Builders guide robot pacman.pdf

Obstacle SensorsPowerPIC16F877MicrocontrollerLeft ObstacleSensorRight ObstacleSensorFront ObstacleSensorFigure 32. Model of interface between PIC and obstacle sensors6.1.2 LCD DisplayThe PIC sends three types of signals to the LCD depending on the event.In the case of a Ghost contact, the PIC sends an LCD lives signalindicating the number of times it has been hit. When Pac-Man runs over amaze dot, it sends an LCD point signal indicating the number of dots it hascollected. Finally, an LCD reset signal is for initializing the display whena new game begins.LCD displayPIC16F877MicrocontrollerFigure 33. Model of interface between PIC and LCD display6.1.3 RF ReceiverThe RF receiver interfaces with the PIC’s interrupt service routine becausethe user can press any button on the controller at any point in the game.This scenario was chosen because it was vital that the PIC did not missany of the control signals, which may have resulted if the RF signals werereceived through polling.Three bits are used to communicate the four different directions. Theformat is listed below.26