como les va e estado buscando en la web y en el foro y encontre este ejemplito en CCS C par trabajar con el RS-485 a ver si alguien me lo puede
explicar que no lo entiendo muy bien
#include <16F628A.h>
#device *=16
#fuses HS, NOWDT, NOLVP, NOBROWNOUT, NOPROTECT, PUT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_B2, rcv=PIN_B1, stream=PC)
#define RS485_RX_BUFFER_SIZE 64
#define RS485_USE_EXT_INT TRUE
int8 OUR_RS485_ID = 0;
#define RS485_ID OUR_RS485_ID
#include <rs485.c>
#include <stdlib.h>
int8 in_char = 0;
int8 next_in = 0;
int8 next_out = 0;
int8 msg[64];
#INT_RDA
void serial_isr()
{
in_char = fgetc(PC);
}
#INT_TIMER1
void timer1_isr()
{
int8 i;
if(rs485_get_message(msg, FALSE))
{
printf("\n\r%d: ", msg[0]);
for(i=0; i < msg[1]; ++i)
putc(msg[i+2]);
printf("\n\r");
}
}
void RS485send(char* s, int8 id)
{
int8 size;
for(size=0; s[size]!='\0'; ++size);
rs485_wait_for_bus(FALSE);
while(!rs485_send_message(id, size, s))
delay_ms(OUR_RS485_ID);
}
char PCgetc()
{
in_char = 0;
while(!in_char);
return in_char;
}
int8 PCgetInt()
{
int8 i, s[3];
for(i=0; (s[i]=PCgetc()) != '\r' && i<3; ++i);
return atoi(s);
}
char* PCgetMsg()
{
int8 i;
for(i=0; (msg[i] = PCgetc()) != '\r' && i<64; ++i);
msg[i] = '\0';
return &(msg[0]);
}
void main()
{
int8 i, send_addr = 0;
char command;
setup_timer_1(T1_INTERNAL | T1_DIV_BY_1);
enable_interrupts(INT_RDA);
enable_interrupts(GLOBAL);
rs485_init();
while(OUR_RS485_ID == 0 || OUR_RS485_ID >= 255)
{
printf("Please choose a network ID (1-255): ");
OUR_RS485_ID = PCgetInt();
}
printf("\n\rYour ID is: %d\n\r\n\rIf you require assistance, press h.\n\r", OUR_RS485_ID);
while(command != 'Q')
{
enable_interrupts(INT_TIMER1);
command = toupper(PCgetc());
disable_interrupts(INT_TIMER1);
switch(command)
{
case 'S':
if(send_addr == 0 || send_addr > 255)
{
printf("\n\r\n\rEnter send address (1-255): ");
send_addr = PCgetInt();
}
printf("\n\r%d:>", send_addr);
RS485send(PCgetMsg(), send_addr);
printf("\n\r");
break;
case 'C':
send_addr = 0;
while(send_addr == 0 || send_addr > 255)
{
printf("\n\r\n\rEnter send address (1-255): ");
send_addr = PCgetInt();
printf("\n\r");
}
break;
case 'I':
OUR_RS485_ID = 0;
while(OUR_RS485_ID == 0 || OUR_RS485_ID >= 255)
{
printf("\n\rPlease choose a network ID (1-255): ");
OUR_RS485_ID = PCgetInt();
}
printf("\n\rYour ID is: %d\n\r\n\r", OUR_RS485_ID);
break;
case 'H':
printf("\n\rCommands: (S)end message, (C)hange Send Address, ");
printf("Change (I)D, (H)elp, (Q)uit.\n\r");
break;
default:
if(command != 'Q')
printf("\n\rInvalid command!\n\r");
}
}
}
muchas gracias de ante mano espero me puedan ayudar
