hi all
there is a small machine that work with two pic's and they have communication between these two pic's
communication like
the 57a with 7 segment display and button i already do the prog for those componant
and the 72a phase control and reading tacho for speed
so the type of communication is like to send button command like start and stop from the display picto the other one to start the motor or stop
and in the other hand the pic in the power board need to send for exemble the tacho speed and other information
so the problem of this equipement is the 16c72a is short circut in vcc and gnd and the tow pic's are code protected so i try to make something like the reverse ingeniring
i m stuck on how the designer make the communication betwen thes two pics
any one help please
thank you