Working on programming AVR chips exposes a glaring omission in my
first design of the SPI Relay: not allowing multiple devices make
this task hard. I constantly have to unplug my SD card before, plug
the AVR chip holder, then play a bit, then unplug the AVR holder,
then replug the SD card...
My prototype for a SPI relay design is built, but I haven't tested
it yet. I need to adapt the code first, which is what I do here.
When the prototype is tested, I'll update the SDC recipe with a new
schema.
After having done my initial handshaking, I thought the rest of the
job was only a matter of implementing the protocol, but I was wrong.
There were many issues to fix before I could reliably communicate
with my 328P, mostly timing.
Now, I seem to be able to reliably extract fuse information, but
only in batch mode (that is, run "asp$ aspfl@" directly, then
running "(spid)" before running the next command). If I try to
interact with the chip in a single asp$ session, I sometimes get
wrong values (but no sync error! that's worrying...).
