Greetings PIClisters!

I am planning to start building a six-legged robot walker during the
summer this year.. mainly to do some experimenting with subsumption
architecture. I recently bought "Mobile Robots".. a really excellent
book. I was thinking of applying the basic 'rug warrior' concept to a
walker, using 3 PIC16C84's (2 legs=4 RCservos to a PIC) and a 68HC11
main controller (well, there isn't really a main controller as such
since all the "behaviours" run in parallel anyway). I'm quite keen on
using interactive C for the 68hc11, and allowing the processors to talk
via a simple tx/rx serial bus with some kind of addressing/conflict
avoidance system (still to be figured out properly).
Has anyone had any experience with this kind of thing? Any hints on
doing small amounts of preemptive multitasking on a 16C84? (-don't
laugh!) I'd like to get the PICs basically controlling the servos,
generating the required pulses (pity the '84 doesn't have the
input/output capture facilities of the 68hc11) and running a couple of
AFSMs that allow the robot to balance and walk. The 68hc11 would handle
data from the sensors and run the coupled 'sensory' behaviours (eg.
avoid wall, follow light, hide etc.) in parallel, sending commands to
the walk AFSMs on the PICs. Any hints/suggestions on any of this?

In time I'll hack into the servos to get at the 'error' voltage so that
I can integrate some kind of force feedback into the system (may have to
add another PIC to handle this.. but that's the beauty of subsumption I
guess; just plug in another processor!)

Any suggestions/complaints etc. about any of the above would be greatly
appreciated. Especially stuff on the multiprocessor-programming front!
Thanks
-Dave
(david.howey@shades.nildram.co.uk)
 * RM 1.2  * Eval Day 527 * "Do not adjust your mind, there is a fault in reali
y..."