Posts tagged “community projects” (Page 6)
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One of our customers, Jochen Alt, built a robot that balances on top of a ball by driving around on it with omni-wheels. Even better, he very thoroughly documented the project on GitHub! The robot uses a number of parts from Pololu including 37D mm metal gearmotors with encoders, stamped aluminum L-brackets for 37D mm metal gearmotors, and three VNH2SP30 motor driver carriers.
A good overview of the robot and the control system are on his Hackaday project page.
A technical paper about hydrofoil design by members of the Cedarville University Solar Boat Team won a $1,000 Honorable Mention in the 2016 Mandles Prize for Hydrofoil Excellence from the International Hydrofoil Society. The boat they’ve been building uses a few Pololu Jrk 12v12 USB motor controllers to drive linear actuators that control the hydrofoil angle of attack which controls the boat’s flight. (Yes, flight: a hydrofoil boat uses wing-like hydrofoils that lift up the hull as they “fly” through the water.) They plan to enter this boat in the “Top Class” of the Dutch Solar Challenge. The “Top Class” provides entrants the opportunity to design every aspect of their solar-powered boat, which they will use in a series of sprint and endurance races over the course of five days. They also plan on racing in the Solar1 Solar Boat World Championship at the Yacht Club de Monaco.
Congratulations to Matthew Siracusa and William Rule who placed first in the Robot Arm competition of the Science Olympiad SE PA Regional Tournament last Wednesday! They used our custom laser cutting service to cut the base and structural components of the robot arm out of black ABS. We wrote about another one of Matthew’s projects on this blog when he made a 6-string banjo (that has a frame we also laser cut) as part of the 2014 Science Olympiad.
The Science Olympiad website has more information about the Robot Arm competition.
@MarcisShadow is working on a project using a Raspberry Pi with a Pololu DRV8835 Dual Motor Driver Kit for Raspberry Pi to control a Celestron NexStar GoTo Mount, allowing web-based control of a telescope. He also uses a Pololu 5V Step-Up/Step-Down Voltage Regulator S7V7F5 connected to the motor driver to power the Raspberry Pi from the motor power supply.
The project is being documented in a multi-part series on DirtyAstro.com. Part 1 covers the electronics that come with the telescope mount, part 2 is about assembling and testing the DRV8835 driver kit and motors, part 3 tackles setting up the Raspberry Pi and using an SSH client (PuTTY) to connect to it remotely via a PC, and part 4 is about getting Node-Red running to program the Raspberry Pi graphically using a web interface from any machine on the network.
He is not finished with the project, but I have a couple of suggestions for him or anyone doing something similar: First, since his 12 V supply exceeds the maximum operating voltage of both the motor driver (11 V) and the regulator (11.8 V), I would recommend using different ones. Keep in mind that “wall-wart” DC power supplies, especially older transformer-based ones, can have a voltage significantly higher than the rated voltage. Second, a board running a full operating system is usually not great for timing-sensitive operations like counting encoder ticks. If it can’t keep up with the pulse rate, I would recommend using a secondary microcontroller for the encoders. One possibility would be to use the A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge, which incorporates a more appropriate 5.5 V – 36 V regulator, an Arduino-compatible microcontroller, and dual motor controllers.
This animated C-3PO replica, made by one of our customers, moves its eyes, arms, head, and—in true C-3PO fashion—tells tasteless jokes. The movements are animated by a Pololu Mini Maestro 18-channel USB servo controller. A Pololu RC switch with relay (controlled by the Maestro, not an RC transmitter) shuts off the power to the head to avoid servo humming noises. (You can achieve a similar result with most servos by not sending RC servo pulses, which a Maestro does when the servo target is zero.)
The customer’s C-3PO web page has more videos and extensive documentation on how the replica was built.
One of our customers, “Bartman” on the dronevibes.com forum, has made a video of himself planning his build and a forum post that explains how he built his quadcopter. He was inspired by the DJI Inspire 1, which raises its struts to get them out of the camera’s way. Bartman proposes a lighter and cheaper arrangement: when flying the quadcopter in its semi-autopilot “carefree” mode, he switches yaw control from the pilot to the camera operator. This gives the camera operator panning (via the entire copter’s yaw motion) without the need for a separate panning mechanism. He uses a Pololu RC multiplexer to achieve the control switching.
A close-up of the RC mux on Bartman’s multi-rotor.
More details and discussion are in the forum thread.
It only took two years but finally the automatic monitor is PERFECT pic.twitter.com/NTG5CiShqT
— Raph Koster (@raphkoster) February 19, 2017
Customer Raph Koster made this slick automatic rotating arcade cabinet display, which allows the arcade cabinet to easily switch from landscape to portrait depending on the game. The monitor is rotated by a servo controlled by a Micro Maestro 6-Channel USB Servo Controller. The Maestro is especially convenient for this type of project, because you can connect it to the computer using USB then control the servo using our command line utility
Raph shares his
usccmd scripts for automating the rotation along with a full parts list and extensive step-by-step build information in his forum post at ArcadeControls.com.
I am happy to bring some overdue attention to our customer who created TwoPotatoe, a balancing robot that I first wrote about on this blog a few years ago. This past fall, TwoPotatoe and his new robot ThreePotatoe competed in the Sparkfun AVC Competition. TwoPotatoe won first place for the 10 lb to 25 lb weight class. Check out the AVC video below! TwoPotatoe starts its run at about 53:00. ThreePotatoe won second place in the 25 lb to 40 lb weight class. Considering all the weight classes together, TwoPotatoe and ThreePotatoe scored third and fourth place overall, which is very impressive considering they were competing against four-wheeled robots that didn’t have to balance. ThreePotatoe’s run starts at about 1:08:30.
You can find more pictures and information about TwoPotatoe and ThreePotatoe in the AVC competition on the TwoPotatoe website.
Customer Guido Bonelli Jr., who is also the creator of the Dr.Duino Arduino shield, had us laser cut pieces of baltic birch for a unique piece of furniture for his home: a large, interactive puzzle. An Arduino Mega 2560 R3 controls the various puzzles and contraptions packed into this piece. His article in Design News goes into more detail including a parts list and more pictures.
One of our customers posted about his balancing robot on our forum. A Raspberry Pi Model B is the central controller for the robot. It communicates with a RoboClaw motor controller for motor control and measures the angle and angular velocity with a MinIMU v2. The RoboClaw also decodes quadrature encoder signals for measurements of position and velocity. The drivetrain is made entirely of Pololu parts: 37D metal gearmotors with encoders, brackets, mounting hubs, and wheels.
The robot’s control algorithm allows it to correct for both positional and angular disturbances, and it can be controlled wirelessly. To develop the control system, this robot builder measured the step response of the motors using the encoders.
For more details about how the control system was developed, see the forum post.