Controlling multiple megabrite using SPI

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

I bought two megabrites to make some experiments. I'm using the sample code on megabrite [macetech documentation].

I have an arduino mega2560 and change the SPI ports:
SS -> 10 -> 53
MOSI -> 11 -> 51
MISO -> 12 -> 50
SCK -> 13 -> 52

If I plug only one megabrite, it works perfectly(both units are working for sure). But If I daisy chain, the primary works perfectly but the second no.

I'm plugging every output pin to the input on the second. Also I'm using a 7.5V wall adapter. The ground is connected to arduino the +vc no because of different voltages.

Do you have any idea why this is not working?

2

"The ground is connected to arduino the +vc no because of different voltages."

what exactly do you mean?

3
  • the ground of megabrite is plugged on ground of arduino.
  • the wall wart + is plugged on megabrite v+
4

I found the problem.

One of my megabrite is not passing signals correctly to the second. I inverted my megabrites and it works.

I'll talk to macetech!

Thanks,

Wagner