Question
Is it possible to connect an external microcontroller to the EVAL-AD7734? If
so, how can I disable the internal ADuC824BS controller?
Answer
Two possible ways to implement external microcontroller communications are:
1. If you want to drive the on-board AD7734 from an external controller using
the MM74HC573, put on links LK28 and LK29. That would keep the ADuC824 in
download mode (to release the SPI bus) and enable the MM74HC573
buffers.
2. If you want to drive the on-board AD7734 from an external controller,
bypassing the MM74HC573, use position J3 to access the interface signals (you
can solder a standard 10-pin header there) and put on link LK28 to keep the
ADuC824 in download mode. Leave the LK29 open to keep the MM74HC573
disabled.