Notes

Experiment 9

Serial Asynchronous Communications


part1:Loop Back Test - UART

-----
ISIS:
pin25:to V.terminal(Rxd)
pin26:to V.termianl(Txd)
-------
code:
#include "ee470.h"
4 #include <ctype.h>
5 unsigned char getchu(void)
6 {
8 while(!RCIF){};
9 return(RCREG);
10 }
12 void putchu(unsigned char c)
13 {
15 while (!TXIF) {};
16 TXREG=c;
17 }
19 void main(void)
20 {
21 unsigned char c, d;
22 OSCCON=0x70;
23 ADCON1=0xF;
24 serial_init(51,1);
25 while(1) {
26 c = getchu();
27 d = toupper(c);
28 putchu(d);
29 }
30 }
############
part2:Get One Character from PC
and Echo it Back - UART

*Using the UART and the functions
available in ee445.h (getch and putch)
when you press 1---(1*)


--------
ISIS:
RA0:res=330 to led to gnd
pin25:to V.terminal(Rxd)
pin26:to V.termianl(Txd)
-------
code:
#include "ee470.h"
#include <string.h>
6 void main(void)
7 {
8 unsigned char c, k, line[40];
9 OSCCON=0x70;
10 ADCON1=0xF;
11 serial_init(51,1);
12 TRISA0=0;
13 PORTAbits.RA0=0;
14 TRISC1=1;
15 TRISC0=0;
16 PORTCbits.RC0=1;
17 strcpy(line,"Press 1 to get * followed by 1 and turn the LED ON xA xD");
18 for(k=0; k<strlen(line); k++) putch(line[k]);
19 while(1) {
20 c = getch();
21 if (c=='1')
22 {
23 PORTAbits.RA0=1;
24 putch('*');
25 }
26 else
27 RA0=0;
28 putch(c);
29 }
30 }
##############
part3:Two PICs connected Serially - UART

-----
ISIS:
system1:25 here to 26 in sys2
and 26 here to 25 in syst2
RA0 : res=330 to led to gnd
RA1 : res=330 to led to gnd
pin33:logicprobe
pin34:logicprobe

system2:25 here to 26 in sys1
and 26 here to 25 in syst1
RA0 : res=330 to led to gnd
RA1 : res=330 to led to gnd
pin33:logicprobe
pin34:logicprobe
-----
code:
there is 2codes here
code system1:
#include "ee470.h"
5 void main(void)
6 {
7 unsigned char x, c;
8 OSCCON=0x70;
9 ADCON1=0xF;
10 serial_init(51,1);
11 TRISB1=1; TRISB0=1;
12 TRISA1=0; TRISA0=0;
while(1)
15 {
17 if (bittst(PORTB,0)==0) bitclr(x,0); else bitset(x,0);
18 if (bittst(PORTB,1)==0) bitclr(x,1); else bitset(x,1);
19 putch(x);
20 c=getch();
21 // PORTA=c;
22 if (bittst(c,0)==0) bitclr(PORTA,0); else bitset(PORTA,0);
23 if (bittst(c,1)==0) bitclr(PORTA,1); else bitset(PORTA,1);
24 }
25 }


######
code system 2:
#include "ee470.h"
void main(void)
{
unsigned char x, c;
OSCCON=0x70;
ADCON1=0xF;
serial_init(51,1);
TRISB1=1; TRISB0=1;
TRISA1=0; TRISA0=0;
while(1)
{
c=getch();
if (bittst(c,0)==0) bitclr(PORTA,0); else bitset(PORTA,0);
if (bittst(c,1)==0) bitclr(PORTA,1); else bitset(PORTA,1);
if (bittst(PORTB,0)==0) bitclr(x,0); else bitset(x,0);
if (bittst(PORTB,1)==0) bitclr(x,1); else bitset(x,1);
putch(x);
}
}
####################
part4:Software to Serialize Data
and connect the PIC to PC without
UART - Software

*Without using UART, re-write
the echo program to make the
PIC communicates with the terminal
on the two wires RC0 (as Tx) and
RC1 (as Rx) at 9600bps, 1-stop, no parity.

------
ISIS:
RA0:res=330 to led to gnd
pin 15 : to V.terminal(Rxd)
pin 16: to V.termianl(Txd)
------
code:
include "ee470.h"
#include <string.h>
#define half_bit_delay __delay_us(42)
#define bit_delay __delay_us(84)
void putch_RC0(unsigned char ch)
{
int i;
PORTCbits.RC0=0;
bit_delay;
for(i=0; i<8; i++)
{
if(bittst(ch,i) == 0) PORTCbits.RC0=0; else PORTCbits.RC0=1;
bit_delay;
}
PORTCbits.RC0=1;
bit_delay;
}
unsigned char getch_RC1(void)
{
int i;
unsigned char ch;
while(PORTCbits.RC1==1);
half_bit_delay;
ch=0;
for(i=0; i<8; i++)
{
bit_delay;
if (PORTCbits.RC1==0) bitclr(ch,i); else bitset(ch,i);
}
bit_delay;
return ch;
}
void main(void)
{
unsigned char c, k, line[40];
OSCCON=0x70;
ADCON1=0xF;
TRISA0=0;
PORTAbits.RA0=0;
TRISC1=1;
TRISC0=0;
PORTCbits.RC0=1;
strcpy(line,"Press 1 to get * followed by 1 and turn the LED ON xAxD");
for(k=0; k<strlen(line); k++) putch_RC0(line[k]);
while(1) {
c = getch_RC1();
if (c=='1')
{
PORTAbits.RA0=1;
putch_RC0('*');
}
else
RA0=0;
putch_RC0(c);
}
}