Adding Bluetooth to Vex

[Joe Johnson]

Originally Posted by Blacklight

I'm working on a personal project....I'm an Telecomm. engineering student @ Egypt.

I got the kit,still building it, and had the idea of interfacing VEX byPC via bluetooth....

I'm totally new to the robotics scene...
I've gone through loads of Bluetooth modules and am not sure how to program them and connect them to the microcontroller?!

Any help would be much obliged, I'm a bit lost in this...

thanx

I believe this is possible.

#1 You will have to get the programmer for the VEX kit or build your own.

#2 I would get a bluetooth module that you could hook up to the outputs of the VEX -- I am not sure but I think THIS RADIO from Sparkfun.com may be something like what you'd want to use (look here for pricing) . I like this radio made by Smart Modular and sold by ZBAUSA.com, but it used RS-232 voltage levels which would require a MAX232 chip or some such to get the VEX board to communicate with it (another possible down side is that the Smart Modular radio is BTClass 2.0 -- 10m range -- while the Sparkfun one is BT Class 1 -- 100m range).

#3 You will have to get Bluetooth on your PC somehow either built in or from a UBS-Bluetooth Dongle -- very cheap -- or some other way. Once you have that set up the remote BT looks like a standard PC comm port. You will not have to manage the BT stack or any of that non-sense. It is pretty straightforward actually. Sparkfun.com has a "Bluetooth Primer" that shows how easy the BT bit is.

#4 I would get the code from Kevin Watson Kevin.org HERE
where he publishes his code to make a serial port out a standard I/O pin of the PIC chip. From what I have gathered there are some differences between the FRC and the VEX boards so you will have to port the code somewhat but they use the same micro so you should be able to muddle through pretty easily.

#5 You will have to modify the VEX default code to get messages from the serial port rather than from the Rx radios. Not too complicated I would guess because the VEX machines are supposed to be easily used in autonomous mode. This would look just like an automonomous mode only with information coming in from the serial port.

Finally, one more thing. This document and the related discussion may help you (thanks to dez250 for sharing the paper and starting the thread).

Good luck.

Joe J.