Practical Arduino: News


	Slides and code from Justin Mclean's Arduino Miniconf talk Mon, Feb 15 2010: Filed under Cool Stuff Posted by Jonathan Oxer One of the many excellent presentations at the recent Arduino Miniconf in Wellington, New Zealand, was Justin Mclean's "Putting your device in the browser and on the web". Justin's talk demonstrated use of a Flash object in a browser displaying data acquired by an Arduino, and also controlling the Arduino based on user actions. It was a really impressive demo because the latency was so small: in one demo, quite rapid analog samples were pushed to a dynamically updating graph that scrolled across the screen. Justin has put his slides and example code up on his blog. He's also doing a talk at the Web Standards Group in Sydney on February 24th, so if you're in town make sure you go along. He's a great speaker with some excellent tech to demonstrate so it'll be well worth it.


	Standardizing comms for Arduino shields Sun, Jan 31 2010: Filed under Cool Stuff Posted by Jonathan Oxer A couple of weeks ago I came across Andrew Oke's interesting DIY Labs blog showing some of the cool stuff he's working on with Arduino. His main project is currently Arduarium (an Arduino-based aquarium controller) which looks really neat in itself, but what got my attention is a series of shields he has designed. One of the problems with typical shields is that not only do they use a wide variety of methods to communicate with the host, but most of the time they don't even indicate on the header which pins they use. This is a personal bugbear of mine that I've ranted about in the past, and often it renders shields mutually exclusive: if there's contention on the pins required you may not be able to stack certain combinations of shields together. Andrew's very sensible solution to this problem is to standardize on I2C comms between the Arduino and all shields, and to use consistent pin assignments. That way all you need to do is make sure each shield has a unique I2C address, plug them all together, and away you go. Check out these shields he's already designed: pH / ORP shield Port Expander shield I2C / SPI / OneWire shield RTC / EEPROM shield Very, very interesting. I'm seriously thinking about adopting Andrew's I2C / pinout standard for my own future shield designs. It would certainly be a big improvement on the current ad-hoc shield pinout situation if more people started using his idea consistently.


	Erdem's Google Reader keyboard Thu, Jan 14 2010: Filed under Cool Stuff Posted by Jonathan Oxer Reader Erdem Yildrimer emailed me a few days ago with a question about a key-bounce problem he's had with buttons he's using for the Virtual USB Keyboard project, and he's now solved that problem and finished assembling a virtual keyboard. The end result is rather funky! He's used a red Sparkfun cardboard packing box as the project case, and mounted nine buttons in it to let him control Google Reader using his custom keyboard. I love it! He's posted about it on his blog in Turkish: freeduino.gen.tr/2010/01/googlereader-klavyesi/


	ProtoStack AVR prototyping board updated Thu, Jan 7 2010: Filed under Cool Stuff Posted by Jonathan Oxer You know those really annoying ads where some random person says "I thought of making icons clickable, so Windows 7 was my idea!" as if they single-handedly wrote millions of lines of code and were gracious enough to allow Microsoft to use it? Yeah, I hate those ads too. I hate the way they pander to the egos of people who once had a random $OBVIOUS_IDEA that had only been thought of about 13.2 million times previously, and imagined that somehow they were the first person to ever think of it. Anyhoo, enough ranting. Coz this time somebody really did revise a product, and I really did think of it. But at least I don't imagine I was the first! Way back when I still had hair I did a video product review of ProtoStack's AVR prototyping shield. A couple of things I mentioned in the video were that it would be nice to have clearer marking on the power busses and a pre-defined power supply to save having to DIY a PSU on part of the prototyping area. Well, Daniel at ProtoStack has done it! He's taken an already very sweet board and dipped it in the magic water, and when he pulled it out it was even better than before. This is a brilliant board for prototyping with 28-pin AVRs, so if you like to roll-your-own Arduino prototypes you should definitely check it out: www.protostack.com/forum/blog.php?u=2&b=23&c=1 I'm not being paid for this post, honest. I just really like these boards.


	Video of rocket launch with Arduino payload Mon, Jan 4 2010: Filed under Cool Stuff Posted by Jonathan Oxer One of the projects I really wanted to include in Practical Arduino was Artemis (Arduino Rocket TEleMetry and Instrumentation System) designed by Andy Gelme, Luke Weston, Michael Borthwick, and Pete Yandell, with assistance and advice from a number of other Connected Community Hackerspace members. Last week a few of us managed to sneak off to a launch location near Melbourne and do a couple of launches with Artemis in a de-powered class-G rocket (to keep it under the airspace clearance limit) and a class-C carrying an Arduino Pro Mini with an accelerometer. We had 4 video cameras on the launches (two on tripods, two hand-held) and Andy has just posted some of the video he took on his iPhone. More video and info to follow once we've deciphered the GPS, pressure sensor, and accelerometer data collected from Artemis.


	Toddler + Arduino + Twitter = Twoddler Mon, Dec 14 2009: Filed under Cool Stuff Posted by Jonathan Oxer Thanks to @arjenlentz for pointing me in the direction of this project! Combining a Fisher-Price Activity Center with a couple of Arduinos and an XBee module allows it to sense activity and send Twitter updates as it is used. Creepy or cool? Read more on the original site to find out more.


	Knock-pattern door lock Wed, Nov 4 2009: Filed under Cool Stuff A work colleague just pointed out this cool project to me. It uses a piezo element to detect knocks on a door, and then processes the pattern to figure out if it matches a pre-set acceptable "secret knock". If the pattern is acceptable it uses a motor to turn the lock handle and unlock the door. The original project site is here but the traffic level seems to have knocked it offline, so in the meantime you can read more about it at Gizmodo and Make. Very nice work.


	Power monitoring system in under 4 hours Fri, Sep 18 2009: Filed under Cool Stuff Posted by Jonathan Oxer Apologies in advance if this sounds a bit like an ad. It's not intended to be, but I need to give some context which means mentioning a couple of companies. Yesterday I experienced a perfect example of the sort of rapid prototyping that Arduino makes possible. My company (Internet Vision Technologies) does web-based business process systems, online applications, data visualization, etc, and we're doing a bit of work at the moment with energy monitoring among other things. We're working with the clever folks at EkoLiving who are experts at collecting data from high-end power monitoring / management systems, but yesterday we needed a system to feed some semi-sensible data from multiple power circuits into an online datalogging system so we'd have something to display in our visualization front-end for demo purposes. I didn't need the sort of accuracy required for a utility-grade system used for, say, billing customers for their power usage, just something that would give some representative figures as a reference point with perhaps 10% accuracy. So I grabbed a couple of bits from Jaycar and put together this: I left the office at about 11:30am to head off to Jaycar where I grabbed three C-tick approved / 400A-rated current clamps, an LCD module, the box, and some 4mm sockets. Back home to use my workbench and add in some things I already had including an Arduino Duemilanove, a WiShield, a prototyping shield, some ribbon cable, and some miscellaneous M3 nuts and bolts. Fitted everything together and was back in the office in time for a 2pm meeting with the hardware 100% complete. Had the meeting, then back to my desk where about another hour later I had the software up and running based on the sampling and RMS calculations from jarv.org/pwrmon.shtml but with the addition of local display on the LCD and remote reporting via the WiShield to a web service. I've wired it up for 3 input channels because that's how many current clamps Jaycar had in stock, but of course the Duemilanove has 6 ADC inputs so I marked the case to fit 6 pairs of sockets and then only populated 3 pairs. I'll probably add the other 3 channels next week when the electricians come to the office to separate out the circuits in our switchboard to let us get all the current clamps in there. So, total time required from my "stuff it, I'm just gonna make one" remark to complete, functional system as you see it in the picture: well under 4 hours, including the trip to Jaycar to get the parts. Now that's rapid prototyping! And that's why I love Arduino.


	Pneumatic control with an Arduino Thu, Sep 17 2009: Filed under Cool Stuff Posted by Jonathan Oxer A couple of weeks ago Steve Outtrim sent me a link to a story about a rather cool kitchen company called Anvil Motion, and from the moment I saw the demo video I knew I had to have a go at doing something like that myself. The sysadmin here at IVT, Dave Hunter, used to work for SMC so he has a lot of random pneumatic data stored in his skull and we started plotting how to make it work. The result is that I've just taken delivery of a few rather snazzy pieces of hardware including these: The cylinder at the top is a 20mm bore, 80mm travel dual-action (ie: extend and retract) unit fitted with adjustable reed-switch travel limit sensors. Just below and to the right is a solenoid valve with an inlet (bottom right) and two outlets (top left). It also has a pair of noise-reducing fittings on the vents. With the solenoid inactive air is directed out one outlet: solenoid active switches it to the other outlet. It's a 24V unit so controlling all this shiny hardware (real hardware, not just computer "hardware"!) will be a piece of cake for an Arduino and a relay. So the plan is to combine this with something like a one of these infrared proximity sensors from Sparkfun so that I can wave my hand near a kitchen cabinet and have the door magically open. If I can get that working I'll have a go at doing drawers as well. The big trick, though, is going to be putting this hardware aside and not touching it again until after Practical Arduino is finished! Always so many projects, so little time.


	Pan / tilt mount controlled with a joystick Tue, Sep 1 2009: Filed under Cool Stuff Posted by Jonathan Oxer Gluing together a mount for a touchscreen today I had a bit of time waiting for the epoxy to cure, and since I received a pan/tilt kit from Seeed Studio last week I took the opportunity to stick it together and connect it to an Arduino Mega. Not that it needs a Mega, but it happened to be sitting right in front of me and I couldn't be bothered moving! The two servos are controlled using PWM outputs, and an analog joystick from Sparkfun is fed to two analog inputs. The result: pan/tilt control from a joystick. It was trivially easy and took all of about 5 minutes to get going including plugging in all the jumpers for the joystick. The code is up now on github to show how easy it is: github.com/practicalarduino/PanTiltControl/