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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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 Posted: Wed Sep 23, 2009 6:13 pm |
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I built the circuits, compiled it with PCH vs. 4.099, and it all works
perfectly. I modified my two PicDem2-Plus boards to add sockets
for MCP2551 chips (with 120 ohm termination resistors). I have a
3-pin, 12 inch (30.5 cm) cable connected between the two boards
with wires for CANH, CANL, and GND. I have the Rs pin on each
MCP2551 connected to ground. The Vref pin is unconnected.
To test it, I started up a terminal program such as TeraTerm and typed in
some text (random asdf, followed by Hello There). It all works.
| Quote: | | asdfasdfadsffas Hello there |
Here's the code. This is the same as in the original post,
http://www.ccsinfo.com/forum/viewtopic.php?t=29627&start=6
except that the #include for the driver was changed to can-18F4580.c
because we are using the 18F2580, which is part of the 18F4580 family.
| Code: |
#include <18F2580.h>
#fuses HS, NOPROTECT, PUT, BROWNOUT, NOWDT, NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
#include <can-18F4580.c> // Use correct driver
#define BOARD1_ID 24
#define BOARD2_ID 25
// Uncomment this line to compile code for Board #1.
// Comment it out to compile for Board #2.
#define BOARD1 1
//======================================
void main()
{
struct rx_stat rxstat;
int32 rx_id;
int32 tx_id;
int8 rx_len;
int8 buffer[8];
can_init();
#ifdef BOARD1 // For Board #1
while(1)
{
buffer[0] = getc(); // Wait for a character
// Transmit it to board #2.
can_putd(BOARD2_ID, buffer, 1, 1, 1, 0);
buffer[0] = 0; // Clear the buffer byte
// Wait for the char to be echoed back.
while(!can_kbhit());
if(can_getd(rx_id, buffer, rx_len, rxstat))
{
if(rx_id == BOARD1_ID) // Is it for this board ?
{
putc(buffer[0]); // If so, display the char
}
}
}
#else // For Board #2
while(1)
{
if(can_kbhit()) // Message available ?
{
// If so, get the message.
if(can_getd(rx_id, buffer, rx_len, rxstat))
{
if(rx_id == BOARD2_ID) // Is it for this board ?
{
// If so, echo back the character.
can_putd(BOARD1_ID, buffer, 1, 1, 1, 0);
}
}
}
}
#endif
}
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My advice is:
1. Check your connections. Make sure there is a ground wire between
the two boards.
2. Make sure that you really are compiling two versions of the code,
one for Board #1 and another for Board #2. To compile for #1,
you use this line:
To compile for #2, you use this line:
| Quote: | | // #define BOARD1 1 |
Note that it's commented out for #2. The #define is not changed in any
way, except that it's commented out. It's not changed to '2', or 'FALSE'
or anything like that.
3. Final suggestion: Do it exactly like this, with the RS-232 terminal
for input and output. Don't use a debugger. Don't use a simulator.
Don't single-step through it or use breakpoints. Just run it. |
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halibatsuiba
Joined: 12 Aug 2009
Posts: 30
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| Posted: Wed Sep 23, 2009 8:24 pm |
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| PCM programmer wrote: |
My advice is:
1. Check your connections. Make sure there is a ground wire between
the two boards.
2. Make sure that you really are compiling two versions of the code,
one for Board #1 and another for Board #2. To compile for #1,
you use this line:
To compile for #2, you use this line:
| Quote: | | // #define BOARD1 1 |
Note that it's commented out for #2. The #define is not changed in any
way, except that it's commented out. It's not changed to '2', or 'FALSE'
or anything like that.
3. Final suggestion: Do it exactly like this, with the RS-232 terminal
for input and output. Don't use a debugger. Don't use a simulator.
Don't single-step through it or use breakpoints. Just run it. |
1: Check
2: Check
3: Heh... I just realized I don't have serial port in any of my PCs(laptops). I guess I need to buy some kind of adapter for that.
In the meanwhile:
If I change the board #1 program slightly
| Code: | | buffer[0] = getc(); // Wait for a character |
Changed to
| Code: | delay_ms(1000);
buffer[0] = 'x'; |
and
| Code: | | putc(buffer[0]); // If so, display the char |
changed to
| Code: | | printf("%c",buffer[0]); |
With those changes board #1 sends character 'x' once a second and if board #2 responds, prints reply to serial LCD.
This should work too, right? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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halibatsuiba
Joined: 12 Aug 2009
Posts: 30
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| Posted: Thu Sep 24, 2009 8:43 am |
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I tested this with USB-serial-adapter I found behind my mythtv-box. 
If I test with both boards: nothing
If I put board#1 to loopback mode: nothing.
If I modify board#1 code so that it sends character to serial TX every time it receives character to serial RX, I get characters to terminal screen --> connection between PC and PIC works.
PCM: Can you post the schematics of your test circuit?  |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Thu Sep 24, 2009 2:06 pm |
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| Quote: |
Can you post the schematics of your test circuit?
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It's the same as your schematic, except that I don't use a resistor on
the Rs pins. They are connected to ground. |
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halibatsuiba
Joined: 12 Aug 2009
Posts: 30
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| Posted: Thu Sep 24, 2009 10:12 pm |
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| PCM programmer wrote: |
It's the same as your schematic, except that I don't use a resistor on
the Rs pins. They are connected to ground. |
So now our circuits are identical.
There must be something wrong in board#1 because loopback did not work.
I switched boards and now loopback works. Sort of.
Terminal (PC) sends character 'a' (0x61) to board, board sees it as 'O' (0x4F) and sends it to CAN loopback where putc-function sends it back to PC.
PC shows character 'X' (0x58).
PC terminal sw is using 9600 8N1, as well is Pic.
Can someone explain this to me?
I will build yet another board tomorrow and continue with it.
Edit: I just built a null-modem cable and verified connection between two PCs. Works just fine, all sent characters are received as expected.
Problem is not in PC side. Interesting.
Edit2:
When using just this simple loop:
| Code: | while(1)
{
buffer[0] = getc(); // Wait for a character
putc(buffer[0]);
} |
Sending 'a' from PC terminal produces 'X' to terminal.
Usually this kind of behaviour is caused by baudrate mismatch between devices but I don't think it is the case this time. I tested changing baudrates in terminal side and in PIC-side. No effect.
Definition in 18F2580.c line 105 says:
| Code: | | #use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7) |
Baudrate is 9600 and I suppose other parameters are 8-N-1 if they are not defined there? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Sep 25, 2009 12:08 pm |
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| Quote: | When using just this simple loop:
while(1)
{
buffer[0] = getc(); // Wait for a character
putc(buffer[0]);
}
Sending 'a' from PC terminal produces 'X' to terminal. |
Post your complete test program, which has the code shown above in it.
Post the compiler version that you are using.
Post a description of your RS232 hardware on your board.
i.e., Are you using a Max232A or similar type of chip ? |
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halibatsuiba
Joined: 12 Aug 2009
Posts: 30
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| Posted: Sun Sep 27, 2009 8:59 pm |
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| PCM programmer wrote: |
Post your complete test program, which has the code shown above in it.
Post the compiler version that you are using.
Post a description of your RS232 hardware on your board.
i.e., Are you using a Max232A or similar type of chip ? |
It is your test code with this modification:
| Code: |
#include <18F2580.h>
#fuses HS, NOPROTECT, PUT, BROWNOUT, NOWDT, NOLVP
#use delay(clock=20000000)
//#use rs232(baud=115200,xmit=PIN_C6, rcv=PIN_C7,ERRORS)
#include <can-18F4580.c> // Use correct driver
#define BOARD1_ID 24
#define BOARD2_ID 25
// Uncomment this line to compile code for Board #1.
// Comment it out to compile for Board #2.
#define BOARD1 1
//======================================
void main()
{
struct rx_stat rxstat;
int32 rx_id;
int32 tx_id;
int8 rx_len;
int8 buffer[8];
can_init();
//can_set_mode(CAN_OP_LOOPBACK);
printf("Starttaillaan...");
#ifdef BOARD1 // For Board #1
while(1)
{
buffer[0] = getc(); // Wait for a character
putc(buffer[0]);
}/*
// Transmit it to board #2.
can_putd(BOARD2_ID, buffer, 1, 1, 1, 0);
buffer[0] = 0; // Clear the buffer byte
// Wait for the char to be echoed back.
while(!can_kbhit());
if(can_getd(rx_id, buffer, rx_len, rxstat))
{
if(rx_id == BOARD1_ID) // Is it for this board ?
{
putc(buffer[0]); // If so, display the char
}
}
}*/
#else // For Board #2
while(1)
{
if(can_kbhit()) // Message available ?
{
// If so, get the message.
if(can_getd(rx_id, buffer, rx_len, rxstat))
{
if(rx_id == BOARD2_ID) // Is it for this board ?
{
// If so, echo back the character.
can_putd(BOARD1_ID, buffer, 1, 1, 1, 0);
}
}
}
}
#endif
}
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Compiler version:
| halibatsuiba wrote: |
Allright. Now I have PCH version 4.099 but... |
Circuit is the same what you have, and now I have Rs tied to ground too.
| PCM programmer wrote: |
It's the same as your schematic, except that I don't use a resistor on
the Rs pins. They are connected to ground. |
About RS232 hw: I replaced MAX232 in my circuit and now code above echoes everything back properly. Looks like I had defective MAX232.
If I set Board #1 to loopback mode, everything is echoed back to terminal as well.
Still nothing if I try to communicate with board #2 over CAN.
I rebuilt board #2 with all new components.
Debugging continues... |
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halibatsuiba
Joined: 12 Aug 2009
Posts: 30
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| Posted: Sun Sep 27, 2009 10:10 pm |
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| halibatsuiba wrote: |
Debugging continues... |
Whadda'y'know...
I could not think of anything else to try so I built another board #2 to a brand new breadboard and...
It works!
I can send characters from terminal over RS232 to board #1, board #1 sends them over CAN bus to board #2 who, in turn, echoes them back to terminal via board #1.
[With voice of TV commercial]: "It works, It really works!"
Looks like there is two rows shorted in my old trusted currently-in-the-trashcan breadboard! 
Thank you, PCM, very much for your help in this issue. |
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ivrj
Joined: 17 Mar 2009
Posts: 7
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| Posted: Wed Oct 14, 2009 4:29 pm |
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I am also having the same problem.
My board #1 stops on:
| Quote: | | while(!can_kbhit()); |
I've modified the source to be easy to debug:
| Code: |
#include <18F2580.h>
#fuses HS, NOPROTECT, PUT, BROWNOUT, NOWDT, NOLVP
#use delay(clock=4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
#include <can-18F4580.c> // Use correct driver
#define BOARD1_ID 24
#define BOARD2_ID 25
// Uncomment this line to compile code for Board #1.
// Comment it out to compile for Board #2.
//#define BOARD1 1
//======================================
void main()
{
struct rx_stat rxstat;
int32 rx_id;
int32 tx_id;
int8 rx_len,i;
int8 buffer[8];
can_init();
// starting
for(i = 0; i < 13; i++)
{
output_toggle(pin_a1);
delay_ms(90);
output_toggle(pin_a0);
output_toggle(pin_a1);
delay_ms(90);
output_toggle(pin_a0);
}
output_low(pin_a0);
output_low(pin_a1);
delay_ms(400);
#ifdef BOARD1 // For Board #1
while(1)
{
printf("Press a key\r");
output_high(pin_a0);
buffer[0] = getc(); // Wait for a character
printf("lido:%s ", buffer[0]);
output_low(pin_a0);
// Transmit it to board #2.
if(can_putd(BOARD2_ID, buffer, 1, 1, 1, 0))
{
printf("Sending a msg\r");
for(i = 0; i < 6; i++)
{
output_toggle(pin_a0);
delay_ms(100);
}
output_low(pin_a0);
}
else
{
printf("Msg sending fail\r");
for(i = 0; i < 15; i++)
{
output_toggle(pin_a0);
delay_ms(50);
output_low(pin_a0);
}
}
buffer[0] = 0; // Clear the buffer byte
// Wait for the char to be echoed back.
while(!can_kbhit());
if(can_getd(rx_id, buffer, rx_len, rxstat))
{
printf("msg received\r");
for(i = 0; i < 10; i++)
{
output_toggle(pin_a1);
delay_ms(50);
}
output_low(pin_a1);
if(rx_id == BOARD1_ID) // Is it for this board ?
{
for(i = 0; i < 15; i++)
{
output_toggle(pin_a1);
delay_ms(50);
}
output_low(pin_a1);
printf("msg:" );
putc(buffer[0]); // If so, display the char
}
}
}
#else // For Board #2
while(1)
{
if(can_kbhit()) // Message available ?
{
for(i = 0; i < 6; i++) // blink a received led
{
output_toggle(pin_a0);
delay_ms(100);
}
output_low(pin_a0);
// If so, get the message.
if(can_getd(rx_id, buffer, rx_len, rxstat))
{
if(rx_id == BOARD2_ID) // Is it for this board ?
{
for(i = 0; i < 14; i++) // blink a received led
{
output_toggle(pin_a0);
delay_ms(50);
}
output_low(pin_a0);
// If so, echo back the character.
can_putd(BOARD1_ID, buffer, 1, 1, 1, 0);
}
}
}
}
#endif
} |
I just changed the oscilator from 20mhz to 4mhz.
I still have some doubts on the circuit, can somebody post the real circuit schematic?
Just to show my circuit:
is something wrong with him? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Oct 14, 2009 5:18 pm |
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It worked for me. I changed the software in the 18F2580 test code,
http://www.ccsinfo.com/forum/viewtopic.php?t=40202&start=22
so that the #use delay() was 4 MHz instead of 20 MHz.
Check your connections and make sure you compiled the software
separately for board #1 and board #2. Make sure you know how
to do that. Make sure your RS232 cable is connected to board #1. |
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ivrj
Joined: 17 Mar 2009
Posts: 7
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| Posted: Thu Oct 15, 2009 8:09 am |
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| PCM programmer wrote: | It worked for me. I changed the software in the 18F2580 test code,
http://www.ccsinfo.com/forum/viewtopic.php?t=40202&start=22
so that the #use delay() was 4 MHz instead of 20 MHz.
Check your connections and make sure you compiled the software
separately for board #1 and board #2. Make sure you know how
to do that. Make sure your RS232 cable is connected to board #1. |
I get other 2 20mhz crystal, changed back to the original code and changed delay to 20000000, but isn't working.
| PCM programmer wrote: | Does your schematic represent real hardware ? Because, there is no
MCLR circuit. There are no 100 nF ceramic caps on the Vdd pins on any
chip. Also, I would jumper the Rs pins on the MCP2551 chips to ground
for the inital tests.
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where I connect the 100nF ceramic capacitors? |
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ivrj
Joined: 17 Mar 2009
Posts: 7
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| Posted: Thu Oct 15, 2009 8:19 am |
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Error found!
I crossed the can-l can-h lines!
now it´s working fine!
Thank u PCM!!!! |
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takyonxxx
Joined: 11 Mar 2011
Posts: 1
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| MCP2551 ISIS LIBRARY |
| Posted: Fri Mar 11, 2011 7:47 am |
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HELLO..
I NEED MCP2551 ISIS LIBRARY, I SAW FROM THE PICTURE THAT YOU USE IT ON PROTEUS. PLEASE I NEED IT. MAY YOU SEND IT TO ME?
OR GIVE ME A LINK.
THANKS... |
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