Re: [avrdude-dev] suggest a "programmer"?

[Nicholas Flowers]

>
> Regarding your multi-personality device


Have you spoken to my wife?  ;)

Interfaces: agreed.

Bridge interface:

ACM: requires 3 endpoints (2 data, and interrupt for line status).
Actually, as far as I understand the spec, the interrupt is supposed to be
optional, but the linux driver at least demands it.  The control commands
it uses are I think "class" commands, so wouldn't overlap with any vendor
commands.

FTDI: requires 2.  I don't love this interface (it puts 2 control
characters at the front of every data packet), but whatever.  Uses vendor
commands.


Programming interface:

USBtiny: requires 0 endpoints, but uses vendor commands (can't co-exist
with FTDI).

Atmel-like: require 2 endpoints, it looks like doesn't use control
interface at all (commands are sent over those two endpoints).



Combinations:

ACM/Tiny.  Might work, without code changes or multiple interfaces.  (I
think the ACM module selects based on interface, but the tiny will ignore
interfaces since it uses control anyway.)

ACM/Atmel: can't work (requires 5 endpoints, 16U2 only has 4)

FTDI/Tiny: can't work (control command overlap)

FTDI/Atmel: might work, but requires (as you say) enough support in avrdude
to select the endpoints based on interface.  (Which presumably means
changes to the config parser, as well?)