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[Des] sent in this really cool writeup on building a Regenerative receiver using VFDs. Regenerative receivers are basically short wave radio receivers that use positive feedback to more finely tune the signal. Though they can be built with modern components, [Des] wanted to try to make something that not only looked like it was made in the 30′s, but actually used the same technology. He utilized some VFDs in various places where vacuum tubes were needed. After building, [Des] found that the unit performed very well, better than his authentic 30′s radio that he compared it with. Those VFD’s seem to be everywhere recently. We did the story on using them as amplifiers, and and building display drivers for them too.
Ultrasonic rangfinders are a cheap and easy way to gather obstacle avoidance data. When added to a servo motor they form something of a scanning radar for near-proximity objects.
In this implementation, [Rui Cabral] is driving the servo, and collecting data from the sensor using a PIC 18F4520. The servo rotates 180 degreees, taking sensor measurements in increments of nine degrees. If it discovers obstacles, the distance and orientation are recorded. Feedback is displayed on a 20-LED bar graph display which shows a moving LED to track the sensor orientation, with LEDs remaining lit whenever an object is found. Right now the obstacle data is pushed over a serial connection with a PC, but could easily be injected into navigation logic for a robot in order to triangulate a path around the obstruction. You can see [Rui's] project in action after the break.
We looked in on the same concept with a different display technique a couple of years back. That hack used an Arduino and Processing to map sensor data with a traditional green sweep display.
[Thanks Oryx]
Swarm robotics is really starting to produce some interesting results. This image is from the video embedded after the break that show a group of five robots creating a landing platform for a quadrotor helicopter. The four that actually make up the platform are not in contact with each other, but instead following commands from the leader. We’re impressed by the helicopter’s ability to target and land on the moving platform. Takeoff appears to be another issue, as the platform bots stop moving until the quadcopter is airborne again.
These robots are part of a Graduate project at Georgia Tech. [Ted Macdonald] has been working along with others to implement an organizational algorithm that guides the swarm. The method requires that the robots have an overview of the location of all others in the swarm. This is done with high-speed cameras like we’ve seen in other robotic control projects. But that doesn’t discourage us. If you already have a flying robot as part of the swarm, you might as well add a few more to serve as the eyes in the sky.
[Thanks Supertroopa via Engadget]
If you’ve ever looked at one of [Todd Harrison’s] teardown or how-to videos closely, you would likely notice that his work bench looks like a standard hacker workspace. While we all try to keep our work areas clear of clutter, it’s not uncommon for components to pile up, cords to tangle, and things to get messy. [Todd] decided it was time to get a bit more organized, so he recorded a video showing how he went about the process.
Part of [Todd’s] work revolved around adding shelves to his bench so that he didn’t have measurement equipment stacked on top of one another. He also spent a good amount of time adding 30 additional plug sockets to his work space, replacing the single socket he had been struggling with for years.
Obviously this is not really a hack in and of itself, though this sort of reorganization is an important to efficient hacking all the same. We like the fact that [Todd] took the time to explain his process and materials in great detail – it will no doubt be helpful to those new to hacking.
Continue reading to see [Todd's] video in its entirety, or swing by his blog for more pictures and details.
A signal generator is a handy bit of kit and with the right components, it’s pretty easy to build one. Fabricating a proper signal generator probe is another matter entirely. [Frank]‘s DIY signal generator probe does exactly what it claims to, and is very cheap to boot.
After [Frank] made a simple signal generator with a few parts he had lying around, he needed a probe. Not wanting to deal with poking loose wires around his circuits, he decided to modify a scope probe. Six dollars and two weeks later, [Frank] had a suitable scope probe on his doorstop shipped from halfway around the world.
The strain relief on the probe was removed, and the resistors and trim cap on the PCB was desoldered. All that was left to do was solder a piece of wire from the BNC jack to the probe lead. The strain relief was put back on and clearly labeled for use as a signal generator probe. Not bad for 10 minutes of work.