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Digi MaxStream ZigBee Modules Enable Robots to Swarm

It sounds like it might come right out of a late-night sci-fi thriller, but the Surveyor SRV-1 has other plans than repressing its human creators and achieving world domination. In fact, SRV-1 "swarms" are being used by researchers and educational institutions in a quest to better understand sophisticated control and automation techniques using very low-cost robots.

Howard Gordon from Surveyor explained more about his application that uses Digi International MaxStream XBee-PRO wireless modules to relay data:

"The Surveyor SRV-1 is a small programmable wireless mobile robot with digital video camera and infrared sensors and fast 32-bit ARM7 processor. Operating as a remotely-controlled webcam or a self-navigating autonomous robot, the SRV-1 can run onboard C or BASIC programs or be remotely managed from a Windows, Mac OS/X or Linux base station with Python or Java-based console software, or controlled through the newly released Microsoft Robotics Studio. The console software includes a built-in web server to monitor and control the SRV-1 via a web browser from anywhere in the world, as well as archive video feeds on-demand or on a scheduled basis.

"The SRV-1 was designed as a research and education tool, especially for multi-robot 'swarm' applications. Video-enabled mobile robots have historically been quite expensive, and the SRV-1 provides a major breakthrough in cost, making it affordable for researchers to employ multiple robots in their projects. Additionally, the SRV-1 is one of the first small mobile robots to use video as its primary sensor, which creating the opportunity to develop new algorithms for video-based feature recognition, navigation and localisation.

"The ability to link the robots to a base station and to other robots is a fundamental requirement in our design.

We examined a variety of standards-based and proprietary wireless communications products, most seriously considering 802.11 and Bluetooth in addition to 802.15.4/ZigBee. While the ZigBee data rate was lower than alternatives, it provided adequate video frame throughput for our application, while providing considerably better range than Bluetooth and considerably lower power consumption and lower cost than 802.11.

"There were a number of ZigBee vendors to choose between, but the low-cost MaxStream development kits made it easy for us to evaluate the technology, and pricing of the XBee/XBee-PRO modules was very attractive. We were able to integrate the XBee-PRO radios with our robots very quickly.

"Because of this, we have a robust commercial-grade design at consumer-grade cost. In addition, we have assembled a rich set of open-source software tools that make this robot a good choice as a development platform for a variety of robotics research and education applications."

Désiré has been musing and writing about technology during a career spanning four decades. He dabbled in website building and web hosting when DHTML and frames were en vogue and started writing about the impact of technology on society just before the start of the Y2K hysteria at the turn of the last millennium. Following an eight-year stint at where he discovered the joys of global tech-fests, Désiré now heads up TechRadar Pro. Previously he was a freelance technology journalist at Incisive Media, Breakthrough Publishing and Vnunet, and Business Magazine. He also launched and hosted the first Tech Radio Show on Radio Plus.