'--------------Title--------------- ' File......16F877A_railroad.pbp ' Started....6/1/05 ' Microcontroller used: Microchip Technology 16F877A ' microchip.com ' PicBasic Pro Code, micro-Engineering Labs, Inc. ' melabs.com '--------Program Desciption-------- ' Two LED's flash like railroad crossing. '-------------Schematic------------ ' See schematic at: ' http://www.cornerstonerobotics.org/schematics/pic16f877a_railroad.pdf '----------Related Lesson---------- ' railroad.pbp (the 16F88 program) is used in the lesson ' INTRODUCTION TO PROGRAMMING 1 at: ' http://www.cornerstonerobotics.org/curriculum/lessons_year2/erii11_pic_introduction_programming1.pdf '---------Revision History--------- ' 11/17/08 Update to PIC16F88 and ' add 16F88 oscillator initialization ' 1/1/09 Change PIC16F88 to PIC16F877A '----------Initialization---------- TRISB = %11111100 ' Sets up pins RB0 & RB1 of PORTB as outputs ' and pins RB2-RB7 of PORTB as inputs '-------------Main Code------------ start: High 0 ' Makes pin RB0 output HIGH(5 volts) Low 1 ' Makes pin RB1 output LOW(0 volts) Pause 500 ' Pause 500 milliseconds (1/2 seconds) with LED on Low 0 ' Makes pin RB0 output LOW 0 volts) High 1 ' Makes pin RB1 output High(5 volts) Pause 500 ' Pause 500 milliseconds (1/2 seconds)with LED on GoTo start ' Jump to loop label and start all over again End