CAN-loopback mode

khoichi · Guest

can someone give me an overview on how to get into LOOPBACK MODE? I'm using the libraries can18xxx8.c and can18.xxx8.h. I want to test what's in the recieve buffers of PIC18F2480.

thanks

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

I wonder if there are really this many different people working
on the 18F2480 ?

But anyway, here is a thread that shows how to put the 18F458 in
loopback mode with the CCS drivers.
http://www.ccsinfo.com/forum/viewtopic.php?t=20106&highlight=loopback

Arlene · Guest

when we tried to put it in loopback mode and print out what was received, we got nothing. what could be wrong?

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Just get a 18F458 and use it to learn the CAN bus.
You have spent weeks on the 18F2480 and it doesn't work.
How much time do you intend to waste on this chip ?

In your code in the other thread,
http://www.ccsinfo.com/forum/viewtopic.php?t=23811
you've taken pieces of the CCS EX_CAN.C demo program,
but you've left out important parts. You're calling can_getd()
without checking to see if any messages are available by
first calling can_kbhit(). CCS shows completely how to
do it in EX_CAN.C, but you have ignored it.

Arlene · Guest

It works! Thanks. The can_getd function didn't work, so we wrote our own and figured it out.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

For CAN bus loopback code, see this thread. Newguy is using a
18F4580, which is similar to your 18F2480. If the code works
for his PIC, then it probably will work with the 18F2480.
http://www.ccsinfo.com/forum/viewtopic.php?t=23825