Two CAN-Shields and one UNO?

[ramaekers.pieter]

@loovee

@Norbert

@loovee

if you just want to receive message with one shield, log or edit some message and re-send them with the other shield, I don’t think you need two shield~
Actually, one is enough.
Or you can let me know more about you plan, then I can confirm that~

What I plan to do is a little different : I want to read messages on one bus with the first shield, filter out some messages and re-send the rest on a second bus with the second shield:

----BUS1----> ||SHIELD1||-->||Arduino||-->||Shield2||---->BUS2----

What I need to know is what I have to change in the wiring (CS!) or in the library to support two shields.

Ok~ you have 2 things to do.

you can see here [attachment=0]can.jpg[/attachment] , what you should is cut the connect of one shield, the connect it to D9

then one cs is D10 and the other is D9

when you control the D10 shield , add this code:

digitalWrite(9, HIGH);
digitalWrite(10, LOW);

and when use the D9 sheild, add this code:

digitalWrite(10, HIGH);
digitalWrite(9, LOW);

just have a try, if any question please contract me asap~

Hello loovee,

I am trying to stack a CAN-bus shield together with a WiFi Shield on an Arduino UNO R3. The thing is, they both use pin 10 for SS/CS. To start I am just trying with only my CAN-bus shield connected to the UNO and trying to get the communication working using another pin for the SS/CS than pin 10. On the Hardware side it is not a big problem, but I am a bit lost on the Software side.

You said that I should put the following in my code:

digitalWrite(10, HIGH);
digitalWrite(9, LOW);

But where exactly do I have to put this? And I do not really understand what this changes to the behavior of the SPI bus.

I thought I had to change “#define SPICS 10” into “#define SPICS 9” in the library file “mcp_can_dfs.h”. But after doing this it is not working anymore. If I reconnect it to pin 10, like it originally was, it also is not working anymore, which means the change is doing something,… but it seems that this is not enough to get pin 9 working as the SS/CS pin,…

I really need some help here

Thank you.