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nergiz87
Joined: 26 Apr 2010
Posts: 1
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| simple rs485 communication: rs458.c Error |
 Posted: Mon Apr 26, 2010 4:52 am |
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I need help with rs485 communication.
In my system i have master device which is rs232-rs485 converter. I found the circuit from google and the schema is like this.
My slaves will be board with pic16f877A. The tx, rx pins from pic will connect to the 1st and 4th pin of the max485. in this circuit i didn't have to control RE, DE pins via PIC which make easy to program the slave pic
but still i have problem with CCS's built in rs485.c file.
i cant include into my project. I got this error.
my code
| Code: |
#include <16F877A.h>
#include <RS485.c>
#fuses HS, NOWDT
#use delay(clock=20000000)
void main()
{
int deviceId = 0;
if(input(PIN_B1))
deviceId = 1;
if(input(PIN_B2))
deviceId = 2;
if(input(PIN_B3))
deviceId = 3;
if(input(PIN_B4))
deviceId = 4;
if(input(PIN_B5))
deviceId = 5;
#define RS485_ID deviceId
#define RS485_RX_PIN PIN_C7
#define RS485_TX_PIN PIN_C6
//defined but not using
#define RS485_ENABLE_PIN PIN_B7
#define RS485_RX_ENABLE PIN_B6
#define RS485_RX_BUFFER_SIZE 2
int8 msg[RS485_RX_BUFFER_SIZE];
rs485_init();
while(true)
{
if(rs485_get_message(msg, true))
{
if(msg[0] == deviceId)
{
//do something
}
}
//rs485_send_message(int8 to, int8 len, int8* data);
}
}
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and my second question: Am I really need this rs485.c file? In my case i didn't need control RE,DE pins.
i just want to send/rcv 2byte code from pics and receive/send 2byte from computer with acknowledgement
2byte = [1st byte: address, toggle bit] [2nd byte: command]
is it easy to do all of this with fputc(), fgetc() functions?
the rs485_init() function is too complex. there are interrups and ect. Do i need all this things? |
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Abdulla M.A.
Joined: 28 Mar 2010
Posts: 30
Location: Baghdad, Iraq
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| Posted: Thu Apr 29, 2010 10:43 am |
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Where is the posts, who removed it????
Abdulla
_________________
"A scientist can discover a new star, but he cannot make one. He would have to ask an engineer to do that."
"For an optimist the glass is half full, for a pessimist it's half empty, and for an engineer is twice bigger than necessary." |
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