the dichloromethane inside to start their teeter-tottering. Water isn’t used because the birds would be in constant motion. Instead a resistor has been placed in the base of each, which heats up when current is passed through it. A bird in motion is a digital 1, and bird at rest is a digital 0. A set of transistors protects the microcontroller from sourcing too much current. In this case an mbed is keeping time but any microcontroller will do. We’ve embedded a quick clip of the dippy bird clock after the break.

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Making oscilloscopes from ARM development boards

If you’ve got an ARM development board gathering dust in the corner of your shop, perhaps you could repurpose it as an oscilloscope. [Arend-Paul Spijkerman] was able to use an mbed and LPCXpresso as the hardware end of an oscilloscope. He didn’t use a standalone screen as a display, instead opting to push the scope readings from the hardware to a computer for display. This was greatly simplified by using StampDock as a basis for the GUI.

His circuit diagrams calls for an RS-232 connection for the LPCXpresso but not for the mbed. We’re not quite familiar enough with the mbed to know why, but perhaps those in the know can clue us in by leaving a comment. The probe connections are quite simple, each made up of a voltage divider and a pair of diodes. But the breadboard above looks much busier because it has two oscilloscope circuits built on it, and there’s a 10 MHz clock and a 4040 ripple counter which were used to provide a test signal.

Trobot: kickstarting the 6-axis minature robot arm

Having already made it to three hardware development versions, [Toby Baumgartner] is looking for some financial backing to make version four of this robot arm possible.

He’s modelling the arm after much larger ABB industrial robots. Like those, it mounts on a stationary base, and features movement along six axes.  The first couple of iterations even used ABB Software’s RobotStudio for control. This is the same software used by the full-sized robots, and features a special design language to integrate the robots into just about any production facility.

We don’t think the need for high-end software used with these small manipulator arms is very great, but we could see the finished product used for small-scale assembly line work some day. In the mean time these might be useful in your own projects. [Toby] has been using an mBed microcontroller board as the hardware driver. It communicates with the computer via an Ethernet connection and he’s even working on an Android interface right now.

Check out a video demonstration of version 2 and 3 embedded after the break.

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It’s like… I can tell the time just by the color, man

[Alex] has reduced the resolution of his timepiece as a trade-off for speedy-readability. At least that’s what he claims when describing his color-changing clock. It uses a ShiftBrite to slowly alter the hue of the clock based on the current time. The concept is interesting: 12:00 starts off at white and slowly fades to green at 3:00, blue at 6:00, red at 9:00, and back to white by 12:00 to start the process over again. He has gotten to the point where he can get the time within about 15 minutes just with a quick look. But he did need to spend a few days acquiring the skill by having the color clock sit next to a traditional digital clock.

The build is pretty simple and we’d bet you already have what you need to make your own. [Alex] is really just proving a concept by using the ShiftBrite and an mBed, there’s no precision RTC involved here. So grab your microcontroller of choice, and an RGB LED of your own and see if you can’t recreate his build.

Of course you could always choose to build a color-based timepiece that’s even harder to read.

Cotton candy just the color you like it

Hit the web to order up your custom-color cotton candy from this machine (translated). A computer monitors a web interface for an incoming order, then pushes commands to an mbed microcontroller which dispenses three different colors of sugar to whip up your custom shade of the cottony delight.

In addition to the sugar dispensing system, the candy maker itself is also a do-it-yourself design. It looks like the most difficult part of this project was getting this component right. They’ve got a collection of videos documenting the multiple attempts on the road to success. Once dispensed, the colored sugars make their way into a spinning metal cylinder where they’re heated by the flame from a butane candle lighter. Eventually the team manages to get cotton candy to form but we can’t help but feel like they’re trying to reinvent the wheel with this one.

[via Make]