Using bluetooth in classroom

Joe Scaglione

Greetings,
I have a high school class running about 12 BoE-Bots and I would like to be able to wirelessly program and control them. I looked into the EasyBluetooth module and the XBee modules; they both seem like systems my students can handle, but I'm kinda leaning toward bluetooth. I was wondering if there would be interference problems using more than one bluetooth module in a classroom. Will the computer recognize only one bluetooth module and remain partnered with it? Any info or advice is greatly welcomed.

Mike Green

Bluetooth is designed to work in an environment with multiple pairs of devices all working at the same time. Each device has a unique address and pairs with another device with a unique address. They do interfere somewhat with each other in that two devices can attempt to transmit to the other of its pair at the same time and will have to retry the transmission, but that's part of the design of Bluetooth. It slows down the maximum data rate, but you probably won't notice anything. xBee has a similar design, but fewer addresses are available, still more than enough for your environment.

Joe Scaglione

Thanks, Mike! Another question: how do they handle networking with each other. I might try some swarming applications in the future, so the bots would have to talk to each other as well as the computers. Is this possible with bluetooth? XBee? Thanks.

Mike Green

Bluetooth is strictly pair based. One device talks to a specific other device (point-to-point networking). You can always close the connection and open a connection to another device.

With xBee, there are two different incompatible systems. You can replace one xBee firmware with the other system using a utility program, so the same hardware can be used with either system. 802.15.4 is used for point-to-point communications like Bluetooth while ZigBee is the system used for mesh networks where any particular message can be sent to any Zigbee device (using it's address).