Question
I am using the EVAL-AD7794/95EB board, and I can't setup a SPI communication
with using an STR9-EVAL board , I am using the external power supply (5V) LED
is ON (D1 is on when USB connected), I would like to know if ADC's SPI can be
used or if it is only for USB communication.
Answer
With the USB connection in place, the microcontroller on the eval board is
powered up and will 'talk' to the ADC.
To use the board as a stand-alone, an external power supply should be applied
to the board, the USB cable should be disconnected and the tracks from the
on-board micro to the ADC would need to be cut.
There are some test points on the board which allow the user to access the
serial interface lines.
However, the lines are presently connected to the microcontroller's interface.