Low-Cost SBCs Could Revolutionize Robotics Education

For my entire life, my mother has been a technology trainer for various educational institutions, so it’s probably no surprise that I ended up as an engineer with a passion for STEM education. When I heard about the Raspberry Pi, a diminutive $25 computer, my thoughts immediately turned to creating low-cost mobile computing labs. These labs could be easily and quickly loaded with a variety of programming environments, walking students through a step-by-step curriculum to teach them about computer hardware and software.

However, my time in the robotics field has made me realize that this endeavor could be so much more than a traditional computer lab. By adding actuators and sensors, these low-cost SBCs could become fully fledged robotic platforms. Leveraging the common I2C protocol, adding chains of these sensors would be incredibly easy. The SBCs could even be paired with microcontrollers to add more functionality and introduce students to embedded design.

rover_webThere are many ways to introduce students to programming robot-computers, but I believe that a web-based interface is ideal. By setting up each computer as a web server, students can easily access the interface for their robot directly though the computer itself, or remotely from any web-enabled device (e.g., a smartphone or tablet). Through a web browser, these devices provide a uniform interface for remote control and even programming robotic platforms.

A server-side language (e.g., Python or PHP) can handle direct serial/I2C communications with actuators and sensors. It can also wrap more complicated robotic concepts into easily accessible functions. For example, the server-side language could handle PID and odometry control for a small rover, then provide the user functions such as “right, “left,“ and “forward“ to move the robot. These functions could be accessed through an AJAX interface directly controlled through a web browser, enabling the robot to perform simple tasks.

This web-based approach is great for an educational environment, as students can systematically pull back programming layers to learn more. Beginning students would be able to string preprogrammed movements together to make the robot perform simple tasks. Each movement could then be dissected into more basic commands, teaching students how to make their own movements by combining, rearranging, and altering these commands.

By adding more complex commands, students can even introduce autonomous behaviors into their robotic platforms. Eventually, students can be given access to the HTML user interfaces and begin to alter and customize the user interface. This small superficial step can give students insight into what they can do, spurring them ahead into the next phase.
Students can start as end users of this robotic framework, but can eventually graduate to become its developers. By mapping different commands to different functions in the server side code, students can begin to understand the links between the web interface and the code that runs it.

Kyle Granat

Kyle Granat, who wrote this essay for Circuit Cellar,  is a hardware engineer at Trossen Robotics, headquarted in Downers Grove, IL. Kyle graduated from Purdue University with a degree in Computer Engineering. Kyle, who lives in Valparaiso, IN, specializes in embedded system design and is dedicated to STEM education.

Students will delve deeper into the server-side code, eventually directly controlling actuators and sensors. Once students begin to understand the electronics at a much more basic level, they will be able to improve this robotic infrastructure by adding more features and languages. While the Raspberry Pi is one of today’s more popular SBCs, a variety of SBCs (e.g., the BeagleBone and the pcDuino) lend themselves nicely to building educational robotic platforms. As the cost of these platforms decreases, it becomes even more feasible for advanced students to recreate the experience on many platforms.

We’re already seeing web-based interfaces (e.g., ArduinoPi and WebIOPi) lay down the beginnings of a web-based framework to interact with hardware on SBCs. As these frameworks evolve, and as the costs of hardware drops even further, I’m confident we’ll see educational robotic platforms built by the open-source community.

Scott Garman, Technical Evangelist

This article was a preview of an upcoming interview in the February issue of Circuit Cellar. The full interview is now available here.
Garman_web

Scott Garman is a Portland, OR-based Linux software engineer. Scott is very involved with the Yocto Project, an open-source collaboration that provides tools for the embedded Linux industry. Scott tells us about how he recently helped Intel launch MinnowBoard, the company’s first open-hardware SBC. The entire interview will be published in Circuit Cellar’s February issue.—Nan Price, Associate Editor

NAN: What is the Yocto Project?

 SCOTT: The Yocto Project is centered on the OpenEmbedded build system, which offers a tremendous amount of flexibility in how you can create embedded Linux distros. It gives you the ability to customize nearly every policy of your embedded Linux system.

I’ve developed training materials for new developers getting started with the Yocto Project, including “Getting Started with the Yocto Project—New Developer Screencast Tutorial.”

MinnowBoardWEB

Scott was involved with a MinnowBoard robotics and computer vision demo at LinuxCon Japan, May 2013.

NAN: Tell us about Intel’s recently introduced the MinnowBoard SBC.

SCOTT: The MinnowBoard is based on Intel’s Queens Bay platform, which pairs a Tunnel Creek Atom CPU (the E640 running at 1 GHz) with the Topcliff Platform controller hub. The board has 1 GB of RAM and includes PCI Express, which powers our SATA disk support and gigabit Ethernet. It’s an SBC that’s well suited for embedded applications that can use that extra CPU and especially I/O performance.

MinnowBoardOWI_web

Scott worked on a MinnowBoard demo built around an OWI Robotic Arm.

The MinnowBoard also has embedded bus standards including GPIO, I2C, SPI, and even CAN (used in automotive applications) support. We have an expansion connector on the board where we route these buses, as well as two lanes of PCI Express for custom high-speed I/O expansion.

NAN: What compelled Intel to make the MinnowBoard open hardware?

SCOTT: The main motivation for the MinnowBoard was to create an affordable Atom-based development platform for the Yocto Project. We also felt it was a great opportunity to try to release the board’s design as open hardware.

OEM Host Adapter Flash Memory

Total Phase Aaardvark USB-to-I2C Host Adapter

Total Phase Aardvark USB-to-I2C Host Adapter

The Aardvark OEM Adapter is based on Total Phase’s Aardvark I2C/SPI USB-to-I2C adapter, which is a flexible tool for system design and testing. The new adapter is available in an I2C or SPI configuration and includes the Total Phase API, which enables you to create custom application GUIs.

The Aardvark OEM Adapter and API are cross-platform compatible with various OSes, including Windows, Linux, and Mac OS X. In a production environment, you can use the API for automated testing or device programming.

Contact Total Phase for pricing.

Total Phase, Inc.
www.totalphase.com

Two-Channel CW Laser Diode Driver with an MCU Interface

The iC-HT laser diode driver enables microcontroller-based activation of laser diodes in Continuous Wave mode. With this device, laser diodes can be driven by the optical output power (using APC), the laser diode current (using ACC), or a full controller-based power control unit.

The maximum laser diode current per channel is 750 mA. Both channels can be switched in parallel for high laser diode currents of up to 1.5 A. A current limit can also be configured for each channel.

Internal operating points and voltages can be output through ADCs. The integrated temperature sensor enables the system temperature to be monitored and can also be used to analyze control circuit feedback. Logarithmic DACs enable optimum power regulation across a large dynamic range. Therefore, a variety of laser diodes can be used.

The relevant configuration is stored in two equivalent memory areas. Internal current limits, a supply-voltage monitor, channel-specific interrupt-switching inputs, and a watchdog safeguard the laser diodes’ operation through iC-HT.

The device can be also operated by pin configuration in place of the SPI or I2C interface, where external resistors define the APC performance targets. An external supply voltage can be controlled through current output device configuration overlay (DCO) to reduce the system power dissipation (e.g., in battery-operated devices or systems).

The iC-HT operates on 2.8 to 8 V and can drive both blue and green laser diodes. The diode driver has a –40°C-to-125°C operating temperature range and is housed in a 5-mm × 5-mm, 28-pin QFN package.

The iC-HT costs $13.20 in 1,000-unit quantities.

iC-Haus GmbH
www.ichaus.com

AAR Arduino Autonomous Mobile Robot

The AAR Arduino Robot is a small autonomous mobile robot designed for those new to robotics and for experienced Arduino designers. The robot is well suited for hobbyists and school projects. Designed in the Arduino open-source prototyping platform, the robot is easy to program and run.

The AAR, which is delivered fully assembled, comes with a comprehensive CD that includes all the software needed to write, compile, and upload programs to your robot. It also includes a firmware and hardware self test. For wireless control, the robot features optional Bluetooth technology and a 433-MHz RF.

The AAR robot’s features include an Atmel ATmega328P 8-bit AVR-RISC processor with a 16-MHz clock, Arduino open-source software, two independently controlled 3-VDC motors, an I2C bus, 14 digital I/Os on the processor, eight analog input lines, USB interface programming, an on-board odometer sensor on both wheels, a line tracker sensor, and an ISP connector for bootloader programming.

The AAR’s many example programs help you get your robot up and running. With many expansion kits available, your creativity is unlimited.

Contact Global Specialties for pricing.

Global Specialties
http://globalspecialties.com