EX_SQW.C
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/////////////////////////////////////////////////////////////////////////
//// EX_SQW.C ////
//// ////
//// This program displays a message over the RS-232 and waits for ////
//// any keypress to continue. The program will then begin a 1khz ////
//// square wave over I/O pin B0. ////
//// ////
//// Comment out the printf's and getc to eliminate the RS232 and ////
//// just output a square wave. ////
//// ////
//// Change both delay_us to delay_ms to make the frequency 1 hz. ////
//// This will be more visable on a LED. ////
//// ////
//// Configure the CCS prototype card as follows: ////
//// Insert jumpers from 42 to 47. ////
//// See additional connections below. ////
//// ////
//// This example will work with the PCB, PCM and PCH compilers. ////
//// The following conditional compilation lines are used to ////
//// include a valid device for each compiler. Change the device, ////
//// clock and RS232 pins for your hardware if needed. ////
/////////////////////////////////////////////////////////////////////////
//// (C) Copyright 1996,2001 Custom Computer Services ////
//// This source code may only be used by licensed users of the CCS ////
//// C compiler. This source code may only be distributed to other ////
//// licensed users of the CCS C compiler. No other use, ////
//// reproduction or distribution is permitted without written ////
//// permission. Derivative programs created using this software ////
//// in object code form are not restricted in any way. ////
/////////////////////////////////////////////////////////////////////////
#if defined(__PCM__)
#include <16c74.h>
#fuses HS,NOWDT,NOPROTECT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7) // Jumpers: 8 to 11, 7 to 1
#elif defined(__PCB__)
#include <16c56.h>
#fuses HS,NOWDT,NOPROTECT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_A3, rcv=PIN_A2) // Jumpers: 11 to 17, 12 to 18
#elif defined(__PCH__)
#include <18c452.h>
#fuses HS,NOPROTECT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7) // Jumpers: 8 to 11, 7 to 12
#endif
main() {
printf("Press any key to begin\n\r");
getc();
printf("1 khz signal activated\n\r");
while (TRUE) {
output_high(PIN_B0);
delay_us(500);
output_low(PIN_B0);
delay_us(500);
}
}
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