[Opendispense] UI design

Nick Bannon nick@ucc.gu.uwa.edu.au
Thu Aug 7 16:41:15 2003


On Thu, Aug 07, 2003 at 11:11:17PM +0800, Bernard Blackham wrote:
[...]
> I was thinking of assigning them 50 - 56. But always changable.

Ah, but the columns are labelled first, so 5x codes are in use (but
not x5).

[...]
> Hmmmm, if we limit withdrawls to $1 a time, and at most $3 a day (or
> something) I think it's convenience would outweight the security
> issues.

True. It'd be nice to have a bus ticket's worth of change to hand.
We'd have to refill the change often, or it'll spent its time showing
"EXACT CHANGE ONLY (OR COKECREDIT)" . ::-)

[...]
> What I am rethinking though, is taking wimpier ways out - to allow
> the interface to be as flexible as possible, make the vending
> machine as dumb as possible (just a display, keypad, set of motors
> and coin mech), and have the interface driven from mermaid. Hence
> keypresses would travel to mermaid and display updates back to the
> machine.

Good idea. That's definitely a good milestone if nothing else - that
functionality is necessary and sufficient, if not exhaustive.

> It might seem a little laggy even over a 9600bps link, but
> this way we only need to flash the ROM as few times as possible.

9600bps is ten times what we'd need - if it's laggy, we're doing it
wrong. "Wrong" includes, for example, using SOAP to interface with the
thing. ::-)

Nick.

-- 
   Nick Bannon   | "I made this letter longer than usual because
nick-sig@rcpt.to | I lack the time to make it shorter." - Pascal