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When properly modified for continuous rotation, hobby RC servos become an inexpensive, compact, easy-to-use actuator system for robotics projects, and servo manufacturers are increasingly answering the growing demand for such products with servos designed specifically for robots. One example is Power HD’s new AR-3606HB continuous rotation servo, which offers open-loop speed control rather than the closed-loop position control you typically get with a servo. It is the fastest and strongest continuous rotation servo we carry (up to 71 RPM and 93 oz*in of torque), with performance well suited for driving a small robot.
These basic boards conveniently break out the VBUS, GND, D-, D+ and ID pins of USB Mini-B and Micro-B connectors to a set of five 0.1″-spaced pins, making it easy to power your project from a USB port or to add a USB connector to your breadboarded USB microcontroller. The compact USB Mini-B Connector Breakout Board measures 0.55" × 0.85", while the even smaller USB Micro-B Connector Breakout Board measures 0.44" × 0.5" (including the USB connectors).
With the release of the new RC Switch with Digital Output and the new RC Switch with Small Low-Side MOSFET, our RC switch family overhaul is now complete. These compact modules convert hobby radio control pulses to digital on/off signals for use in RC switch and simple RC adapter applications. These products replace item #752 and item #1210, which have been put on clearance and will be discontinued when the remaining stock is gone.
For more information about these products and the rest of our RC switch family, see our RC Switch category.
The overhaul of our RC switch and RC multiplexer products continues with the new Pololu 4-Channel RC Servo Multiplexer. This compact four-channel multiplexer of hobby radio control pulses allows for easy switching between two independent RC signal sources. An auxiliary channel selects whether master or slave inputs show up on the four output channels. This makes it ideal for applications in which you have two possible control sources and want to be able to switch between them on the fly.
For more information about the new Pololu 4-Channel RC Servo Multiplexer, see the product page.
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:
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.
Here’s a sneak peek at some encoder wheels we are developing for our micro metal gearmotors:
I am happy to announce another price drop. This time, it’s for several of our QTR reflectance sensors!
QTR-8A and QTR-8RC reflectance sensor arrays are now $9.95 (down from $14.95) with quantity price breaks starting at just five units. These modules feature eight IR LED/phototransistor pairs spaced 0.375″ apart, and an integrated MOSFET allows the LEDs to be turned off for additional sensing or power-savings options. These boards can optionally be broken apart into a six-sensor array and a two-sensor array.
More about QTR sensors
These sensors and the rest of the modules in the QTR family combine infrared LED emitters with phototransistors that detect the amount of reflected IR. This makes them great for applications like edge detection and line following. Each type of QTR sensor is available in two versions: “A” units indicate the reflectance with an analog voltage, and “RC” units have digital I/O-compatible outputs that let you measure the reflectance by timing the discharge of a capacitor.
And don’t forget the newer members of our QTR family, which were priced from the outset in line with our efforts to offer better quality products at lower prices:
QTR-3A and QTR-3RC reflectance sensor arrays make a great minimal sensing solution for a line-following robot. They use smaller sensing elements than the QTR-1 and QTR-8 versions, so they can fit three IR LED/phototransistor pairs onto a compact 1.25″ × 0.3″ board.
QTR-L-1A and QTR-L-1RC sensors use a discrete right-angle infrared LED and a right-angle phototransistor, each mounted on a different side of the board. This results in a very small sensor that has a low profile along the plane of detection.
The Zumo reflectance sensor array incorporates six IR LED/phototransistor pairs onto a 2.6″ × 0.6″ board, with the distance between the sensors increasing as they get farther from the center of the array. This module was designed to work directly with the Zumo shield on our Zumo robot, but it can also be used as a general-purpose QTR sensor array.
We just added bulk stranded hook-up wire in six gauges (20, 22, 24, 26, 28, and 30 AWG) and six colors to our selection of cables and wire. With all the combinations, that’s 36 new options for wiring up your next project! The convenient mini spools are all filled, so the wire lengths range from 40 to 100 feet (12 to 30 meters), depending on thickness.
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