Pololu Blog (Page 7)

Welcome to the Pololu Blog, where we provide updates about what we and our customers are doing and thinking about. This blog used to be Pololu president Jan Malášek’s Engage Your Brain blog; you can view just those posts here.

Jamee's dead reckoning robot

Posted by Jamee on 30 April 2014
Tags: lvbots
Jamee's dead reckoning robot

Several Pololu employees made robots for the LVBots dead reckoning competition. Unfortunately, my robot didn’t work enough in time for the competition, but perhaps the description of my robot might give you ideas for your own dead reckoning robot. Continued…

New product: Advancer Technologies Muscle Sensor v3

Posted by Jon on 29 April 2014
Tags: new products

Looking for a way to pump up your next project? Let the Muscle Sensor v3 from Advancer Technologies do the heavy lifting!

This small, easy-to-use, 1″ × 1″ board measures muscle activation via electric potential; this is referred to as electromyography (EMG). The sensor measures, filters, rectifies, and amplifies the electrical activity of a muscle; as the muscle flexes, the output voltage increases, resulting in a simple analog signal that can easily be read by any microcontroller with an analog-to-digital converter (ADC), such as our A-Star or an Arduino.

Muscle Sensor v3 with included hardware.

The engineers here were pretty excited to play with these when we got our first samples, as many of us hadn’t used anything like it before. While thinking of various ways to test the sensor, a few of us remembered this ridiculously awesome video of Terry Crews making music with his muscles. (Gets me every time! #MuscleEnvy.) Without getting ahead of ourselves, we decided to try something much quicker and more straightforward with some of our electronics.

In the demonstration video at the beginning of this post, you can see the muscle sensor in action as it measures the muscle activity of my bicep. The demo uses the muscle sensor with a Maestro servo controller to update the position of a hobby RC servo based on how hard I flex. The setup was very simple; the analog output signal from the muscle sensor is connected directly to channel 0 on the Maestro, and the two boards share a common ground. The muscle sensor is powered by two 1S LiPo batteries and the Maestro and servo (connected to channel 1) are powered from a separate 6 V battery pack.

Here I am modeling the correct placement of electrodes on my bicep for the Muscle Sensor v3.

The Maestro script we used is very similar to the “Using an analog input to control servos” example script provided in the Maestro user’s guide with a couple of modifications. We changed the scaling of the input channel (since our signal was from 0 V to 3.7 V) as well as the channel numbers to match our setup. The whole script is only a few lines long:

# Sets servo 1 to a position based on the analog input of the Muscle Sensor v3.
begin
  0 get_position       # get the value of the muscle sensor's signal connected to channel 0
  6 times 4000 plus    # scale it to roughly 4000-8092 (approximately 1-2 ms)
  1 servo              # set servo 1 accordingly
repeat

We can’t wait to see all of the amazing things you come up with when you engage your brain (and your muscles) with this sensor!

Maker Faire demo: automated treasure chest with jrk motor controller and linear actuator

Posted by Claire on 25 April 2014


Maker Faire demo: automated treasure chest with jrk motor controller and linear actuator

This blog post is part of a continuing series of blogs about the demos that Pololu displayed at our booth at Las Vegas Mini Maker Faire 2014. For more about the Faire and a video, see my previous blog post. This blog post will focus on our automated treasure chest demo. Continued…

New distributor: GarageLab (Doral, FL)

Posted by Paul on 25 April 2014
Tags: distributors
New distributor: GarageLab (Doral, FL)

We are happy to welcome GarageLab as a Pololu distributor! GarageLab, located in Doral, FL, is the US branch of our Brazilian distributor Laboratório de Garagem. They carry a wide range of Arduino, microcontroller, and robotics-related products, including their very own Arduino-compatible Garagino.

For distributors in your area, you can check out our complete list of almost 200 distributors.

New products: 10-20 AWG and 20-30 AWG wire strippers

Posted by Ben on 24 April 2014
Tags: new products
New products: 10-20 AWG and 20-30 AWG wire strippers

Inevitably, if you work with electronics long enough, you will encounter a wire that is too long, too insulated, or too connected (to the wrong thing), and while you might be able to MacGyver your way out of the situation with a pair of scissors or a suitably hardy set of teeth, nothing beats a good wire stripper. With that in mind, we set off in search of some good, basic wire strippers that would get the job done well without breaking the bank. Our favorites were a set of multi-purpose wire strippers and cutters that feature comfortably curved and cushioned grips and a nose that can be used as pliers. One version works with 10 to 20 AWG wires and another works with 20 to 30 AWG wires. (The stripping holes are labeled with the gauge of solid-core wire for which they are intended; for stranded wire, use the next larger hole.)

Wire stripper 10-20 AWG solid (12-22 AWG stranded).
Wire stripper 20-30 AWG solid (22-32 AWG stranded).

MiniTrack three-sided tracked robot

Posted by Grant on 24 April 2014

Let’s Make Robots user rhughes posted about MiniTrack, his custom-built tracked robot that features the ability to drive on each of its three sides. It uses our 30T track set and an extra pair of our 42×19mm sprockets. The tracks are driven by a pair of medium power 150:1 micro metal gearmotors, which are controlled by a DRV8833 dual motor driver carrier. MiniTrack also uses two Sharp GP2Y0D805Z0F digital distance sensors for object avoidance:

You can find pictures of various stages of the assembly of this robot and learn what else was involved in making it inside rhughes’s post.

Get a free A-Star 32U4 Micro with orders over $100!

Posted by Paul on 22 April 2014


We recently released the A-Star 32U4 Micro, an Arduino-compatible ATmega32U4 breakout board intended to be cheap enough to go into (and stay in) almost any project. To help our customers put A-Stars in everything, we are announcing a new, limited-time offer: on any order over $100, you can get a free A-Star 32U4 Micro with coupon code FREEASTAR.

Taking advantage of this deal? What are you planning to use your A-Star for? Please tell us about your project in the comment section.

Footage from quadcopter at LVBots

Posted by Paul on 18 April 2014
Tags: lvbots

This aerial video was filmed at an LVBots meeting on a DJI Phantom 2 quadcopter.

About LVBots

LVBots is a robotics club that has been meeting at the Pololu office in Las Vegas, Nevada for almost ten years. Our meetings are open to all ages and skill levels, and everyone is encouraged to bring their projects to share – even projects that are not capable of flying hundreds of feet into the air. Do you live in the area, or are you passing through? Check out our schedule and join us!

Maker Faire demo: Simple Motor Controller and Sharp analog distance sensor

Posted by Claire on 18 April 2014


Maker Faire demo: Simple Motor Controller and Sharp analog distance sensor

The Las Vegas Mini Maker Faire 2014 was on April 5th, and as you might have heard, we had a booth there with demos of our products. For more about the faire and a video, see my previous blog post. This post details the Simple Motor Controller and Sharp analog distance sensor demo that we brought. The demo was popular at the faire with both kids and adults, and though it is simple, it is a great tool for showing those who are just getting interested in robotics what one of the first steps to building a robot might look like. Continued…

PID line follower with 5" robot chassis

Posted by Claire on 18 April 2014

This PID line follower, originally featured in this Let’s Make Robots post by user Enigmerald, uses our 5" Robot Chassis along with 30:1 MP micro metal gearmotors, extended brackets, and our 42×19 mm wheels. Our QTR-8RC Reflectance Sensor Array is used to sense the line and our TB6612FNG carrier, along with an Arduino-compatible controller, is used to control the motors. A diagram of how everything is connected and the code for the robot are available in Enigmerald’s post. The post also has a link to a basic tutorial on PID tuning using the QTR array.