multiprocessing using 89c52 microcontroller

hi
well i hav to design a priority based intercom system using microcontroller.....

task is basically that call will be made from one station to another station by pressing a single button...let suppose a button is pressed from station 1 then the signal should be shown on the station 2 which hav been called and m using a blinking LED for indication..this what iz indication side..but now call will i only established when the station 2 will also press the respective button.....if station 2 doesnot press button means LED should be keep on blinking.

now microcontroller iz buzy for blinking loop...let if station 3 pressed button for station 4 same indication signal should go on station 4 n LED should blink...but as microcontroller iz buzy in blinking of first case than how to solve this up.....

is it possible that mmicro controller keep on blinking LED n simultaneously start to operate an other LED,.....

i hav a technique to use two microcontroller one slave n one master slave should scan button pass signal serially to master microcontroller n then master should give signal for LED blinking n switching


plz reply me with solution....
thanks for ur cooperation

You can set a free-run counter to generate a periodically interrupt(about 0.5sec). Each time it enters the interrupt routine it changes the state of the led (blinks). Apart from the interrupt routine, your cpu is completely free to run other task all the time.

Or use an OS.
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Amr