Managed C++/CLI

Re: Is there anyone have experience in programming Controller Area Network?

14-Dec-10 23:11

Hi,

I need to program PIC 16F876A to control MCP2515 CAN controller? Anyone got any experience or example to shared? I having trouble in understanding the example code i found.

/*
 * Project name:
     Can_1st (CAN Network demonstration with mikroE's CAN module)
 * Copyright:
     (c) MikroElektronika, 2005-2008
 * Description:
     This project is a simple demonstration of CAN on PIC18F448 with minor
     adjustments, it should work with any other MCU that has a CAN module.
     This code demonstrates how to use CAN library functions and procedures.
     It is used together with the CAN_2nd example (on second MCU), and it can
     be used to test the connection of MCU to the CAN network.
     This node initiates the communication with the Can_2nd node by sending some
     data to its address. The 2nd node responds by sending back the data incre-
     mented by 1. This (1st) node then does the same and sends incremented data
     back to 2nd node, etc.
 * Test configuration:
     MCU:             PIC18F448
     Dev.Board:       EasyPIC6
                      http://www.mikroe.com/en/tools/easypic6/
     Oscillator:      HS, 8.0000 MHz
     Ext. Modules:    mE CAN extra board on PORTB
                      http://www.mikroe.com/en/tools/can1/
     SW:              mikroC PRO for PIC
                      http://www.mikroe.com/en/compilers/mikroc/pro/pic/
 * NOTES:
     - Consult the CAN standard about CAN bus termination resistance.
     - Turn off LEDs SW9.2 and pull-up (place jumper in upper position)  (board specific)
       lines on PORTB. mE CAN extra board should be connected to PORTB.
     - Turn on LEDs on PORTC (SW9.3) (board specific)
 */

unsigned char Can_Init_Flags, Can_Send_Flags, Can_Rcv_Flags; // can flags
unsigned char Rx_Data_Len;                                   // received data length in bytes
char RxTx_Data[8];                                           // can rx/tx data buffer
char Msg_Rcvd;                                               // reception flag
const long ID_1st = 12111, ID_2nd = 3;                       // node IDs
long Rx_ID;

void main() {

  PORTC = 0;                                                // clear PORTC
  TRISC = 0;                                                // set PORTC as output

  Can_Init_Flags = 0;                                       //
  Can_Send_Flags = 0;                                       // clear flags
  Can_Rcv_Flags  = 0;                                       //

  Can_Send_Flags = _CAN_TX_PRIORITY_0 &                     // form value to be used
                   _CAN_TX_XTD_FRAME &                      //     with CANWrite
                   _CAN_TX_NO_RTR_FRAME;

  Can_Init_Flags = _CAN_CONFIG_SAMPLE_THRICE &              // form value to be used
                   _CAN_CONFIG_PHSEG2_PRG_ON &              // with CANInit
                   _CAN_CONFIG_XTD_MSG &
                   _CAN_CONFIG_DBL_BUFFER_ON &
                   _CAN_CONFIG_VALID_XTD_MSG;
  
  CANInitialize(1,3,3,3,1,Can_Init_Flags);                  // Initialize CAN module
  CANSetOperationMode(_CAN_MODE_CONFIG,0xFF);               // set CONFIGURATION mode
  CANSetMask(_CAN_MASK_B1,-1,_CAN_CONFIG_XTD_MSG);          // set all mask1 bits to ones
  CANSetMask(_CAN_MASK_B2,-1,_CAN_CONFIG_XTD_MSG);          // set all mask2 bits to ones
  CANSetFilter(_CAN_FILTER_B2_F4,ID_2nd,_CAN_CONFIG_XTD_MSG);// set id of filter B2_F4 to 2nd node ID

  CANSetOperationMode(_CAN_MODE_NORMAL,0xFF);               // set NORMAL mode

  RxTx_Data[0] = 9;                                         // set initial data to be sent

  CANWrite(ID_1st, RxTx_Data, 1, Can_Send_Flags);           // send initial message

  while(1) {                                                               // endless loop
    Msg_Rcvd = CANRead(&Rx_ID , RxTx_Data , &Rx_Data_Len, &Can_Rcv_Flags); // receive message
    if ((Rx_ID == ID_2nd) && Msg_Rcvd) {                                   // if message received check id
      PORTC = RxTx_Data[0];                                                // id correct, output data at PORTC
      RxTx_Data[0]++ ;                                                     // increment received data
      Delay_ms(10);
      CANWrite(ID_1st, RxTx_Data, 1, Can_Send_Flags);                      // send incremented data back
    }
  }
}

/*
 * Project name:
     Can_2nd (CAN Network demonstration with mikroE's CAN module)
 * Copyright:
     (c) MikroElektronika, 2005-2008
 * Description:
     This project is a simple demonstration of CAN on PIC18F448 with minor
     adjustments, it should work with any other MCU that has a CAN module.
     This code demonstrates how to use CAN library functions and procedures.
     It is used together with the Can_1st example (on second MCU), and it can
     be used to test the connection of MCU to the CAN network.
     This node receives data, increments it by 1 and send it back to the 1st node.
 * Test configuration:
     MCU:             PIC18F448
     Dev.Board:       EasyPIC6
                      http://www.mikroe.com/en/tools/easypic6/
     Oscillator:      HS, 8.0000 MHz
     Ext. Modules:    mE CAN extra board on PORTB
                      http://www.mikroe.com/en/tools/can1/
     SW:              mikroC PRO for PIC
                      http://www.mikroe.com/en/compilers/mikroc/pro/pic/
 * NOTES:
    - Consult the CAN standard about CAN bus termination resistance.
    - Turn off LEDs SW9.2 and pull-up (place jumper in upper position)  (board specific)
      lines on PORTB. mE CAN extra board should be connected to PORTB.
    - Turn on LEDs on PORTC (SW9.3) (board specific)
 */

unsigned char Can_Init_Flags, Can_Send_Flags, Can_Rcv_Flags; // can flags
unsigned char Rx_Data_Len;                                   // received data length in bytes
char RxTx_Data[8];                                           // can rx/tx data buffer
char Msg_Rcvd;                                               // reception flag
const long ID_1st = 12111, ID_2nd = 3;                       // node IDs
long Rx_ID;

void main() {

  PORTC = 0;                                                // clear PORTC
  TRISC = 0;                                                // set PORTC as output

  Can_Init_Flags = 0;                                       //
  Can_Send_Flags = 0;                                       // clear flags
  Can_Rcv_Flags  = 0;                                       //

  Can_Send_Flags = _CAN_TX_PRIORITY_0 &                     // form value to be used
                   _CAN_TX_XTD_FRAME &                      //     with CANWrite
                   _CAN_TX_NO_RTR_FRAME;

  Can_Init_Flags = _CAN_CONFIG_SAMPLE_THRICE &              // form value to be used
                   _CAN_CONFIG_PHSEG2_PRG_ON &              // with CANInit
                   _CAN_CONFIG_XTD_MSG &
                   _CAN_CONFIG_DBL_BUFFER_ON &
                   _CAN_CONFIG_VALID_XTD_MSG &
                   _CAN_CONFIG_LINE_FILTER_OFF;

  CANInitialize(1,3,3,3,1,Can_Init_Flags);                  // initialize external CAN module
  CANSetOperationMode(_CAN_MODE_CONFIG,0xFF);               // set CONFIGURATION mode
  CANSetMask(_CAN_MASK_B1,-1,_CAN_CONFIG_XTD_MSG);          // set all mask1 bits to ones
  CANSetMask(_CAN_MASK_B2,-1,_CAN_CONFIG_XTD_MSG);          // set all mask2 bits to ones
  CANSetFilter(_CAN_FILTER_B2_F3,ID_1st,_CAN_CONFIG_XTD_MSG);// set id of filter B2_F3 to 1st node ID

  CANSetOperationMode(_CAN_MODE_NORMAL,0xFF);               // set NORMAL mode

  while (1) {                                                              // endless loop
    Msg_Rcvd = CANRead(&Rx_ID , RxTx_Data , &Rx_Data_Len, &Can_Rcv_Flags); // receive message
    if ((Rx_ID == ID_1st) && Msg_Rcvd) {                                   // if message received check id
      PORTC = RxTx_Data[0];                                                // id correct, output data at PORTC
      RxTx_Data[0]++ ;                                                     // increment received data
      CANWrite(ID_2nd, RxTx_Data, 1, Can_Send_Flags);                      // send incremented data back
    }
  }
}

Luc Pattyn15-Dec-10 2:22

Re: Is there anyone have experience in programming Controller Area Network?

15-Dec-10 2:22

Hi,

1.
you're asking in the wrong forum: C++/CLI is the .Net version of C++, not the PIC version! I will not proceed here beyond this single reply.

2.
I have done lots of CAN applications, and I have used several PIC models, however I never did real CAN on PIC (I have a CAN-like protocol running on a tiny PIC, all in software though). So all I can offer is a set of advice:

3.
make sure you read all you can get about CAN in general, and thoroughly read your PIC's documentation. Peripherals need a lot of initialization (see the start of your Main functions), and a single error or omission there may cause total failure.

4.
Your test set-up is sending basically the same message back and forth from one PIC to the other, it does not offer any observability: it could be running fine without you noticing anything, or it could fail completely, how can you tell? I suggest you connect a few LEDs (or any other output device) and set their value inside the while loop; displaying a few bits of RxTx_Data[0] should generate an incrementing binary pattern. Observability is key in all debugging, and often is even more important on embedded systems; take care of it from the start, the payback will be immediate.

5.
For any serious application you would need interrupts, and probably also CAN message filtering (assuming multiple PIC nodes and a rather busy CAN bus). Your test has neither. So it may become much more complex.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

kent524415-Dec-10 6:54

My last CAN reply in this forum.

15-Dec-10 6:54

Thanks for your advices and I am sorry because I am confused where to post my question since the source code is in .c file type so I am thought i can post it in C++.

It would be great if u can gives me some link to some example of CAN using PIC since I can't really find one that I manage to understood.

Luc Pattyn15-Dec-10 7:08

15-Dec-10 7:08

use either the hardware forum or the C/C++ forum. I will probably see it where ever you put it!

search for:
PIC application notes
PIC AN738
TCanDriver
16F876 CAN source code

if you need more help, ask specific questions; however begin with providing detailed context: are you using a kernel/operating system? do you need to interact with existing CAN nodes? if so, what specific CAN protocol do you need? what is the application? what is the bit rate, the bus load to be expected, the rate of *other* interrupts, etc etc.

Embedded systems aren't simple. If this were your first experiment, start with simpler things: a few LEDs (needed anyway for debugging), a serial port. When you feel comfortable, switch to more complex stuff (such as USB, Ethernet, CAN).

End of thread.

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

kent524415-Dec-10 7:19

15-Dec-10 7:19

yea, this is the first time I experiment with CAN. I was confuse where to start with. I have already collected and roughly go through the data sheet for each PIC needed. After that, I drawn the circuit diagram and then tried to understand the source code I posted above but its too complicated for a beginner like me.

I really appreciated your prompt reply. I think i should make myself more clear before I ask questions.

Thanks again for your prompt reply. Hope to receive your reply for my future question. Smile | :)

kent52449-Jan-11 22:32

9-Jan-11 22:32

Hi Luc Pattyn,

Do you used simulation to run your CAN project? If yes, may I know what is the simulator? I have a proteus 7 software which can do simulation job, but the problem is the software dont have MCP 2551 and MCP 2515 device. I cant find the library.

I have done a simple program but it does not run when i burn into the microcontroller (pic 16f877). There is no compilation error also.

CAN node 1

unsigned char Can_Init_Flags, Can_Send_Flags, Can_Rcv_Flags; // can flags
unsigned char Rx_Data_Len;                                   // received data length in bytes
char RxTx_Data[8];                                           // can rx/tx data buffer
char Msg_Rcvd;                                               // reception flag
const long ID_1st = 12111, ID_2nd = 3;                       // node IDs
long Rx_ID;

// CANSPI module connections
sbit CanSpi_CS            at  RC0_bit;
sbit CanSpi_CS_Direction  at  TRISC0_bit;
sbit CanSpi_Rst           at  RC2_bit;
sbit CanSpi_Rst_Direction at  TRISC2_bit;
// End CANSPI module connections

void main() {

  PORTA = 0x00;                                             // clear PORTA
  TRISA = 0xFF;                                             // set PORTA as input

  //PORTB = 0x00;                                             // clear PORTB
  //TRISB = 0x00;                                             // set PORTB as output
  
  //PORTC = 0x00;                                             // clear PORTC
  //TRISC = 0x00;                                             // set PORTC as output
  
  PORTD = 0x00;                                             // clear PORTD
  TRISD = 0x00;                                             // set PORTD as output

  Can_Init_Flags = 0;                                         //
  Can_Send_Flags = 0;                                         // clear flags
  Can_Rcv_Flags  = 0;                                         //

  Can_Send_Flags = _CANSPI_TX_PRIORITY_0 &                    // form value to be used
                   _CANSPI_TX_XTD_FRAME &                     //     with CANSPIWrite
                   _CANSPI_TX_NO_RTR_FRAME;

  Can_Init_Flags = _CANSPI_CONFIG_SAMPLE_THRICE &             // Form value to be used
                   _CANSPI_CONFIG_PHSEG2_PRG_ON &             //  with CANSPIInit
                   _CANSPI_CONFIG_XTD_MSG &
                   _CANSPI_CONFIG_DBL_BUFFER_ON &
                   _CANSPI_CONFIG_VALID_XTD_MSG;


  SPI1_Init();                                                     // initialize SPI1 module

  CANSPIInitialize(1,3,3,3,1,Can_Init_Flags);                      // Initialize external CANSPI module
  CANSPISetOperationMode(_CANSPI_MODE_CONFIG,0xFF);                // set CONFIGURATION mode
  CANSPISetMask(_CANSPI_MASK_B1,-1,_CANSPI_CONFIG_XTD_MSG);        // set all mask1 bits to ones
  CANSPISetMask(_CANSPI_MASK_B2,-1,_CANSPI_CONFIG_XTD_MSG);        // set all mask2 bits to ones
  CANSPISetFilter(_CANSPI_FILTER_B2_F4,ID_2nd,_CANSPI_CONFIG_XTD_MSG);// set id of filter B2_F4 to 2nd node ID

  CANSPISetOperationMode(_CANSPI_MODE_NORMAL,0xFF);                // set NORMAL mode

  RxTx_Data[0] = 9;                                                // set initial data to be sent

  CANSPIWrite(ID_1st, RxTx_Data, 1, Can_Send_Flags);               // send initial message
}

CAN node2

unsigned char Can_Init_Flags, Can_Send_Flags, Can_Rcv_Flags; // can flags
unsigned char Rx_Data_Len;                                   // received data length in bytes
char RxTx_Data[8];                                           // can rx/tx data buffer
char Msg_Rcvd;                                               // reception flag
const long ID_1st = 12111, ID_2nd = 3;                       // node IDs
long Rx_ID;

// CANSPI module connections
sbit CanSpi_CS            at  RC0_bit;
sbit CanSpi_CS_Direction  at  TRISC0_bit;
sbit CanSpi_Rst           at  RC2_bit;
sbit CanSpi_Rst_Direction at  TRISC2_bit;
// End CANSPI module connections

void main() {

  PORTA = 0x00;                                               // clear PORTA
  TRISA = 0x00;                                               // set PORTA as output

  PORTD = 0x00;                                               // clear PORTD
  TRISD = 0x00;                                               // set PORTD as output

  Can_Init_Flags = 0;                                         //
  Can_Send_Flags = 0;                                         // clear flags
  Can_Rcv_Flags  = 0;                                         //

  Can_Send_Flags = _CANSPI_TX_PRIORITY_0 &                    // form value to be used
                   _CANSPI_TX_XTD_FRAME &                     //   with CANSPIWrite
                   _CANSPI_TX_NO_RTR_FRAME;

  Can_Init_Flags = _CANSPI_CONFIG_SAMPLE_THRICE &             // Form value to be used
                   _CANSPI_CONFIG_PHSEG2_PRG_ON &             //  with CANSPIInit
                   _CANSPI_CONFIG_XTD_MSG &
                   _CANSPI_CONFIG_DBL_BUFFER_ON &
                   _CANSPI_CONFIG_VALID_XTD_MSG &
                   _CANSPI_CONFIG_LINE_FILTER_OFF;

  SPI1_Init();                                                                       // initialize SPI1 module

  CANSPIInitialize(1,3,3,3,1,Can_Init_Flags);                                        // initialize external CANSPI module
  CANSPISetOperationMode(_CANSPI_MODE_CONFIG,0xFF);                                  // set CONFIGURATION mode
  CANSPISetMask(_CANSPI_MASK_B1,-1,_CANSPI_CONFIG_XTD_MSG);                          // set all mask1 bits to ones
  CANSPISetMask(_CANSPI_MASK_B2,-1,_CANSPI_CONFIG_XTD_MSG);                          // set all mask2 bits to ones
  CANSPISetFilter(_CANSPI_FILTER_B2_F3,ID_1st,_CANSPI_CONFIG_XTD_MSG);               // set id of filter B2_F3 to 1st node ID

  CANSPISetOperationMode(_CANSPI_MODE_NORMAL,0xFF);                                  // set NORMAL mode
  
  Msg_Rcvd = CANSPIRead(&Rx_ID , RxTx_Data , &Rx_Data_Len, &Can_Rcv_Flags);

  if ((Rx_ID == ID_1st) && Msg_Rcvd) {                                               
  PORTD = 0x01;                                    // if id is valid, port D will have output of 0000 0001  
  }
  else
  PORTD = 0x08;                                    // else port D will have output of 0000 1000
}

The result is 0000 1000, which means node 2 does not received any message from node 1.

I hope you can advise me in this problem. Thanks.

Luc Pattyn10-Jan-11 1:40

10-Jan-11 1:40

No, we never used simulation for CAN. I am also unfamiliar with CANSPI library, we used our own code, directly accessing the hardware.

Some thoughts:
1.
If the first node sends before the second got through initialization, the message would be lost. Having both nodes powered by the same supply (just a guess), and/or even connected to the same reset line, would still leave a timing uncertainty on which starts up first, and how big the launch time difference would be (tens of msec easily).

2.
is CANSPIRead() a blocking function? and would it work right after initialization?

Suggestion: I would make one node send one message per second, say an incrementing number; then see of the second node gets anything at all.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] [My CP bug tracking] Nil Volentibus Arduum

Season's Greetings to all CPians.

kent524411-Jan-11 6:40

11-Jan-11 6:40

Hi,

Hmm, so you are suggesting that I should have several lines of CANSPIWrite()?
There are many things that I still not sure....I just experiment with it.

However, thanks a lot for your prompt reply.

regards,
kent

kent524412-Jan-11 16:03

12-Jan-11 16:03

Hi Luc Pattyn,

I have one favor to ask. Can you take a look on my system diagram? I want to make sure that my connection is ok. However, I don't know how to upload the image on this forum. I can email my system diagram to you, if you are fine with it.

Thanks.

Regards,
Kent

CAN diagram

Luc Pattyn12-Jan-11 16:09

12-Jan-11 16:09

You need some Gold or Platinum reputation around here to get upload capabilities.
However you could upload to some public service (such as Flickr), then post the link here.

BTW: You are totally abusing this forum, even more than when you started this thread.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

Re: CAN diagram

kent524412-Jan-11 17:45

12-Jan-11 17:45

Hi Luc Pattyn

Abusing the forum? May I know in which aspect? I will try not to do it again.

I have uploaded my system diagram to my facebook account. I hope you able to see the system diagram.

http://l7.sphotos.l3.fbcdn.net/hphotos-l3-snc6/hs040.snc6/167023_10150096622433617_771988616_5797105_6651352_n.jpg[^]

regards
kent

Re: CAN diagram

Luc Pattyn12-Jan-11 18:21

How to convert SAFEARRAY to System::Object

12-Jan-11 18:21

I haven't checked the diagram against the datasheets or application notes from the manufacturer, you should if you haven't already. There aren't many ways to connect things up anyway.

kent5244 wrote:
Abusing the forum?

I suggest you read again the very first sentence I've replied in this thread.

Hmmm | :|

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

ptr_Electron13-Dec-10 0:19

ptr_Electron

13-Dec-10 0:19

May I know how to convert SAFEARRAY to System::Object,

error C2664: void .....(System::String ^,System::Object ^)' : cannot convert parameter 2 from 'SAFEARRAY *' to 'System::Object ^'

thanks

Re: How to convert SAFEARRAY to System::Object

Radhakrishnan G.14-Dec-10 21:06

Radhakrishnan G.

14-Dec-10 21:06

Marshal.GetObjectForNativeVariant Method[^]

How to use C DLL in C++/CLI

cancerion2-Dec-10 0:32

cancerion

2-Dec-10 0:32

Hi,

I m new to CLI ,
Can anyone tell me How to use C DLL in C++/CLI???

Thanks,
Sachin

Re: How to use C DLL in C++/CLI

Luc Pattyn2-Dec-10 2:00