Easy quadrotor helicopter instructions

Here’s a great tutorial on building your own quadrotor helicopter. This build isn’t necessarily less expensive than others we’ve seen since quality motors, propellers, and control circuitry aren’t cheap. But the design and assembly is well documented and presents a well-planned building procedure. The carbon-fiber tubes that make up the frame have extensions to protect the motors and propellers in the event of a crash. The Arduino, IMU, and transceiver are all tucked away between two aluminum body plates as well. They only thing missing is a solid methodology for tuning the four motors, a critical procedure that is just touched up at the end of the article.

Location tracking with Twitter and Google maps


[Ryan O'Hara] built a location tracker he could use on motorcycle trips. Ostensibly this is to give his wife piece of mind be we think that was an excuse to play with GPS and SMS. To stand up to the trials of the road [Ryan] took his breadboarded prototype to the next level, using a manufactured board and a SparkFun enclosure. Tucked safely away is a PIC 18F25K20 gathering longitude and latitude from a GM862, formatting the info into a Google Maps link, and sending it to the Twitter feed via an SMS message. If you’re not familiar with the GM862, in addition to being a GPS module it can send and receive cellular data on a GSM network.

This is a nice solid hardware platform from which we can envision a couple of other hacks. The feed could be parsed to make a nice map graphic like the webpage for that Twittering Road Bike. It also might be nice to have a d-pad and character LCD to post your own tweets to the feed at the end of the day.

Steroscopic rig requires only one camera

[courtervideo] shares an instructible with us on how to build a mirror rig to take stereoscopic pictures with one camera. We’ve had the thought “couldn’t you just do that with some mirrors?” when looking at a dual camera rig. Well, as we all suspected, you can. There are some advantages here, a single click gives you your 3d image or video without any post processing, and unless you just happen to have an extra camera lying around you can save money there. You do however lose some resolution compared to two separate cameras. This setup could actually add some steps if you were wanting to interlace your images for viewing on a 3d tv.

Serial port controlled CPU fan

[Christian] was running a Linux box as a home server but needed a way to quiet the noisy machine. Like many Linux servers, he’s using some pretty old hardware which doesn’t have an on-board header for the CPU fan which generates much of the unwanted sound. Those headers are nice because software can monitor the CPU and board temperature and adjust the fan accordingly.

[Christian's] solution was to use the serial port for the task. He built a small circuit in which serial pin 3 drives the base of a transistor, pin 5 provides ground, and a floppy drive power cable supplies 5 volts. From there he wrote a RUBY program to monitor the CPU temperature and generate a PWM signal on the serial port, throttling the fan speed as needed.

[CC Photo Credit: Garrette via Flickr]