Posts by Jon

You are currently viewing a selection of posts from the Pololu Blog. You can also view all the posts.

Khan Academy interactive continuous rotation servo demo

Posted by Jon on 28 November 2014
Khan Academy interactive continuous rotation servo demo

Khan Academy user mbbackus created a demo that allows users to visualize the effects of sending different pulse widths to the SM-S4303R and Parallax continuous rotation servos. (You can use the up and down arrow keys to change the pulse width, and more instructions can be found as comments in the code.)

For those who are interested, you can learn more about standard RC servo pulses in this series of blog posts about hobby servos.

You can see the demo on its Khan Academy page.

New products: Pololu T-shirts

Posted by Jon on 21 November 2014
Tags: new products

We have a new batch of T-shirts available, just in time for winter! These shirts are very similar to the ones we released in 2012, featuring a printed circuit board (PCB) design in the shape of the Pololu logo on the front and the Pololu slogan “Engage Your Brain” on the back.

The shirts are available in a variety of youth and adult sizes, and this time we have two new colors available in addition to our standard royal blue: cardinal red and charcoal gray.

You can find our full selection in our T-shirts category.

Raspberry Pi-controlled chicken coop

Posted by Jon on 6 November 2014
Raspberry Pi-controlled chicken coop

Forum user bennard posted about his WiFi-enabled chicken coop, which uses a Raspberry Pi to monitor and log data about its environment, serve a web page, send emails, and open and close the coop door. The system has sensors for detecting temperature, humidity, motion, and light, and includes a 50W solar panel and solar charge controller for recharging its batteries. The automated door is a hinged piece of wood that is connected to a linear actuator (via this mounting bracket) and controlled by a jrk 21v3 motor controller.

You can learn more about bennard’s project in his forum post.

Ascending/descending spider

Posted by Jon on 16 October 2014
Ascending/descending spider

This animated spider prop takes a traditionally static Halloween display to new heights! The setup is simple: a Maestro servo controller and a continuous rotation servo raise and lower a spider with the help of a limit switch. Continued…

Ghastly gas ghost

Posted by Jon on 9 October 2014
Ghastly gas ghost

This project turns a innocent-looking ghost decoration into an ambush in wait for unsuspecting passersby. The basic idea is straightforward: whenever someone walks within a few feet of the ghost’s face, it blasts them with a terrifying burst of compressed gas. Continued…

New product: Addressable high-density RGB LED strip

Posted by Jon on 24 September 2014
Tags: new products
New product: Addressable high-density RGB LED strip

Last December we started carrying addressable RGB LED strips based on the WS2812B LED driver. Since that driver integrates an LED and a driver into the same package, we were able to offer higher density strips than before.

We are excited to announce that we are now carrying an even higher-density WS2812B LED strip. This strip has 72 LEDs and is 0.5 m long, for a density of 144 LEDs per meter. It is also the shortest WS2812B strip we carry.

LED side of the WS2812B-based addressable LED strips, showing 30 LEDs/m (top), 60 LEDs/m (middle), and 144 LEDs/m (bottom).

A 1/2-meter, 72 LED addressable RGB LED strip on the included reel.

This LED strip, like the other WS2812B strips we carry, has both input and output JST SM connectors, which make it easy to connect multiple strips together. It is compatible with many popular microcontrollers, and we provide Arduino libraries to help you get started. More information about this LED strip, including how to use it, can be found on its product page.

You can also view our entire selection of WS2812B LED strips.

Leviathan: an autonomous Raspberry Pi-controlled electric boat

Posted by Jon on 11 September 2014
Leviathan: an autonomous Raspberry Pi-controlled electric boat

Heikki Leivo and Matti Koljonen are currently working together to develop a miniature autonomous electric boat, which they are calling Leviathan. The boat is made of polystyrene foam, uses brushed DC motors and servos for movement, and is controlled by a Raspberry Pi, which reads data from GPS and a MinIMU-9 inertial measurement unit for navigation. Leviathan is equipped with a camera and also features a D24V6ALV step-down regulator for powering servos and other electronics. The boat is also controllable over WiFi.

The electronics inside Leviathan.

Matti and Heikki plan for their vehicle to be able to run pre-defined routes, capture photos, and record video, among other things. You can learn more about Leviathan on its website.

New product: DRV8838 motor driver carrier

Posted by Jon on 5 September 2014
Tags: new products
New product: DRV8838 motor driver carrier

If you’ve checked out my company profile, you might have noticed that my focus at Pololu is on developing mechanical parts. So, I am particularly excited to reveal this basic board I designed! (Don’t worry, like Jan mentioned in this blog post, we have support structures for checking all of the work we do, so other experienced electrical engineers here assessed and contributed to my work.)

The DRV8838 motor driver carrier is the smallest motor driver we’ve made yet. With a motor supply range from 0 V to 11 V and the ability to deliver a continuous 1.7 A (1.8 A peak) to a single brushed DC motor, the DRV8838 is an exciting option for controlling any one of our plastic or micro metal gearmotors. (That includes the high power versions.)

For more information about this carrier, see its product page.

But Jon, why are mechanical engineers designing PCBs?

As our products get more sophisticated, we find ourselves wanting to integrate mechanical and electrical aspects of our design process. To give the mechanical engineers better perspective on what goes into designing electronics, we were each assigned a simple board to develop. We expect this to improve our all-around engineering abilities and also to lead to additional benefits for our customers, like better documentation and support.

Modding the Zumo: encoders, WiFi, GPS, USB, 120 MHz, and joystick control

Posted by Jon on 1 August 2014
Modding the Zumo: encoders, WiFi, GPS, USB, 120 MHz, and joystick control

Forum user Erich uses our Zumo chassis as a platform for teaching robotics, but instead of using the Zumo shield, he has been making his own custom electronics that let it do many more things. One of his most recent projects, which he describes in this forum post, involves a control board he designed that uses a Freescale ARM Cortex-M4F running at 120 MHz. He says it is capable of running WiFi, USB, GPS, and processing encoder signals in real-time.

His robot also uses a mini-sumo blade, Zumo reflectance sensor array, and a pair of 75:1 micro metal gearmotors with extended shafts connected to a pair of optical encoder boards.

Erich also used the ElecFreaks’ joystick shield to run his modified Zumo, which sounds like a lot of fun! For more information on this project, including some of the problems he had to overcome to get it all working, see this forum post or visit Erich’s website.

Erich has posted to our forum about his projects before; you can find a list of the forum posts he made that we blogged about below:

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

December 2013: Zumo Tournament Videos

May 2014: Optical Motor Shaft Encoder in Zumo with Signal Processing

Firetail UAV System

Posted by Jon on 25 July 2014
Firetail UAV System

We mentioned it in passing in an earlier post, but we think that the Firetail UAV System deserves its own post. Since then, Firetail’s creator, Samuel Cowen, has continued to develop this open-source UAV autopilot system, posting regular updates on his blog and sharing his project on the Pololu forum.

Firetail is designed to be installed in any fixed-wing RC airframe and autonomously fly up to 512 waypoints. The system includes software for a ground control station, which allows users to see the location, speed, altitude, and orientation of the aircraft. Users at the station can also upload and download autopilot settings and plan flights using Google Maps.

To test Firetail, he built his own RC aircraft, which uses an Arduino Due to process signals from an RC receiver, and reads data from an AltIMU-10. Depending on how the user sets up the autopilot mode, the Firetail system either flies the craft, or simply allows the user to fly the craft while streaming telemetry data to the ground control station.

You can learn more about the Firetail system on its website.