mbed and a few resistors runs console, VGA, and PS/2

[Jordan] writes in to show us a project he has been working on called MbedConsole. Living up its name [Jordan] has managed to run a 640×480 VGA output, PS/2 port and console all from the mbed itself. We really mean from an mbed only; no extra hardware is required aside from a few resistors and connectors, a VGA monitor and PS/2 keyboard. The code is open source and links are included in the blog. There are even instructions for including your own graphics.

There are a few things to tackle still, like SD card support. Currently the PS/2 keyboard lights for caps-lock are not functional. [Jordan] would love to know what else we’d see going on something like this, with 400k of flash and 20k RAM left there certainly is a bit of room for some interesting stuff. One of his main goals is to get rid of the C interface and port an interactive shell over that could do something like BASIC or Forth (to give it that retro environment feel). We have seen the mbed in a handful of projects, what do you think?

Automating household devices with Google Calendar

[Shane] is building a new house and wants some, “subtle home automation” as he calls it. His first project is hooking up a small heater to the Internet, and judging from his demo video everything is going swimmingly.

[Shane]’s project is built around an mbed microcontroller that connects to the Internet via an Ethernet connection. The mbed has a temperature controller and a solid state relay to turn the heater on an off; simple enough, but we really like how easily [Shane] connected his project to Google Calendar.

After looking over the Google API, [Shane] was understandably overwhelmed. He figured out that by syncing the mbed’s clock to network time and sending a GET request for one minute in the future, the mbed would always know what was scheduled with a minimal delay.

Now, all [Shane] does to turn on his heater is schedule a time and temperature in Google Calendar. He can do this from across the globe or country and makes for a really slick part of a home automation system.

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Short and squat balancing bot is extremely stable

[Lauszus] really put together an impressive self balancing robot platform. It is virtually motionless when balancing in place, and that stability is never lost even when motoring across the room.

Part of the success behind this build is the use of quality components. He’s got a really nice set of motors with built-in encoders which give feedback to the balancing system. They work in conjunction with a gyroscopic sensor and PID code to keep the two-wheeled platform upright. An mbed board running 96 MHz provides plenty of computing power for the balancing system. But an Arduino can also be found on board. This was included to facilitate Bluetooth connectivity with the remote control as [Lauszus] didn’t want to port the code he had already written.

The fourteen minute video after the break shares the details behind how the PID controller is tuned and how [Lauszus] implements target angle and a few other factors. Of course he talks about the hardware choices, and demonstrates functionality by driving the bot around using a wireless PS3 controller.

The construction method which uses masonite strips and threaded rod does a good job of protecting the hardware mounted on it. We’re always a bit worried about these bots falling over and some of the projects we see offer little or no protection. Once thing that helps protect against a spill is a piezo buzzer which sounds when the battery is getting low.

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USB slingshot controller is for the birds

This USB slingshot controller really brought a smile to our faces. Part of it is the delightfully silly promo video you’ll find after the break. [Simon Ford] combined nature and technology to bring this USB-enabled slingshot into existence.

The frame itself is from a branch he found in the Epping Forrest of London. He whittled away the bark, and hollowed out an opening in at the base of the ‘Y’ to receive an accelerometer board. It has a pair of female pin headers to interface with the mbed seen in the image above. But the real hack here is the code he wrote to translate accelerometer data into appropriate mouse movements. His success in the area makes this translate the virtual world of Angry Birds in a visceral experience of killing things with a slingshot.

We’re suckers for this type of project. Two examples that pop into mind are these musical instrument hacks for Rock Band 2.

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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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