Posts by Grant

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Robotic arm using Mini Maestro at the Nashville Mini Maker Faire

Posted by Grant on 4 December 2014

Inspired by this robotic arm tutorial, Andrew Hoover recently posted on our forum about a robotic arm he made for the Nashville Mini Maker Faire. The arm is constructed from laser-cut acrylic and actuated by hobby RC servos. The servos are controlled by a 12-Channel Mini Maestro, which reads the signals from joysticks and converts them to target positions using a Maestro script. You can see the arm in action in this video:

For more information on the project, you can check out Andy’s blog post for his robotic arm project, which includes a parts list, instructions, and code.

Candy bowl surprise

Posted by Grant on 24 October 2014
Candy bowl surprise

Anyone who has gone trick-or-treating has seen the house that puts a bowl of candy on the front porch and knows that there are those greedy trick-or-treaters who take more candy than they are supposed to. Well, if you are that person who puts the bowl of candy out on your front porch, you can make trick-or-treaters think twice before they take more than one piece of candy. In this project, I actuate a severed arm to slap down at the candy bowl whenever someone goes to reach into it. Continued…

Inflatable ghost

Posted by Grant on 14 October 2014
Inflatable ghost

After doing the creepy mask, I wanted to do something a bit more festive. This Halloween prop was inspired by those inflated decorations people put on their lawns. In this case, I wanted something a bit smaller since I wanted it to fit indoors. I also wanted to use one of our addressable 8mm RGB LEDs, so I could make it light up all sorts of colors instead of just a single color like I had often seen. I decided to make an inflatable ghost because I wasn’t sure I would be able to control the shape that well and figured a ghost would give me more leeway in shape. Continued…

Creepy eyes Halloween prop

Posted by Grant on 3 October 2014
Creepy eyes Halloween prop

In the lead up to Halloween, I thought it would be fun to make some Halloween-themed props; in particular, I was interested in making something creepy. What first came to my mind was one of those creepy portraits with moving eyes. To change it up a little, I decided to use a mask instead of a picture (which I thought would make it easier to hide the electronics). Down at a local store called Halloween City I picked up a cheap mask and some plastic eyeballs (though a more crafty person might just make their own mask and eyeballs). I made sure the mask was a bit stiff because I needed it to hold shape without actually having someone’s face in it. For the electronics in the project, I grabbed two sub-micro servos, a Micro Maestro, and a 4.8V battery pack. If you don’t have jumper wires it might also be helpful to get a pack of those, but this build only uses one to jump battery power to the Maestro’s logic power. Continued…

New products: Pololu Carriers with Sharp GP2Y0A60SZLF Analog Distance Sensor 10-150cm

Posted by Grant on 18 September 2014
Tags: new products
New products: Pololu Carriers with Sharp GP2Y0A60SZLF Analog Distance Sensor 10-150cm

3D rendering of the Pololu carrier with Sharp GP2Y0A60SZLF distance sensor.

We have released some simple boards over the past few weeks that were developed by our mechanical engineers (see earlier posts for Jon’s board and Brandon’s board). The board I got to design is a carrier board for the Sharp GP2Y0A60SZ 10-150cm analog distance sensor, which is a part we have been trying to get for almost five years.

While the board itself is simple, the GP2Y0A60SZ is exciting for us because it pretty much outperforms all of the other analog Sharp distance sensors. In particular, compared to the more expensive Sharp GP2Y0A02YK0F, which can also detect objects out to a maximum distance of 150 cm, the GP2Y0A60SZ offers half the minimum sensing distance (10 cm) and more than twice the update rate (60 Hz) in a much smaller package:

Sharp GP2Y0A02YK0F Sensor 20-150cm (left) next to Pololu Carrier with Sharp GP2Y0A60SZLF Sensor 10-150cm (right).

One application of these sensors that I am looking forward to is mini-sumo. The features on the sensor make them a great addition to a mini-sumo robot like the one I built for the LVBots mini-sumo competition last year. With these on my robot (the one with the Magikarp on it), I might be able to knock out a few more competitors the next time we have a competition.

5V and 3V versions available

Our sensor carrier is available in two versions: a 5V version for operation from 2.7 V to 5.5 V and a 3V version for operation from 2.7 V to 3.6 V:

For more information, see the product pages or check out our entire category of optical range finders.

Roboceratops - Robot Dinosaur

Posted by Grant on 12 August 2014

Robert Stephenson (blobbington) posted about his robot dinosaur, Roboceratops, on the Trossen Robotics forums. Roboceratops is a small robotic dinosaur built to resemble a member of the Ceratopsian group. It uses a total of 14 servos for movement that are commanded through two of our Mini Maestro 12-Channel Servo Controllers, which are controlled by serial commands from his custom hand held controller. The controller is directly wired to Roboceratops and uses an Arduino Mega 2560, an LCD screen and two 3-axis joysticks. Robert wants to improve his design by making it wirelessly controlled and battery powered, and he plans to eventually make Roboceratops autonomous.

Roboceratops is mainly constructed out of laser cut MDF, but the legs are made from aluminum square bar. Upholstery foam was added to the legs to make them look more like real legs. The case of the controller and the neat carrying case at the end of the video also appear to be laser cut.

New product: Aluminum mounting bracket for NEMA 17 stepper motors

Posted by Grant on 29 July 2014
Tags: new products

Our new stepper motor bracket is designed to work with typical NEMA 17-size stepper motors like our 42×48mm and 42×38mm units (including our 42×38mm stepper motor with 28cm lead screw). It is made from 3mm-thick black anodized aluminum, which makes it both light and strong, and slot cutouts allow for plenty of mounting flexibility.

For more information, see the product page.

TwoPotatoe balancing robot

Posted by Grant on 22 July 2014
TwoPotatoe balancing robot

TwoPotatoe is a customer-built balancing robot that in its latest form uses an Arduino Mega to receive commands from a custom-made controller via XBees and a Wixel to wirelessly send telemetry to a PC. The robot uses feedback from a MinIMU-9 v3 IMU module’s accelerometer and gyro to maintain its balance, and it uses the MinIMU’s compass to navigate. The drive system consists of two 37D mm metal gearmotors with encoders controlled by a VNH3SP30 motor driver carrier. Check out the video below of TwoPotatoe in action:

You can read more about how TwoPotatoe works in the how it works section of its site.

10 December 2014 update: The old video of Twopotatoe has been replaced with a newer one. TwoPotatoe has also undergone a few changes: Arduino Due instead of the Arduino Mega, new motor controllers, new personality, etc. For more information about the changes and to see some new pictures, check out TwoPotatoe’s website.

Apeiros robot Kickstarter

Posted by Grant on 15 July 2014

Abe Howell posted to our forum about a Kickstarter campaign for a robot he calls Apeiros. It is an open-source robot he designed as a teaching tool for STEM. Apeiros uses some of our parts and our laser cutting service in its construction. It is also designed to be upgraded with some of our sensors like the QTR-3 or QTR-8 reflectance sensor arrays or the Sharp GP2Y0D810Z0F Digital Distance Sensor. Some of the higher pledge rewards on the Kickstarter include these sensors. You can learn more about the robot on its Kickstarter page.

Hexapod robot running ROS

Posted by Grant on 9 July 2014

One of our customers made a hexapod that is controlled with a PlayStation controller. It uses our 18-channel Mini Maestro to command the servos and a MinIMU-9 v2 for stabilization. The hexapod’s movements are directed by a BeagleBone Black running Robot Operating System (ROS). The physical body of the hexapod is based on a Lynxmotion Phoenix design and was constructed by the customer. The project is well documented and more details can be found in the original post. However, the post is in Russian, so you might need to запустить страницу через переводчика.