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Overview The project can be used effectively to detect fast moving objects using sensors made from LED array. Explanation One of the slave microcontrollers (Slave A) is the PIC16F876A which autonomously scans the bottom row in the array with blistering speed. It is indicated by the blue LED when it is operational and the program is running. The second slave (Slave B) microcontroller has the same chip as the first, is responsible for scanning the top row of the LEDs. Although it has different slave address as Slave A, it runs the same program. The third (Master) microcontroller is a PIC18F252 that polls the slave every 100msec for an update and feeds that data to the host PC. The polling of the slave in real time by the master is indicated by the blue LED which blinks very fast. The interface uses MAX233 that is an RS232 line driver IC. It is very similar to MAX232 except that it requires no external capacitors for its voltage doubler circuit in order to save board space. The CMOS level serial data from the Master PIC is being boosted by this chip to TTL level for transmission to host PC. Rest of the story
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