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Frédéric Jelmoni built a neat robot with a Raspberry Pi and a Zumo Chassis Kit. The Raspberry Zumo robot can be controlled over WiFi using telnet. The server on the Raspberry Pi is written in Python and uses the RPIO library to send signals to an SN754410 motor driver that drives the two 100:1 Micro Metal Gearmotors HP in the Zumo chassis. The server also controls an RGB LED and a buzzer. A stripped-down Logitech webcam attached to the front of the robot provides video that is streamed over the web using mjpg-streamer.
Erich, a professor at the Lucerne University of Applied Sciences and Arts in Switzerland, posted to our forum about their first Mini Sumo tournament, which took place this past weekend. The tournament was a part of Erich’s embedded systems programming class, for which he created a custom Mini Sumo robot platform for his students to modify. His robots use a custom PCB that mounts to the Zumo chassis kit and connects to the reflectance sensor array. Instead of an Arduino, his PCB uses a Freescale FRDM-KL25Z as the microcontroller board. Students customized the modified Zumos with their own sensors (we saw at least a few of them using our IR proximity sensors). 21 robots were entered into the competition, and a winner was determined over 5 rounds. Links to a competitor showcase video, several battle videos, and more information about the competition can be found in his forum post.
We are also excited to see a list of performance tweaks that Erich created for Zumo robots to be more competitive in Mini Sumo. We have made this available as a resource on the Zumo product pages.
While he was experimenting with our Zumo chassis, Erich posted to our forums a few times updating us on the progress of his modifications. You can follow his robot’s progression by visiting these forum posts:
March 2013: Zumo Robot with FRDM-KL25Z Board
September 2013: Zumo Robot with Pololu Plug-in Modules
October 2013: Zumo Robot with Pololu Plug-in Modules, assembled
We saw this robotic ping-pong ball collector by Will Jessop on the Raspberry Pi blog a few days ago. The robot uses the Pololu 30T Track Set, a Raspberry Pi, and a lot of custom electrical and 3d-printed mechanical parts.
Apparently, Will plans to put his robot into service at the office of his employer, 37signals. This is exciting for us at Pololu because 37signals is the originator and a major sponsor of the Ruby on Rails web framework, on which our website is built. And although we did not attend this year’s RubyConf, we are proud that some of our parts, as shown in the video above, made an appearance.
You can find detailed build information in Will’s ping-pong robot blog posts.
While our laser cutting machines can only cut two dimensional parts, there are easy ways to make three-dimensional designs out of flat, laser-cut parts. A simple way to achieve this is to create slots in the vector design to allow the two parts to slide together perpendicular to one another. Some may remember this technique from childhood arts and crafts; this easy tweak allows parts to be easily assembled and disassembled.
These Chandeliers by Nicole Ketchum were created using our 3 mm acrylic with a slot width of 1/8″. You can adjust the width of the slot depending on how snug you’d like them to fit. Since Nicole’s chandeliers are meant to be hung out of reach, a really snug fit wasn’t needed. With the holidays right around the corner, these could spruce up any room of your home!
For more details on using slots to fit acrylic parts together, be sure to check out Nicole’s project in our Custom Laser Cutting Gallery. More details about our custom laser cutting service can be found here.
Pololu forum user Martan recently released a project called Wireless Servo Widget. The project website says:
Wireless Servo Widgets allow you to control up to 64 slaves, with each slave controlling up to six R/C type servos. In addition, each slave can return 3 analog input values to your Raspberry Pi. Slaves have a range of about 50 feet from the master. Use them for home automation, robotics, model train controls, or whatever you want!
The Wireless Servo Widget is based on our Wixel Programmable USB Wireless Module. Martan wrote apps for the Wixel that use the packet addressing feature of the CC2511F32 chip to implement a round-robin protocol. He also made a Slave Widget Breakout Board which makes it easy to plug servos into the slave Wixels. All of this and more can be found on the Wireless Servo Widget website.
Halloween is just around the corner, and people are looking to make fun costumes. I recently took a couple of calls from customers who were looking to make Katy Perry-inspired costume dresses with spinning peppermints, following the instructions found on this RPF forum thread. Parts from Pololu used to make the dress included an enclosed 3-AA battery holder with a switch and a Solarbotics GM3 224:1 Gear Motor. However, we suggest substituting our 200:1 Plastic Gearmotor, which has similar performance but no back shaft that needs to be removed.
If you have a cool costume that uses our products, please feel free to share them in the “Share your projects” section of our Forum.
Geoff from Tabletop Robotics wrote a tutorial on how to build a Flipbot, a basic differential-drive robot that can keep on going even when flipped upside-down. A Wixel serves as the brains of the robot, and a second Wixel in the remote allows the Flipbot to be wirelessly controlled. In addition to the Wixels, the Flipbot uses a number of Pololu products, including:
- Two micro metal gearmotors
- 22T track set
- DRV8833 dual motor driver carrier
- MMA7361L 3-axis accelerometer
The accelerometer is used to determine when the robot is upside-down. Geoff’s tutorial has a full parts list and a diagram of how everything is connected; the complete source code is also available.
Thomas Schoch, of Essen, Germany, built a neat robot with a Raspberry Pi and a Zumo Chassis Kit. The PiBot-B is controlled by a custom iPhone app that communicates over WiFi to the Raspberry Pi, which is running lighttpd and PHP. A Python program uses the WiringPi library to send signals to an L293D motor driver that drives the two 100:1 Micro Metal Gearmotors in the Zumo chassis. The iPhone app displays video from the attached Logitech C300 webcam, and the robot has an integrated 8×8 LED matrix from Adafruit that indicates its state. In the future, Thomas plans to add sensors for obstacle detection and make the robot autonomous. We were impressed by several things:
- PiBot-B is very tidy, thanks in part to the USB cables that were shortened and modified using liquid rubber.
- The Raspberry Pi has only one PWM output so Thomas used two OR gates to select whether the left motor, right motor, or both motors receive the PWM signal.
- The write-up has some great photos and informative diagrams.
The PiBot-B page is written in German, but it has a link at the top to translate it into English using Google Translate.