Jay Doscher posted on his blog at Polyideas.com about his 2-axis solar tracker designed to provide the optimal amount of power output with a portable setup. In the build, Jay uses a Raspberry Pi A+ topped with our Dual MC33926 Motor Driver for Raspberry Pi to control the motion of the system, which is accomplished using a Concentric 4″ linear actuator with feedback. In lieu of a GPS unit, the tracker uses hard-coded longitude and latitude coordinates with Pysolar, an open-source Python library, to calculate the sun’s predicted position. The system keeps the solar panel pointed at the calculated position with the help of a Razor IMU from SparkFun. The video above is time lapse footage of a mechanical test of the system that shows the unit tracking the sun (although it is indoors).

In the picture above, you can see the Raspberry Pi and dual MC33926 driver board on the left and the IMU on the right. The Dual MC33926 Driver for Raspberry Pi fits on top of the Raspberry Pi mainboard, eliminating a lot of wiring and making it easy to use while also leaving the setup looking clean and organized. Additionally, the Dual MC33926 Driver for Raspberry Pi provides a set of three through-holes where an appropriate voltage regulator can be conveniently connected, allowing the motor supply to also power the Raspberry Pi. You can see one of our D24V10F5 switching step-down regulators mounted on top of the dual MC33926 driver board to serve this purpose in the picture above as well.

This project was also a 2015 Hackaday Prize entry and made it to the quarterfinals!

For more information about this project, see Jay’s blog post, which has additional photos and details including a parts list and links to his code.

Related products

	Pololu Dual MC33926 Motor Driver for Raspberry Pi (Partial Kit)
	Pololu Dual MC33926 Motor Driver for Raspberry Pi (Assembled)
	Pololu 5V, 1A Step-Down Voltage Regulator D24V10F5
	Glideforce LACT4P-12V-20 Light-Duty Linear Actuator with Feedback: 50kgf, 4" Stroke (3.9" Usable), 0.57"/s, 12V

Zippy is an RC balancing robot created by Larry McGovern. It uses an Arduino Nano to read pulses from an RC receiver and accelerometer and gyroscope data from an MPU6050. After processing that information, the Nano commands two ST motor driver development boards, which each control a 30:1 37D mm gearmotor with encoder. The whole system is powered by a 3S LiPo (brand: Zippy, of course!). You can watch Zippy scoot around on pavement below:

In the video description, Larry mentions that he modeled Zippy after the Balanduino robot, but we would like to highlight one noticeable difference: he used his own pair of wheels, which are mated to the output shaft of his gearmotors with our 6mm scooter wheel adapters! I had a major role in designing these, so on a personal note, it is especially exciting to see someone get a good use out of them. (It also looks like our stamped aluminum L brackets are used to mount the motors.)

Related products

	30:1 Metal Gearmotor 37Dx52L mm 12V with 64 CPR Encoder (No End Cap)
	Pololu Aluminum Scooter Wheel Adapter for 6mm Shaft
	Pololu Stamped Aluminum L-Bracket Pair for 37D mm Metal Gearmotors

Forum member spiked3, whom we previously posted about, has shared another robot with a custom laser cut chassis. The new robot uses his own custom Arduino shield, the S3-Pilot, which has sockets for an IMU and two of our MC33926 Motor Driver Carriers.

Custom Arduino shield created by forum member spiked3.

The MC33926 drivers control two 37D motors with encoders, and the encoder signals are processed by the Arduino. The robot also includes a lidar, PIXY Cam, and Raspberry Pi. The on-board IMU and encoders allow the robot to keep track of where it is and what direction it is facing, so spiked3 was able to implement a high-level interface for the robot that accepts movement commands like “go forward three meters” or “turn a certain number of degrees to the right”.

You can find out more about this robot and see some videos of it being tested on spiked3’s blog.

Related products

	MC33926 Motor Driver Carrier
	Custom Laser Cutting Service
	50:1 Metal Gearmotor 37Dx54L mm 12V with 64 CPR Encoder (No End Cap)
	50:1 Metal Gearmotor 37Dx54L mm 12V (Spur Pinion)

In March, I wrote a blog post about the Bohlebots robotics team winning the West German Robocup Soccer 1v1. Since then, the Bohlebots team has gone on to win first and third in the German Open Robocup Soccer 1v1 with their two robotics teams.

Bohlebots’ soccer robot.

Good job Bohlebots!

Many of the engineers and robot enthusiasts here at Pololu competed in the LVBots 2015 line following competition. (For house rules and details about how the competition was judged, see the LVBots line following rules page.) Unlike most of my peers this was my first competition at LVBots, so I thought it was fitting to name my robot “Newbie”. Newbie uses a servo to steer the front wheels, creating fluid movements in and out of turns. At least that was the plan; unfortunately, Newbie had complications. Continued…

My entry for the LVBots line following competition last month was a rehash of my line following robot from last year, Pinto. Unfortunately, my robot from last year robot never made it to the competition: while trying to get it to work last minute, it literally vibrated itself apart. I did not execute my ideas very well, but I still think my overall plan was not a bad one. Since I still had all the parts, I decided I wanted to revive the robot and try to follow through with my plan. Continued…

After branching off into maze solving, pushing into sumo, and finding our way through dead reckoning, we circled back and had another line following competition at LVBots. I started designing the Suckbot before the previous line following competition over a year before this one, but the design dragged on and there was no urgent push to get it finished without another competition. The robot is designed to suck itself down to the course so it can go faster. I was able to get it following lines and sucking, and I managed to post some middle-of-the-pack lap times, but there was some unexpected behavior when tuning the PID parameters just before the competition, and I think there’s quite a bit of room for improving the robot’s performance in the future. Continued…

I recently competed in the LVbots line following robot challenge, where I took third place with the fourth fastest robot (due to lucky placement in the bracket). This was my second line following competition. I learned some valuable lessons from my first competition, such as bigger motors are not always good for going faster, so I focused my build on making a lightweight robot this time. Continued…

A few weeks ago the local robotics club, LVBots, hosted a line following competition here at Pololu, and like many of the engineers here, I built a robot, which I named Oddish, for the competition. I really only started seriously working on my robot about a week before the competition, so when I made the final decisions about what components to use I aimed for simplicity. In the last year we have come out with several A-Star microcontroller boards that include switching regulators, so I thought it would be fun and simple to make a line follower using an A-Star as the brain and its built-in 5 V regulator to power all the other components. I chose the A-Star 32U4 Mini LV for its operating voltage range and size. Continued…

For the recent LVBots line following competition, my first instinct was to try to come up with some unique alternative design for a robot that would be competitive with the traditional differential drive robots. However, I knew the winning robot from the last LVBots line following competition (Mostly Red Racer) would be returning, and it had an impressive time to beat. I also remembered spending so much time designing and assembling the hardware for my last line following robot, that I ended up not having enough time to tune the PID coefficients and get the performance I was hoping for. After brainstorming a few ideas, I ended up deciding to keep it simple and make sure I had enough time to get a robot I was happy with, which I ultimately named “The Chariot” because of its shape. The Chariot ended up winning second place in the competition, which I was very happy with. Instead of focusing this blog post on how you can make your own version of The Chariot, I will try to explain my thought process throughout the design and build process, In other words, my hope is that after reading through this post, it will be clear why I chose the parts that I did. Continued…