Miniscule Line-Follower

January 15, 2014 by Mike Szczys 16 Comments

miniscule-line-follower

Building line following robots is fun and easy. Building a line-follower that is this tiny is a different story. The surprising thing for us is that despite how it looks, this robot whose name is Rizeh doesn’t use wheels to get around. [Naghi Sotoudeh] built the line-follower using two vibrating motors, with needles (not shown above) making three points of contact with the ground.

His website is a little sparse, but hit the downloads page to get a PDF file that serves as the build log. We also downloaded the 32 second demo video which is worth it. The magic-marker track that the bot is circumnavigating isn’t any bigger than the palm of your hand!

Onboard the diy PCB you’ll find two GP2S04 IR reflectance sensors which detect the black line on a white paper. The power-up sequence spends a few seconds calibrating these sensors. Speaking of power, [Naghi] went with a lithium polymer cell from a Bluetooth headset. At the heart of it all is an ATtiny45 which uses its hardware PWM capabilities to drive the two motors.

Of course line-followers rank up there with self-balancers as our favorite robot projects. But by far the ones we love the most are the speed-run maze solvers.

R/C Rock Crawler Prepped To Become Stair Climbing Robot

January 15, 2014 by Adam Fabio 21 Comments

rc-robot-frame

[Starlino] is working on an autonomous mobile robot. Like many before him, he looked to the radio controlled car world for a base frame. He found a good candidate in a rock crawler model called “Mad Torque”. Crawlers have been around for years, but they’ve recently been getting more popular. As always, popularity leads to lower priced entry-level models, which puts this crawler at a reasonable price for a robot frame. As the name implies, rock crawlers are all about crawling. Relatively low speeds, locked differentials, four-wheel drive, and (optional) four-wheel steering.

Of course, [Starlino] had to test drive his frame out before tearing it down to install electronics. As long time R/C modelers ourselves, we can’t blame him. Testing uncovered one major problem. The Mad Torque wasn’t quite mad enough to climb the stairs in his house. The front tires would grab and pull over the first step, but the wheelbase wasn’t quite long enough for the rear wheels to grab hold.

[Starlino’s] solution was to extend the wheelbase. For most 4WD R/C cars or trucks this would be a major problem, as the motors are mounted amidships. An extended wheelbase would mean also extending the drive shafts or belts. This isn’t a problem with rock crawlers. Crawlers need to support huge amounts of suspension articulation. Rather than create complex drive linkages, the common design is to place an electric motor on each axle. This isn’t the greatest idea in terms of unsprung mass, but it does make for easy wheelbase changes. [Starlino] found that the design was so modular he could bolt a second chassis up to the original. The new rear chassis bolted to the front at the top shock mounts. An extra set of battery brackets formed a lower brace. The new extended truck was long enough to clear the steps, though it does still struggle a bit, as can be seen in the video. We think larger diameter tires might help a bit here. [Starlino’s] next step is to ditch the R/C unit and give this ‘bot a brain!

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Autonomous Quadcopter Fits In The Palm Of Your Hand

January 12, 2014 by James Hobson 24 Comments

[Horiken Engineering], which is made up of engineering students at the department of aerospace at the University of Tokyo have developed an autonomous quadcopter that requires no external control — and its tiny. By using two cameras and a sonar sensor, the quadcopter is capable of flying by itself due to its ability to process the data from the on-board sensors. To do the complex data processing fast enough to fly, it is using a Cortex-M4 MCU, a Spartan-6 FPGA, and 64MBs of DDRSDRAM. It also has the normal parts of a quadcopter, plus gyros, a 3D printed frame and a 3-axis compass. The following video demonstrates the quadcopter’s tracking ability above a static image (or a way point). The data you see in real-time is only the flight log, as the quadcopter receives no signal — it can only transmit data.

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Giving A Roomba Internet Connectivity

January 11, 2014 by Kevin Darrah 33 Comments

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What was supposed to be a fun 1-day build ended up turning into a 3-day journey full of close calls when [Arthur] decided to give his Roomba Internet Connectivity.

The Roomba, whom [Arthur] calls Colin, has been in service for a couple of years, and once he got his hands on the Electric Imp, he had just the project in mind. With embedded Wi-Fi and a 32-bit processor all in an SD Card form factor, the Electric Imp makes it very easy to add the “Internet of Things” to just about anything you can think of. [Arthur] wanted to gain control of the Roomba, so he tapped into the SCI (Serial Command Interface). Now he can read out the Roomba’s on-board sensor data including battery voltage, current draw, and even the temperature.

These are the kind of walk-through’s we love to see, because he did it in real-time, so you get to experience all of the “surprises” along the way. For example, he removed an external charging port to make room for the added components, but that ended up disabling the dock charger. Then he discovered that when the Roomba was charging, the input voltage to the Electric Imp breakout board was too high, so he had to introduce an intermediate voltage regulator. But perhaps the biggest bump in the road was when he accidentally brushed the Electric Imp breakout board along the Roomba’s control board while power was on. Luckily the damage was isolated to just one smoked — a simple FET. The project turned out great, and (today) Colin’s data is actually visible through a public Xively feed.

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Rex, The ARM-Powered Robot Board

January 11, 2014 by Brian Benchoff 21 Comments

REX

There are a million tutorials out there for building a robot with an Arduino or Raspberry Pi, but they all suffer from the same problem: neither the ‘duino nor the Raspi are fully integrated solutions that put all the hardware – battery connectors, I/O ports, and everything else on the same board. That’s the problem Rex, an ARM-powered robot controller, solves.

The specs for Rex include a 1GHz ARM Cortex-A8 with a Video SoC and DSP core, 512 MB of RAM, USB host port, support for a camera module, and 3.5mm jacks for stereo in and out. On top of that, there’s I2C expansion ports for a servo adapter and an input and output for a 6-12 V battery. Basically, the Rex is something akin to the Beaglebone Black with the hardware optimized for a robotic control system.

Because shipping an ARM board without any software would be rather dull, the guys behind Rex came up with Alphalem OS, a Linux distro that includes scripts, sample programs, and an API for interaction with I2C devices. Of course Rex will also run other robotics operating systems and the usual Debian/Ubuntu/Whathaveu distros.

It’s an impressive bit of hardware, capable of speech recognition, and machine vision tasks with OpenCV. Combine this with a whole bunch of servos, and Rex can easily become the brains of a nightmarish hexapod robot that responds to your voice and follows you around the room.

You can pick up a Rex over on the Kickstarter with delivery due sometime this summer.

Self-Balancing Robots Wobble, But They Don’t Fall Down

January 9, 2014 by Kristina Panos 7 Comments

[Trandi] can check ‘build a self-balancing robot’ off of his to-do list. Over a couple of weekends, he built said robot, and, in his own words, managed not to over-design it. It even kept the attention of his 2-year-old son for several minutes, and that’s always a plus.

He was originally going to re-purpose one of his son’s RC cars, but didn’t want to risk breaking it. Instead, he designed a triangular 3-D printed chassis to hold a motor and some cogs to fit both the motor shaft and some re-used Meccano wheels. [Trandi]’s design employs an MPU 6050 6-DOF IMU for the balancing act and is built on an Arduino Nano clone.

[Trandi] is controlling the motor with an L293D, which has built-in flyback diodes to minimize spikes. He found that the Nano clone was not powerful enough to handle everything, so he added an L7805CV voltage regulator. After the break, watch [Trandi]’s cute bot tool around on various types of terrain, with and without a payload.

Don’t have an IMU lying around? You don’t really need one to build a self-balancing bot, as this IR-based lilliputian bot will demonstrate.

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Mustachioed Rover Simultaneously Manly, Adorable

January 5, 2014 by Kristina Panos 24 Comments

[Rick], an Adafruit learning system contributor, is excited by the implications of STEM’s reach into K-12 education. He was inspired to design Red Rover, a low-cost robot that can be easily replicated by anyone with access to a 3-D printer.

This adorable autonomous rover is based on the adafruit Trinket microcontroller, but will also rove under the power of an Arduino micro. It really is quite simple—the Trinket drives two continuous rotation micro servos and pretty much any flavor of rangefinder you like. [Rick] tested it with Parallax PING))), Maxbotix, and Grove sensors, and they all worked just fine.

What’s truly awesome about Red Rover are the track treads. [Rick] initially experimented with flexible filament. While he had good results, it was not a cost-effective solution. What you see in the picture and the short video after the break are actually rubber bracelets from Oriental Trading.

The plastic part count comes in at seven, all of which can be printed together at once. [Rick]’s gallery includes both small and large chassis and three different servo mounts. The Red Rover guide builds on other adafruit guides for Trinket general use, servo modification, and Trinket-specific servo control.

Update: Added [Rick]’s demo video after the break!

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