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8/12/2019 lab3_c_asm
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/* Count switch pressings and display on 7-segment display. If
the PIC detects
the switch in the ON position, increment the counter and check
again after
1 second, if it is still in the ON position, wait till it goes
to the OFF
then after 0.5 seconds check for an ON condition to increment
the
counter and repeat till the counter reaches 5 then put high on
pin RA1,when it reaches 7 put low on RA1 and high on pin RA2, and
when it
reaches 8, clear the counter and turn off pin RA2.
Write the code in C language, test it on the simulator when you
are sure
that it is working properly burn it on the chip and put it in
the circuit
and verify that it is functioning correctly.
Number of key presses should be displayed on seven segment
display.
Note that Flasher.asm and Flasher1i.asm contain Delay
routines.
RB0 to RB3 of PORTB will be used to drive the 7-segment display
through 7448.
RA0 for reading the switch while RA1 and RA2 for writing to the
LEDs. */
#include "16f84a.h"#use delay (clock=4000000) // 4MHz
crystal
int1 a0, a1, a2;
int a, b;
void main()
{
set_tris_a(0x01); // pins RA0 for i/p, and RA1 and RA2 for
o/p
set_tris_b(0x00); // pins 0 to 7 of port B are outputs
b=0;
output_B(b); // clear port B
while(1)
{
if (input(pin_a0)==1) // read the switch connected to RA0
{b++; // increment b
output_B(b); // write to 7-segment display
if (b==5) output_bit(pin_a1,1); // if b=7 set RA1=1
if (b==7) {output_bit(pin_a1,0); output_bit(pin_a2,1);} // if
b=9 set RA1=0 and RA2=1
if (b==8) {output_bit(pin_a2,0); b=0; output_B(b);} // if b=11
=> RA2=0, clr counter
delay_ms(1000); // wait for 1 second
}
while (input(pin_a0)==1) {}; // wait until a0 goes down
if ((b > 0) & input(pin_a0)==0) delay_ms(500); // now RA0
is off, wait for 0.5 second
}
}
Figure 1: Connect RB3, RB2, RB1, RB0 to pins 6, 2, 1, 7 of 7448
BCD to 7-segment display driver, then pins 9,10, 11, 12, 13, 15, 14
of 7448 to pins 1, 2, 3, 4, 5, 6, 7 (a, b, c, d, e, f, g) of the
common cathode 7-segment display.Connect 470 between pin 8 of the
display and the ground
1
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8/12/2019 lab3_c_asm
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; Lab3-retlw.ASM for 16F84.
; read RA3...RA0 and display on PORTB ... to Common cathode 7seg
dispaly
; Usage of PIC 16F84 instructions.
;*********************************************************
#include "p16f84.inc"; EQUATES SECTION
num equ 0x0c ;b=NUMBER to be displayed on 7seg
;*********************************************************
LIST P=16F84 ; we are using the 16F84.
ORG 0 ; org address in memory is 0
GOTO START ; goto start of program (jump over subroutines)
;**********************************************************************
; Configuration Bits
__CONFIG _CP_OFF & _WDT_OFF & _PWRTE_ON & _XT_OSC
;H3FF1
;*********************************************************
;SETUP SECTION
START: BSF STATUS,RP0 ;Turns to Bank1.
MOVLW B00001111; bit 0 TO 3 of PORTA as I/P
MOVWF TRISAMOVLW B00000000
MOVWF TRISB ;PORTB as OUTPUT
;
BCF STATUS,RP0 ;Return to Bank0.
CLRF PORTB ;Clears PortB.
;*********************************************************
;Program starts now.
;ADD NUMBERS FROM LOCATION TABLE AND STORE
;THE RESULT IN PORTB. USE INDIRECT ADDRESSING FOR READING.
BEGIN: movf PORTA,W ; W
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8/12/2019 lab3_c_asm
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Interface without 7448 BCD to 7segment driver
/* Lab3.c
Count switch pressings and drectly display on 7-segment
display-Common cathode.
If the PIC detects
the switch in the ON position, increment the counter and check
again after
0.5 second, if it is still in the ON position, wait till it goes
to the OFF
then after 0.5 seconds check for an ON condition to increment
the
counter and repeat till the counter reaches 5 then put high on
pin RA1,
when it reaches 7 put low on RA1 and high on pin RA2, and when
it
reaches 14 (=0xE), clear the counter and turn off pin RA2.
Write the code in C language, test it on the simulator when you
are sure
that it is working properly burn it on the chip and put it in
the circuit
and verify that it is functioning correctly.
Number of key presses should be displayed on seven segment
display.
Note that Flasher.asm and Flasher1i.asm contain Delay
routines.
RB0 to RB6 (7-segment) of PORTB will be used to drive the
7-segment display directly.RA0 for reading the switch while RA1 and
RA2 for writing to the LEDs.
*/
#include "16f84a.h"
#use delay (clock=4000000) // 4MHz crystal
int b;
int
map[16]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,
0b01110111, 0b01111100, 0b01011000, 0b01011110, 0b01111001,
0b01110001}; // 0..0xF
void main()
{
set_tris_a(0x11); // pins RA0 for o/p, and RA1 and RA22 for
o/p
set_tris_b(0x00); // pins 0 to 7 of port B are outputs
b=0;
output_B(map[b]); // clear port B
while(1)
{
if (input(pin_a0)==1) // read the switch connected to RA0
{
b++;
output_B(map[b]); // write to 7-segment display
if (b==5) output_bit(pin_a1,1); // if b=7 set RA1=1
if (b==7) {output_bit(pin_a1,0); output_bit(pin_a2,1);} // if
b=9 set RA1=0 and RA2=1
if (b==0xe) {output_bit(pin_a2,0); b=0; output_B(map[b]);}
delay_us(1); // wait for 1u second-Oshon simulator and 500m sec
fo hardware
}while (input(pin_a0)==1) {}; // wait until a0 goes down
if ((b > 0) & input(pin_a0)==0) delay_us(1); // now RA0
is off, wait for 0.5 second
}
}
and in Assembly language
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