STM32F4 Can-Bus Problem

[doganayserhatt]

Posted on October 09, 2015 at 22:37

The original post was too long to process during our migration. Please click on the attachment to read the original post.

[jpeacock]

Posted on October 09, 2015 at 22:49

Look at the two CAN_ESR registers to determine the error.  Do you have twisted pair between both nodes, and 120 ohm termination at each end?

  Jack Peacock

[doganayserhatt]

Posted on October 09, 2015 at 22:59

First, thank you peacock.jack.003 for fast reply. Yep. I used  120 ohm resistor between can_H and can_L. In addition, USART6 can't run. No data doesn't appear. I use 2 x MCP2551 for Can1 and Can2 node. 

[Tesla DeLorean]

Posted on October 10, 2015 at 00:36

You'd need to have code to associate the USART6 with the STDIO functionality.

//******************************************************************************
// Hosting of stdio functionality through USART6
//******************************************************************************
#include <
rt_misc.h
>
#pragma import(__use_no_semihosting_swi)
struct __FILE { int handle; /* Add whatever you need here */ };
FILE __stdout;
FILE __stdin;
int fputc(int ch, FILE *f)
{
while(USART_GetFlagStatus(USART6, USART_FLAG_TXE) == RESET);
USART_SendData(USART6, ch);
return(ch);
}
int fgetc(FILE *f)
{
char ch;
while(USART_GetFlagStatus(USART6, USART_FLAG_RXNE) == RESET);
ch = USART_ReceiveData(USART6);
return((int)ch);
}
int ferror(FILE *f)
{
/* Your implementation of ferror */
return EOF;
}
void _ttywrch(int ch)
{
while(USART_GetFlagStatus(USART6, USART_FLAG_TXE) == RESET);
USART_SendData(USART6, ch);
}
void _sys_exit(int return_code)
{
label: goto label; /* endless loop */
}

[doganayserhatt]

Posted on October 10, 2015 at 10:03

Thank you clive1, How do I associate this code with STDIO functionatily? Where do I add this code?

[Tesla DeLorean]

Posted on October 10, 2015 at 16:38

Where do I add this code?

Anywhere in your project. The system has no knowledge of how the data gets to the serial port unless you provide a route, in the manner provided here.

Please review Keil documentation for more background

http://www.keil.com/support/man/docs/gsac/gsac_retargetcortex.htm

[doganayserhatt]

Posted on October 10, 2015 at 20:16

Thanks clive1. I will read that one.  I added that code block in the main program. But, This code can't work still. I used USART2, When i push reset button, meaningless character view in my serialport Program. I show you my schematic.

Schematic diagram : http://i57.tinypic.com/x0ra5j.jpg

[Tesla DeLorean]

Posted on October 11, 2015 at 02:55

Make sure HSE_VALUE is correctly define as 8000000 in you project (often stm32f4xx_conf.h) and the PLL settings assume an 8 MHz source.

Get you serial port output working so you have some chance of debugging/diagnosing your issues.

Circuit does not appear unreasonable.

[doganayserhatt]

Posted on October 11, 2015 at 09:58

I defined HSE_VALUE=8000000 in the Options for target-> C/C++. But it can't work. I will try with logic analyzer. I ordered it. I will share result here. Thanks clive1..