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longmenok
Joined: 23 Oct 2006
Posts: 12
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| CAN Problem? How to work 18F2431 +mcp2515 |
 Posted: Tue Jun 19, 2007 10:36 am |
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Hello! I have a work about CAN communication.
The following is my code. If it were used for 16F877A, it are good!
But it arenot work for 18F2431
I want to know how to correct it.
Thanks ，say sorry to my poor english.
osc=20M mcp2515 20M CAN bitrate =500K
2431 -----> 2515
PIN_C6(17) ----->> CS(16)
PIN_C7(18) ----->> SI(14)
PIN_C4(15) ----->> SO(15)
PIN_C5(16)----->> SCK(13)
PIN_C3(14) ----->> INT(12)
transmit code
| Code: |
#include <18F2431.h>
#fuses HS,NOPROTECT,NOLVP,NOWDT
#use delay(clock=20000000)
#include "MCP2515.c"
//////////////////////////////////////////////////////////////////////////
// main code //
//////////////////////////////////////////////////////////////////////////
void main()
{
unsigned char buffer[2]={0x19,0x82};
output_low(PIN_C1);
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_spi(FALSE);
can_init();
while(TRUE)
{
if(can_tbe())
{
can_putd(0x201,&buffer[0],2,3,0,0);
// receive ID 201 is good.
delay_ms(900);
output_high(PIN_C1); //led on
delay_ms(100);
output_low(PIN_C1); //led off
}
}
}
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"MCP2515.c"
| Code: |
#ifndef EXT_CAN_CS
//18F2341
#define EXT_CAN_CS PIN_C6
#define EXT_CAN_SI PIN_C7
#define EXT_CAN_SO PIN_C4
#define EXT_CAN_SCK PIN_C5
... ... ... ... ... ... ... ... ... ... ... ...
void can_set_baud(void) {
struct struct_CNF1 new_CNF1;
struct struct_CNF2 new_CNF2;
struct struct_CNF3 new_CNF3;
//use MBtime setup CAN Bitrate osc=20M bitrate=500k
new_CNF1=0x00;
new_CNF2=0xBA;
new_CNF3=0x07;
... ... ... ... ... ... ... ... ... ... ... ...
//other codes are the same as can-mcp251x.c
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MBTIME Download
http://www.intrepidcs.com/index.php?name=CmodsDownload&file=index&req=viewdownload&cid=2&orderby=dateD |
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longmenok
Joined: 23 Oct 2006
Posts: 12
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| Posted: Mon Jun 25, 2007 9:30 am |
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| help |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Jun 25, 2007 11:26 am |
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| Quote: |
The following is my code. If it were used for 16F877A, it are good!
But it are not work for 18F2431. |
Does the only difference between the two programs consist
of the #include file line ? Other than that, are the two programs
completely identical ?
| Code: |
#include <18F2431.h>
or
#include <16F877A.h>
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Are the hardware connections between the PIC and the MCP2515
the same, for the 18F2431 and the 16F877A ?
Is the MCP2515 circuit the same, for each PIC ?
Does the MCP2515 have a 20 MHz crystal in each case ?
In other words, you said it works for 16F877A, but I want to get
a confirmation from you that the only thing you changed for the
new project is the PIC, and the #include statement.
Also, post the CCS compiler version that you used with each PIC. |
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longmenok
Joined: 23 Oct 2006
Posts: 12
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| Posted: Sun Jul 08, 2007 9:53 pm |
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MCP2515 is used. can-mcp2510.c is modified as following.
MCP2515 have a 20 MHz crystal in each case
can-mcp2510.c connect with 16F877A is following
| Code: |
//877A IO pins connected to MCP2515
#ifndef EXT_CAN_CS
#define EXT_CAN_CS PIN_A5
#define EXT_CAN_SI PIN_C5
#define EXT_CAN_SO PIN_C4
#define EXT_CAN_SCK PIN_C3
// mcp2515's PIN INT connect with 877A's RB0
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set_baud
| Code: |
void can_set_baud(void) {
struct struct_CNF1 new_CNF1;
struct struct_CNF2 new_CNF2;
struct struct_CNF3 new_CNF3;
new_CNF1=0x00;
new_CNF2=0xBA;
new_CNF3=0x07;
MCP2515_write(CNF1, (int)new_CNF1);
MCP2515_write(CNF2, (int)new_CNF2);
MCP2515_write(CNF3, (int)new_CNF3);
}
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can-mcp2510.c connect with 18F2431 is following
| Code: |
//18F2431 IO pins connected to MCP2515
#ifndef EXT_CAN_CS
//2341
#define EXT_CAN_CS PIN_C6 //SS
#define EXT_CAN_SI PIN_C7 //SDO
#define EXT_CAN_SO PIN_C4 //SDI//SDA
#define EXT_CAN_SCK PIN_C5 //sck/scl
//mcp2515' PIN INT connect with 2431's RC3
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the above is the difference for their connect
18F2431'baud is the same as 16F877A
the following is code for 16F877A and 18F2431 to transmat
| Code: |
#include <16F877A.h>
#fuses HS,NOPROTECT,NOLVP,NOWDT
#use delay(clock=20000000)
#include "can-mcp2510.c"
//////////////////////////////////////////////////////////////////////////
// main code //
//////////////////////////////////////////////////////////////////////////
void main()
{
unsigned char buffer[2]={0x19,0x82};
output_low(PIN_C1);
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
can_init();
while(TRUE)
{
if(can_tbe())
{
can_putd(0x722,&buffer[0],2,3,0,0);
delay_ms(900);
output_high(PIN_C1);
delay_ms(100);
output_low(PIN_C1);
}
}
}
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| Code: |
#include <18F2431.h>
#fuses HS,NOPROTECT,NOLVP,NOWDT
#use delay(clock=20000000)
#include "can-mcp2510.c"
//////////////////////////////////////////////////////////////////////////
// main code //
//////////////////////////////////////////////////////////////////////////
void main()
{
unsigned char buffer[2]={0x19,0x82};
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_spi(FALSE);
can_init();
while(TRUE)
{
if(can_tbe())
{
can_putd(0x722,&buffer[0],2,3,0,0);
}
}
}
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the following is code for 18F458 to receive //correct it
| Code: |
#include <18F458.h>
#fuses HS,NOPROTECT,NOLVP,NOWDT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#include "can-18xxx8.c"
// set baud in Ccan-18xxx8.c
// BRGCON1 = 0x00;
// BRGCON2 = 0xBA;
// BRGCON3 = 0x07;
///////////////////////////////////////////////////////////////////////
/// main code //////
///////////////////////////////////////////////////////////////////////
void main(void)
{
struct rx_stat rxstat;
int32 rx_id;
unsigned char buffer[2];
unsigned char rx_len;
output_low(PIN_D1);
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
can_init();
while(TRUE)
{
if(can_kbhit())
{
if(can_getd(rx_id,&buffer[0],rx_len, rxstat))
{
if((rx_id==0x722)&&(buffer[0]==0x19)&&(buffer[1]==0x82))
{
output_high(PIN_D1);
delay_ms(100);
output_low(PIN_D1);
}
}
}
}
}
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Thanks! PCM programmer
Last edited by longmenok on Thu Jul 12, 2007 1:14 am; edited 3 times in total |
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longmenok
Joined: 23 Oct 2006
Posts: 12
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| Posted: Tue Jul 10, 2007 7:38 pm |
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| Can you help me！ Thanks！ |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Jul 11, 2007 11:57 am |
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| Quote: |
The following is code for 16F877A and 18F2431 to receive:
#include <18F458.h>
#fuses HS,NOPROTECT,NOLVP,NOWDT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#include "can-18xxx8.c"
// set baud in Ccan-18xxx8.c
// BRGCON1 = 0x00;
// BRGCON2 = 0xBA;
// BRGCON3 = 0x07;
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The can-18xxx8.c file only works with 18F chips that have a built-in
CAN module. The 16F877A and 18F2431 do not have one.
This code will not work with those two PICs. |
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longmenok
Joined: 23 Oct 2006
Posts: 12
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| Posted: Thu Jul 12, 2007 1:10 am |
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I use 18F2431+mcp2515 to transmit motor QEI data, and use 18F458 to receive data. when I use 16F877A+mcp2515, CAN Communication can good work. However I use 18F2431+mcp2515 , 18F458 can't receive any data.
IN transmit code use "can-mcp2510.c" for 18f2431
and in receive code use "can-18xxx8.c" for 18f458
their bauds are same,
| Code: |
Transmit by 18F2431
void can_set_baud(void) {
struct struct_CNF1 new_CNF1;
struct struct_CNF2 new_CNF2;
struct struct_CNF3 new_CNF3;
new_CNF1=0x00; //Set baud
new_CNF2=0xBA;
new_CNF3=0x07;
MCP2515_write(CNF1, (int)new_CNF1);
MCP2515_write(CNF2, (int)new_CNF2);
MCP2515_write(CNF3, (int)new_CNF3);
}
Receive by 18F458
// BRGCON1 = 0x00; set baud
// BRGCON2 = 0xBA;
// BRGCON3 = 0x07;
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why 18F2431 can't communiate?
Thanks! PCM programmer. |
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longmenok
Joined: 23 Oct 2006
Posts: 12
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| Posted: Thu Jul 12, 2007 2:01 am |
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I test it, can_init() can't good work.
In can_mcp2510.c
| Code: | void can_set_mode(CAN_OP_MODE mode) {
struct struct_CANCTRL old_CANCTRL;
old_CANCTRL=MCP2515_read(CANCTRL);
old_CANCTRL.reqop=mode;
MCP2515_write(CANCTRL, (int)old_CANCTRL);
do {
old_CANCTRL=MCP2515_read(CANCTRL); // In there, it is always LOOP
} while (old_CANCTRL.reqop != mode);
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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