Monday, July 23, 2012

Wixel Saves the Day!

I hate to admit to all of the TI wireless doodles that I have purchased that I have not been able to do anything with (the Chronos, the RF2500, the LaunchPad Anaren Air Booster pack, etc.) Most recently I tried to comprehend the Air Booster code: 40 files of interrelated dependencies, 4000 lines of code completely obstifucated: it is out of my league. As an avid hobbyist, I don't purchase hardware to run a pre-packaged demo; I want to use and adapt it to my own projects. In the 21st Century, I am perfectly content to let the radio be a little black box, an accessory to my microprocessor. There are popular solutions like Zigbee and BlueTooth modules at around $50 a piece; but any radio link would of course require a pair of them (exceeding even my self-indulgent hobby budget). I was so glad to come across the Wixel from Pololu. The price point is right at around $20 per transceiver, and they provide useful code that is ready to perform a job. All I wanted was an RF link to push bytes in one end and get them out the other; the Wixel sets this up in about a minute. For a quick and dirty test, I loaded the USB-to-Radio code in both Wixels. The code auto-detects whether it is plugged and powered from USB or a battery, so the unit plugged into the computer was easily controlled from a terminal program (Tera Term). The distant-end Wixel was run off of a 3V CR2025 battery. I soldered 2 right-angle header pins to P1_6 and P1_7 (Tx and Rx data lines) so I could plug and unplug a shorting jumper for a communication loopback. From my laptop terminal I typed ASCII characters, which were transmitted to the battery operated Wixel, which looped them back to the computer's display; thus evidencing full duplex communication. There is so much more that this transceiver can do. I plan on using it to upgrade my robot #7's remote control interface, so battery and sensor status can be received from my control point, as well as duplicating the functionality of my original RC rig.

Pololu Web site [Link]

Wixel Worksheet [Link]

My other interests [Link]