We have released a new build of the software for our Wixel Programmable USB Wireless Module that works on ARM Linux systems like the Raspberry Pi. This means that you can now upload apps to a Wixel from a Raspberry Pi, without needing a typical desktop computer. You can find the software download in the Wixel User’s Guide.

We have seen people use Wixels to help monitor blood glucose levels, create wireless quiz buttons, or wirelessly control servos. For a complete list of all the Wixel apps we know about, see the Wixel Apps list on our forum. We hope that the expanded software support for the Wixel will help people create new applications in the future.

Wixel programmable USB wireless module.

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	Wixel Programmable USB Wireless Module (Fully Assembled)
	Wixel Programmable USB Wireless Module
	Wixel Pair (Fully Assembled) + USB Cable
	Wixel Pair + USB Cable
	Raspberry Pi Model B+

Tomorrow is Pi Day (3/14/15 in the standard US date format of month/day/year), and we are celebrating by having a special overly-pi-themed one-day sale:

• Use coupon code PIDAY975 to get 31.4% off a 3pi robot (limit 3 per customer).
• Use coupon code PIDAY2753 to get a DRV8835 Dual Motor Driver Kit for Raspberry Pi B+ for $3.14 (limit 3 per customer).
• Use coupon code PIDAY to get 3.14% off your entire order (this discount is only valid for order subtotals between $3.14 and $314.16 and cannot be combined with other coupon discounts).

The sale is live now and runs through the end of tomorrow (midnight Pacific Time).

Thomas Schoch, who previously built the PiBot-B we blogged about, built another robot with a Raspberry Pi. His robot, the PiBot-A, uses our DRV8835 Dual Motor Driver Kit for Raspberry Pi B+ with a Raspberry Pi Model A+ to control two 100:1 Micro Metal Gearmotors. The robot also uses our S7V7F5 Switching Step-Up/Step-Down Regulator to supply the Raspberry Pi with 5 V from the motor power supply, allowing the whole robot to be powered form a single source.

The PiBot-A is controlled by a Web-App from Thomas’s iPhone. It communicates over WiFi to the Raspberry Pi, which is running lighttpd and PHP. The Python program on the PiBot-A uses the WiringPi library to send signals to the motor driver kit to drive two 100:1 Micro Metal Gearmotors that are connected to the chassis with our Micro Metal Gearmotor Brackets. Thomas also added an array of Sharp digital distance sensors to give the robot obstacle detection. You can find a video of the PiBot-A avoiding boxes below:

For a complete write-up of the robot, check out the PiBot-A page. It is written in German, but it has a link at the top to translate it into English using Google Translate.

11 February 2015 update: Thomas added support for our QTR-3A Reflectance Sensor Array to his PiBot-A to make a line follower and posted about it on Let’s Make Robots. The sensor array is interchangeable with the array of Sharp digital sensors used for obstacle detection. You can find a video of his robot following a line below:

Related products

	Pololu DRV8835 Dual Motor Driver Kit for Raspberry Pi
	Pololu 5V Step-Up/Step-Down Voltage Regulator S7V7F5

Stackable 0.100″ Female Header: 2×20-pin, Straight.

We now have special extended, stackable female headers for the Raspberry Pi:

• Stackable 0.100″ Female Header with Extra 0.3″ Spacer: 2×20-pin, Straight
• Stackable 0.100″ Female Header: 2×20-pin, Straight
• Stackable 0.100″ Female Header with Extra 0.2″ Spacer: 2×13-pin, Straight
• Stackable 0.100″ Female Header: 2×13-pin, Straight

The 2×20 versions work with the Raspberry Pi Model B+ (and the just-released A+), while the 2×13 versions match the I/O header on the older Raspberry Pi Models A and B.

See our Raspberry Pi category for our full selection of Raspberry Pi accessories.

Related products

	Stackable 0.100″ Female Header with Extra 0.3″ Spacer: 2x20-Pin, Straight
	Stackable 0.100″ Female Header: 2x20-Pin, Straight
	Stackable 0.100″ Female Header with Extra 0.2″ Spacer: 2x13-Pin, Straight
	Stackable 0.100″ Female Header: 2x13-Pin, Straight
	Raspberry Pi Model B+

The people at Seewald Solutions posted about their Raspberry Pi-based robot they call ToyCollect. Inspired by the creator’s daughter, who hides her toys under the couch, the robot is controlled via Android and can be driven under the couch to allow the user to view the hidden toys via a Raspberry Pi camera module and retrieve them. Along with a Raspberry Pi, the ToyCollect robot uses a Zumo Chassis Kit, 100:1 Micro Metal Gearmotors HP, Qik 2sv1 Dual Serial Motor Controller, and a Zumo blade to push the toys. The video below shows the robot in action (in German; subtitles available):

For more information, including the source code and instructions for building your own ToyCollect robot, see the ToyCollect post on the Seewald Solutions website.

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	Pololu Qik 2s9v1 Dual Serial Motor Controller
	Basic Sumo Blade for Zumo Chassis
	Zumo Chassis Kit (No Motors)
	100:1 Micro Metal Gearmotor HP 6V

We have a new video for our DRV8835 Dual Motor Driver Kit for Raspberry Pi B+. The video gives an overview of some of its features and mentions a few considerations for working with it. Check it out, and get some ideas for a cool Raspberry Pi robot!

Related products

	Pololu DRV8835 Dual Motor Driver Kit for Raspberry Pi
	Raspberry Pi Model B+

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.

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	Raspberry Pi Model B+
	Jrk 21v3 USB Motor Controller with Feedback
	Glideforce LACT12P-12V-20 Light-Duty Linear Actuator with Feedback: 50kgf, 12" Stroke (11.8" Usable), 0.57"/s, 12V
	Mounting Bracket for Glideforce Light-Duty Linear Actuators - Aluminum

We are now carrying a translucent enclosure for the Raspberry Pi Model B+!

Related products

	Translucent Enclosure for Raspberry Pi B+, 2 B, and 3 B
	Raspberry Pi Model B+

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.

Related products

	Raspberry Pi Model B+
	Pololu Step-Down Voltage Regulator D24V6ALV
	MinIMU-9 v3 Gyro, Accelerometer, and Compass (L3GD20H and LSM303D Carrier)

When the Raspberry Pi Model B+ was released last month, one of the most exciting features for us was the availability of a second hardware PWM output that can be used for motor control (previously, only a single hardware PWM output was available on the Model A and Model B). Two is a really useful number for robot builders, since that’s what you need for a basic robot platform, so we thought it would be a great time to make a dual motor driver kit for the Raspberry Pi.

The new Pololu DRV8835 Dual Motor Driver Kit for Raspberry Pi B+ is a minimal, low-cost motor driver expansion board based on the Texas Instruments DRV8835 dual motor driver, one of our favorite motor driver chips for small robots like the Zumo because of its excellent combination of size, cost, and performance. We carry a basic breakout board for this chip and just released an Arduino shield based on the DRV8835 last week.

Pololu DRV8835 dual motor driver kit (assembled) on a Raspberry Pi Model B+.

When assembled, the board plugs into a 2×17 block of pins on the Raspberry Pi GPIO header. Power and motors are connected to a separate block of pins, and you can use the included terminal blocks for easier wiring. The board takes an input voltage of 2 V to 11 V and provides two bidirectional motor channels capable of 1.2 A continuous or 1.5 A peak. You can also reconfigure the board for a single channel with twice the current.

Bonus feature – power your Raspberry Pi from your motor supply!

The Raspberry Pi requires a regulated 5 V supply, which is usually provided via the Micro-B USB power port. This is fine for a stationary setup, since you can just use a USB wall power adapter. On a battery powered Raspberry Pi-based robot, however, you need to somehow incorporate your own 5 V regulator capable of supplying about 500 mA. To help simplify your project, the motor driver kit includes a connection point for a three-pin regulator with the standard VIN-GND-VOUT pinout.

In the picture below you can see a complete setup using the motor driver board and our Step-Up/Step-Down Voltage Regulator S7V7F5 to drive two Pololu plastic gearmotors and power the Raspberry Pi from a set of four AA NiMH cells. This regulator is a good match for the range of input voltages of the DRV8835, though below about 4 V you might need something with higher current capability.

Driving motors with an assembled Pololu DRV8835 Dual Motor Driver Kit on a Raspberry Pi B+. A step-up/step-down regulator provides 5 V to the Raspberry Pi.

For more information, including schematics, pinout diagrams, and example Python code, see the product page.

Related products

	Pololu DRV8835 Dual Motor Driver Kit for Raspberry Pi
	Raspberry Pi Model B+
	DRV8835 Dual Motor Driver Carrier