Drawbot Software Aims To Do It Better Than The Rest

July 27, 2012 by Mike Nathan 7 Comments

drawbot-software

There are plenty of drawbot projects out there, many of which come with their own special software in tow. While some of these packages are easier to use than others, [Dan Royer] is pretty sure he can do it better.

Looking for a fun and engaging way to teach STEM subjects in schools across the country, [Dan] developed a relatively simple drawbot which can be constructed by a wide range of age groups. While he is trying to get schools to purchase his robot kits, we’re guessing that our readers would be more inclined to build their own.

So what does [Dan] have to offer that might interest you? Well, he says he has developed some drawbot software that’s pretty darn easy to use. Rather than multiple applications generating machine-specific code, his software will transform your picture into a line drawing in one easy step. The app uses a traveling-salesman algorithm to generate drawings with nary a crossed line in sight before outputting the resultant machine instructions in easy-to-use GCode.

We don’t have a drawbot of our own handy to test his software out, so if you do happen to give it a shot, let us know how it worked for you in the comments.

Shakey Robot Plays Angry Birds

July 24, 2012 by Mike Szczys 18 Comments

At this year’s Pycon [Jason Huggins] gave a talk about his Angry Birds playing robot. He built a delta robot which includes a pen actuator for controlling a capacitive touch screen. The video after the break starts with a demo of the bot beating a level of Angry Birds on the iPad.

The idea behind the build is that robots like this could be used for app testing. I this case [Jason] has tweaked the servo commands manually to achieve the results. But during the talk he does demonstrate some machine vision to analyze and win a game of tic-tac-toe.

We do enjoy seeing the robot, but we’re not sold on the thought that testing will use robots. Perhaps there is a niche need for this type of thing, but we assume the majority of automated testing can be done in the emulator for the device on which you are developing. What we really want to know is how the capacitive stylus works. We didn’t catch him talking about it at all. We want a reliable, yet simple way to electronically trigger touchscreen inputs (along the lines of this project). If you know how [Jason’s] stylus is working please share your thoughts in the comments section.

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Redesigning The RC Tank

July 21, 2012 by Jake W 6 Comments

[youtube=http://www.youtube.com/watch?v=–YZHMqHzPw]

[Vincent] started building this tank (translation) with a regular hobby model: the Heng Long Tiger 1. However, after considering some goals for the project, he decided to nearly gut the tank and redesign it, basing it on the Arduino and a standard Motor Shield. The possibilities with this setup are nearly endless. In its current form, the ArduTiger detects obstacles in front of it by way of three servo-mounted infrared rangefinders. The tank’s trajectory can be adjusted automatically based on feedback from the servo positions. Two additional short-range rangefinders detect if there is ground for the tank to roll over, keeping it safe from cliffs and black holes. [Vincent] plans on updating this beast by adding a Raspberry Pi for live video and advanced control… and maybe even adding a Geiger counter!

Robot Trash Can Catches Anything You Throw Near It

July 20, 2012 by Mike Szczys 56 Comments

This guy is about to toss the blue ball half way between the book shelf and the waste basket. By the time it gets there the waste basket will have moved into position to catch the ball perfectly. It’ll do the same for just about anything you throw.

We’re unable to read the captions but it looks like this may have been made as part of a commercial which is shown in the first few seconds of the video after the break. From there we see the development of a locomotive mechanism which will fit into the bottom of the bin. It start as a single swivel wheel, but gets more complicated quite quickly. Once the low-profile three-wheeler is milled and assembled it’s time to start writing the code to translate input from a Kinect 3D camera and extrapolate the position for catching the trash. The final result seems to do this perfectly.

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Self Balancing Robot Uses Cascading PID Algorithms

July 20, 2012 by Mike Szczys 24 Comments

At this point we’re beginning to think that building a self-balancing robot is one of the rights of passage alongside blinking some LEDs and writing Hello World on an LCD screen. We’re not saying it’s easy to pull off a build like this one. But the project makes you learn a lot about a wide range of topics, and really pushes your skills to the next level. This latest offering comes from [Sebastian Nilsson]. He used three different microcontrollers to get the two-wheeler to stand on its own.

He used our favorite quick-fabrication materials of threaded rod and acrylic. The body is much taller than what we’re used to seeing and to help guard against the inevitable fall he used some foam packing material to protect the top level. Three different Arduino boards are working together. One monitors the speed and direction of each wheel. Another monitors the IMU board for position and motion feedback, and the final board combines data from the others and takes care of the balancing. Two PID algorithms provide predictive correction, first by analyzing the wheel motion, then feeding that data into the second which uses the IMU feedback. It balances very well, and can even be jostled without falling. See for yourself in the clip after the break.

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Building An Autonomous Robot From An Xbox 360 Controller

July 20, 2012 by Mike Szczys 8 Comments

Wow, it’s amazing what [Carl] was able to build using an Xbox 360 control PCB as the base for his robot. His forum posts just touches the surface of the build, but he linked to a PDF file which has the full details.

This build basically attaches sensors and replacement motors to the controller board… and that is it! Some distance sensors are connected to the analog inputs for the left and right trigger. The whiskers use a couple of leaf switches soldered to controller button pads. The motors are geared replacements that use the same connectors as the rumble motors did.

The idea is that the controller is connected to a PC via the wireless radio it has on the PCB. Once the connection is made the PC software can read from all of the sensors and drive the motors accordingly. It would also be really easy to use a single-board solution like the RPi to do away with the need for a remote PC. But this is a fantastic start, and an approach which we had never before considered. See some video of the little guy getting around the room after the break.

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RC PVC Bot

July 19, 2012 by Mike Szczys 16 Comments

This hunk of PVC pipe is radio controlled. The wheels on the ends provide the locomotion, but it wouldn’t be going anywhere if it weren’t for that little tail strapped to the center of the tube.

When the motors are turning the body of the bot needs something to push against. In this case the tail hits the ground and keeps the chassis from spinning. We have seen attempts to go without a tail by using lopsided wheels to provide angular momentum, but this method is much more reliable.

The control for the bot is scrapped from a toy RC car. Once hooked up to the gearhead motors it’s ready to roll. The real difficulty of the build came in fitting everything into the pipe. A frame was built from a few disks used as mounting platforms which were separated by threaded rod. See it making its way around a gravel road in the clip after the break.

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