Can anyone help me about CAN BUS

[Mirko]

Hi,
can anyone help me about can bus in 18F458 ???
I have just download the library 18XXX8.c and 18XXX8.h.
I make two board :

in tx board transmit ADC value

in rx board receive :

id correct
len correct
data incorrect

If I assign the adc value at id value, RX board receive adc value in id.

Thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 13436

[Eric Girard]

I'm not sure if I understood your problem but I used this library in the past and here is quick list of things I remember

- RTR packet CANNOT transfer data

-to send a message with a 16 bit variable name ADC_Value :


CanSendMessage(11 or 32 bits ID,&ADC_Value,2,CAN_TX_STD_FRAME & CAN_TX_NO_RTR_FRAME & CAN_TX_PRIORITY_0);

Note that the flag are ANDED together and you need to send a pointer to the function, not the data itself

- To receive the message :
Assume you have a 8 byte buffer (unsigned char Buffer[8])
Assume unsigned char DataLen will hold the # of byte in the message
Assume unsigned int Flags will hold status of received packet
CanReceiveMessage(&[32 bit var],&Buffer[0],&DataLen,&Flags)

-Use flag & CAN_RX_xxx constant to find how type of packet etc.
CAN_RX_STD_FRAME - 11 bit ID
CAN_RX_EXT_FRAME - 29 bit ID
CAN_RX_RTR_FRAME - RTR frame (NO DATA)
CAN_RX_INV_FRAME - Invalid frame
CAN_RX_OVF_FRAME - Overflow (you missed a message)
(please check to make sure the spelling is OK...)


I have written a CANOpen library and I am using the CAN18xx8.c lib to access the CAN bus. I did not have any problem running it on the PIC18F258

Eric Girard

:=Hi,
:=can anyone help me about can bus in 18F458 ???
:=I have just download the library 18XXX8.c and 18XXX8.h.
:=I make two board :
:=
:=in tx board transmit ADC value
:=
:=in rx board receive :
:=
:= id correct
:= len correct
:= data incorrect
:=
:=If I assign the adc value at id value, RX board receive adc value in id.
:=
:=Thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 13444

[Mirko]

I finded but I haven't nothing.
ID is correct
Len is correct

data is all the same value. Have you a new idea.
Thanks

******************************************
TX PROGRAM
******************************************
#include <18F458.h>
#use delay(clock=4000000)
#fuses XT,NOWDT,WDT1
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)

#include <can18xx8.c>

void main() {
//rx
int32 rx_id;
int in_data[8];
int rx_len;
int rx_flags;
//tx
int out_data[8];
int32 tx_id=25;
int1 tx_rtr=1;
int1 tx_ext=0;
int tx_len=2;
int tx_pri=3;
//******************
int i;

setup_adc_ports(RA0_ANALOG);
setup_adc(ADC_CLOCK_DIV_2);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
setup_comparator(FALSE);

for (i=0;i<8;i++) {
out_data[i]=0;
in_data[i]=0;
}
printf("\r\n\r\nCCS CAN EXAMPLE\r\n");

CanInitialize(0,0,1,1,1,CAN_CONFIG_DEFAULT);
set_adc_channel( 0 );
while(TRUE) {
if (CANIsTxReady()) { // tx
out_data[0] = Read_ADC();
CanSendMessage (tx_id,&out_data[0],tx_len,tx_pri & tx_ext & tx_rtr);
}
}
}

**********************************************
RX PROGRAM
**********************************************
#include <18F458.h>
#use delay(clock=4000000)
#fuses XT,NOWDT,WDT1
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)

#include <can18xx8.c>

void main() {
//rx

struct rx_stat {
int1 err_ovfl;
int filthit:3;
int1 buffer;
int1 rtr;
int1 ext;
int1 inv;
};
struct rx_stat rxstat;
int32 rx_id;
int in_data[8];
int rx_len;
int rx_flags;

//tx
int out_data[8];
int32 tx_id=25;
int1 tx_rtr=1;
int1 tx_ext=0;
int tx_len=2;
int tx_pri=3;

//******************
int i;

setup_adc_ports(RA0_ANALOG);
setup_adc(ADC_CLOCK_DIV_2);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
setup_comparator(FALSE);

for (i=0;i<8;i++) {
out_data[i]=0;
in_data[i]=0;
}
printf("\r\n\r\nCCS CAN EXAMPLE\r\n");
CanInitialize(0,0,1,1,1,CAN_CONFIG_DEFAULT);

set_adc_channel( 0 );

while(TRUE) {
delay_ms (2000);
if (CANIsRxReady()) { // rx
CanReceiveMessage(&rx_id,&in_data[0],&rx_len,&rx_flags);
printf("\r\n RX ID : \%lu RX LEN : \%u RX FLAGS : \%u",rx_id,rx_len,rx_flags);
printf("\r\n");
for (i=0;i printf(" \%X ",in_data[i]);
}
printf("\r\n");
}
}
}

*********************************************
:=I'm not sure if I understood your problem but I used this library in the past and here is quick list of things I remember
:=
:=- RTR packet CANNOT transfer data
:=
:=-to send a message with a 16 bit variable name ADC_Value :
:=
:=
:= CanSendMessage(11 or 32 bits ID,&ADC_Value,2,CAN_TX_STD_FRAME & CAN_TX_NO_RTR_FRAME & CAN_TX_PRIORITY_0);
:=
:= Note that the flag are ANDED together and you need to send a pointer to the function, not the data itself
:=
:=- To receive the message :
:= Assume you have a 8 byte buffer (unsigned char Buffer[8])
:= Assume unsigned char DataLen will hold the # of byte in the message
:= Assume unsigned int Flags will hold status of received packet
:= CanReceiveMessage(&[32 bit var],&Buffer[0],&DataLen,&Flags)
:=
:= -Use flag & CAN_RX_xxx constant to find how type of packet etc.
:= CAN_RX_STD_FRAME - 11 bit ID
:= CAN_RX_EXT_FRAME - 29 bit ID
:= CAN_RX_RTR_FRAME - RTR frame (NO DATA)
:= CAN_RX_INV_FRAME - Invalid frame
:= CAN_RX_OVF_FRAME - Overflow (you missed a message)
:= (please check to make sure the spelling is OK...)
:=
:=
:=I have written a CANOpen library and I am using the CAN18xx8.c lib to access the CAN bus. I did not have any problem running it on the PIC18F258
:=
:=Eric Girard
___________________________
This message was ported from CCS's old forum
Original Post ID: 13462

[Mirko]

OK I resolve my problem Thenk you a lot.
If anyone interessed I write after the example :

by Mirko
*********************************************************
#include <18F458.h>
#use delay(clock=4000000)
#fuses XT,NOWDT,WDT1
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)

#include <can18xx8.c>


void main() {
//rx
int32 rx_id;
int in_data[8];
int rx_len;
int rx_flags;

//tx
int out_data[8];
int32 tx_id=25;
int1 tx_rtr=1;
int1 tx_ext=0;
int tx_len=1;
int tx_pri=3;

//******************
int i;
int tx_app;
int rx_app;

setup_adc_ports(RA0_ANALOG);
setup_adc(ADC_CLOCK_DIV_2);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
setup_comparator(FALSE);


for (i=0;i<8;i++) {
out_data[i]=0;
in_data[i]=0;
}
printf("\r\n\r\nCCS CAN EXAMPLE\r\n");
CanInitialize(0,64,4,4,4,CAN_CONFIG_DEFAULT);

set_adc_channel( 0 );


while(TRUE) {

if (CANIsTxReady()) { // tx
out_data[0]=READ_adc();
CanSendMessage (tx_id,&out_data[0],tx_len,CAN_TX_STD_FRAME & CAN_TX_NO_RTR_FRAME & CAN_TX_PRIORITY_0);
}

delay_ms (2000);
if (CANIsRxReady()) { // rx
CanReceiveMessage(&rx_id,&in_data[0],&rx_len,&rx_flags);
printf("\r\n RX ID : \%lu RX LEN : \%u RX FLAGS : \%u",rx_id,rx_len,rx_flags);
printf("\r\n");
for (i=0;i printf(" \%X ",in_data[i]);
}
printf("\r\n");
}

}

}

**********************************************************


:=I'm not sure if I understood your problem but I used this library in the past and here is quick list of things I remember
:=
:=- RTR packet CANNOT transfer data
:=
:=-to send a message with a 16 bit variable name ADC_Value :
:=
:=
:= CanSendMessage(11 or 32 bits ID,&ADC_Value,2,CAN_TX_STD_FRAME & CAN_TX_NO_RTR_FRAME & CAN_TX_PRIORITY_0);
:=
:= Note that the flag are ANDED together and you need to send a pointer to the function, not the data itself
:=
:=- To receive the message :
:= Assume you have a 8 byte buffer (unsigned char Buffer[8])
:= Assume unsigned char DataLen will hold the # of byte in the message
:= Assume unsigned int Flags will hold status of received packet
:= CanReceiveMessage(&[32 bit var],&Buffer[0],&DataLen,&Flags)
:=
:= -Use flag & CAN_RX_xxx constant to find how type of packet etc.
:= CAN_RX_STD_FRAME - 11 bit ID
:= CAN_RX_EXT_FRAME - 29 bit ID
:= CAN_RX_RTR_FRAME - RTR frame (NO DATA)
:= CAN_RX_INV_FRAME - Invalid frame
:= CAN_RX_OVF_FRAME - Overflow (you missed a message)
:= (please check to make sure the spelling is OK...)
:=
:=
:=I have written a CANOpen library and I am using the CAN18xx8.c lib to access the CAN bus. I did not have any problem running it on the PIC18F258
:=
:=Eric Girard
:=
:=:=Hi,
:=:=can anyone help me about can bus in 18F458 ???
:=:=I have just download the library 18XXX8.c and 18XXX8.h.
:=:=I make two board :
:=:=
:=:=in tx board transmit ADC value
:=:=
:=:=in rx board receive :
:=:=
:=:= id correct
:=:= len correct
:=:= data incorrect
:=:=


:=:=If I assign the adc value at id value, RX board receive adc value in id.
:=:=
:=:=Thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 13501

[MoofCba]

Can you share your CanOpen library?

[PCM programmer]

Look at AN945 from Microchip:
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en020605

[ozzy]

microchip's source not for ccs compiler. Should you share your canopen source?