[Cuog]

you could also use an analog in/ out system, its much simpler but i do not know what the BASIC stamps can do, i have had very little experience with them,

Basically each robot has a cable connecting ones ana_out to the others ana_in port and that gives a large number of comands that can be sent and decoded with an if statement block or if basic allows it a case block

each one will send a signal to the other and decode the signal as it comes in via each one of their input and output tetherings, however if you get alot or robots out there this gets very complicated and messy, I would not use more than 3 robots at a time with this