Newbie questions

[Mercoory]

Dear harryberlin, forum members,

After a long planning, yesterday, I successfully got an MCP2025 chip and an Arduino Mega 2560.
The first thing, was to upload harryberlin's IBUS Hex file to the MEGA (Rel:181024).
I hooked everything, but the car, doesn't seem to see the MEGA.

I've searched a lot for these question, but with no luck.

So , my question are :
- The MEGA uses the same PIN's with the .hex : D8,D9,D13 ?
- Is it safe to connect the MEGA to the car via the MCP2025 AND with USB to the computer ?
- Is it okay that the MCP2025 is powered via PIN1,PIN3 ( CAR 12V ), that on PIN4 (LBus / IBus ) there is 12V too? ( Measured via Multimeter )

Thanks, for your answers!

P.S.: Sorry, for the noob questions