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mat72
Joined: 19 Jan 2006
Posts: 11
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| help with 18F4550, SPI, MCP2510 |
 Posted: Fri Mar 09, 2007 10:47 am |
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Hi, I'm having trouble with connecting the MCP2510. my program crashes on the can_init() function. Actually I've never interface anything via SPI before. Anyways here is what I have
The MCP is interfaced as follows
PIC MCP
C7/SDO -> pin15 SO
B1/SCK -> pin13 SCK
B0/SDI -> pin14 SI
other MCP connections
Vdd -> +5
reset -> pulled +5 and connected to PIC reset button
CS_ -> GND (only using the one SPI device)
Vss ->GND
TXCAN - > TXD trans
RXCAN -> RXD trans
The pic code is based on some USB code I was, so that is were the fuse settings come from. I also have a USB bootloader.
I removed PIN_C7 here because its being used for SPI
#use rs232(baud=19200, xmit=PIN_C6)//, rcv=PIN_C7)
| Code: |
#include <18F4550.h>
#fuses HSPLL,NOWDT,NOPROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
// for USB boot loader
#build(reset=0x800, interrupt=0x808)
#org 0x000, 0x7ff { }
#use rs232(baud=19200, xmit=PIN_C6)//, rcv=PIN_C7)
#include "lcd420D.c"
#include <can-mcp2510.c>
#define DEVICE_ID 255
long seconds = 0; // A running seconds counter
unsigned byteCount = 0;
BYTE UART_EVENT = 0;
BYTE PACKET_RECEIVED = 0;
// CAN
#define RESPOND_TO_ID_AD 0x201
#define RESPOND_TO_ID_LED 0x202
struct rx_stat rxstat;
int32 rx_id;
int canBuffer[8];
int rx_len;
#include "timers.h"
#include "tasks.c"
#include "ISRs.c"
void main() {
seconds = 0;
set_tris_e(0);
// set the incoming packet message to all zeros
memset(&msg,0,4);
// == 200 ints per second
setup_timer_2 ( T2_DIV_BY_16, 250, 15);
set_timer2(0);
enable_interrupts(INT_TIMER2);
enable_interrupts(int_rda);
ext_int_edge(H_TO_L); // init interrupt triggering for button press
setup_adc_ports(AN0_TO_AN1);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
delay_ms(200);
lcd_init();
delay_ms(200);
enable_interrupts(GLOBAL);
can_init();
lcd_putc("Ready...\n");
printf("Running..\r\n");
delay_ms(1000);
while (TRUE) {
taskPollInput();
taskCanHandler();
taskUART();
taskProcessInPacket();
taskRespondToCCU();
taskUpdateHub();
taskUpdateDisplay();
taskSecondCount();
}
}
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Here is the code for my taskCanHandler() task.
| Code: |
void taskCanHandler(){
if ( can_kbhit() ) //if data is waiting in buffer...
{
if(can_getd(rx_id, &canBuffer[0], rx_len, rxstat)) { //...then get data from buffer
if (rx_id == RESPOND_TO_ID_LED) {
lcd_gotoxy(1,4);
printf(lcd_putc,"CAN id:%lu", rx_id);
}
else{
lcd_gotoxy(1,4);
printf(lcd_putc,"CcAN id:%lu", rx_id);
}
}
}
}
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And just in case: here are my isr's
| Code: |
#INT_TIMER2
void clock_isr() {
if(timerPollInput) timerPollInput--;
if(timerUART) timerUART--;
if(timerRespondToCCU) timerRespondToCCU--;
if(timerUpdateHub) timerUpdateHub--;
if(timerDisplay) timerDisplay--;
if(timerSecCount) timerSecCount--;
}
#int_rda
void serial_isr() {
static int t;
byteCount++;
UART_EVENT = 1;
buffer[next_in]=getc();
TEST = buffer[next_in];
t=next_in;
next_in=(next_in+1) % BUFFER_SIZE;
if(next_in==next_out){
next_in=t; // Buffer full !!
}
}
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 09, 2007 1:55 pm |
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| Quote: |
PIC MCP2510
C7/SDO -> pin15 SO
B1/SCK -> pin13 SCK
B0/SDI -> pin14 SI
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The SDI and SDO connections are wrong. SDO on the PIC must go
to SDI on the MCP2510. Output goes to input. Then the SDO on
the MCP2510 must go to the SDI pin on the PIC.
Also, I wouldn't tie the \CS pin to ground. For all we know, the internal
hardware state machine inside the MCP2510 may be looking for the
level changes on the chip select pin. It may work. I've never tried it.
But it's an extra experiment and it doesn't need to be done at this time.
The can-mcp2510.c driver expects to use it and I would hook it up just
as the driver says.
There are a few other things. I wouldn't put in the USB bootloader code
at the same time that you're trying to bring up the MCP2510. I would
get rid of all the #org's and #build statements.
You've removed the UART receiver by commenting out "rcv=PIN_C7"
from the #use rs232 statement. But your main code still has a line
in it to enable INT_RDA interrupts. That line should be removed.
Also, be aware that when only the transmitter is defined in the #use rs232
statement, the compiler will create a software UART. It won't use the
hardware UART. |
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mat72
Joined: 19 Jan 2006
Posts: 11
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| Posted: Fri Mar 09, 2007 3:07 pm |
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Thanks, I'll give it a try. Is it necessary to get rid of the USB bootloader? I find it great.
Thanks,
Matt |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 09, 2007 3:22 pm |
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If it works, use it. My concern was that while you're bringing up a
new peripheral chip, any extraneous code cound introduce confusion
with regard to finding the problems. |
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mat72
Joined: 19 Jan 2006
Posts: 11
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| Posted: Fri Mar 09, 2007 6:46 pm |
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| right now thats how I'm uploading the code. My programmer is packed up somewhere. I made the other fixes and its still crashing on the init code |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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