Problems MEGA2560+Ethernet Shield+CAN shield

Hello guys ! :slight_smile:

I’m working on a project which simulate several types of sensor outputs. This is managed beyond a REST API. But here is not the subject. :wink:

I want to send my datas on a CAN bus, so I’ve recently bought this CAN shield .

One point is that I don’t find the proper data sheet of this one. On the net, people mainly use the Sparkfun CAN shield. I just want to check the chip select, and the schematic. For example, I wonder what the two buttons on the top-right do.
I’m a bit lost :frowning: .

Another issue is the wiring. The ICSP module on the CAN shield doesn’t have pins to be plugged in.
Also, when I try to put the CAN shield above the Ethernet shield, the RJ45 plug stops the plugging of the CAN shield ( see photo as attachment).

Anyone would have a solution?

Thank you in advance !

The ICSP module on the CAN shield doesn't have pins to be plugged in.

Now, I wonder if I really need the SPI connection to send something on the CAN bus. In this way, I could use a serial command, couldn't I?