CAN bus and 18F248

[Aryldo G Russo Jr]

Hi all,

Does anyone have any experience with CAN bus and 18F248?

I'm trying to implement this protocol, but I got stuck just after I have the configuration done.

I'm using CCS C 3.168, and I can see, using the watch windows, that after I send the configuration comand, it was accept correctly.

then, if I put my module in Loopback mode, I can see everything I send out in my receive buffer.

but if I put it in normal mode, I can't see anything at the scope, and the transmit error buffer has more than 255 errors, so my module goes to buf off mode.

any ideas?

Thanks

Dinho
___________________________
This message was ported from CCS's old forum
Original Post ID: 144515923

[Douglas Richard]

Do you have another working node connected to your set up?

:=Hi all,
:=
:=Does anyone have any experience with CAN bus and 18F248?
:=
:=I'm trying to implement this protocol, but I got stuck just after I have the configuration done.
:=
:=I'm using CCS C 3.168, and I can see, using the watch windows, that after I send the configuration comand, it was accept correctly.
:=
:=then, if I put my module in Loopback mode, I can see everything I send out in my receive buffer.
:=
:=but if I put it in normal mode, I can't see anything at the scope, and the transmit error buffer has more than 255 errors, so my module goes to buf off mode.
:=
:=any ideas?
:=
:=Thanks
:=
:=Dinho
___________________________
This message was ported from CCS's old forum
Original Post ID: 144515940

[Aryldo G Russo Jr]

I'm developing my first node at this time. what I tried to do was create 2 nodes, with the same firmware(under development), but even though it's not working. is there any trick that I could use to test my CAN module alone?

what do I have to do to be able to see the wave form at he scope?

Thanks

Dinho
___________________________
This message was ported from CCS's old forum
Original Post ID: 144515941

[Douglas Richard]

Make sure you drive your outputs Hi (not tristate).
___________________________
This message was ported from CCS's old forum
Original Post ID: 144515998

[Mike Broom]

:=I'm developing my first node at this time. what I tried to do was create 2 nodes, with the same firmware(under development), but even though it's not working. is there any trick that I could use to test my CAN module alone?
:=
:=what do I have to do to be able to see the wave form at he scope?
:=
:=Thanks
:=
:=Dinho

if you are driving the output correctly, and thee bus is terminated then you should see the packets of data until the device bus off's
___________________________
This message was ported from CCS's old forum
Original Post ID: 144516094