Re: Multimedia keypad was Re: Someone asked about "nice" clock

["Paul Gordon" <paul_gordon@xxxxxxx>]

Hi Andy,

>
>
>The thing is, the VIOM is about the same price as a Basic stamp (or
>Atom - which is faster, and a bit cheaper) ... Even with my meagre
>electronics skills (skills  - lol) I can knock something up similar..
>So, for the momnet I'll skip that ... but it does look quite
>interesting ..
>

Fairy nuff, - I prefer an off-the-shelf solution for several reasons, -
mainly time, - I just don't have the time to learn new hardware/software
skills when a simple ready-to-run solution is already available for
"about
the same price". Secondly is the issue of support, - what happens if I
build
something myself, and it doesn't work? - £35 worth of components doing
nothing?


>Anyhow, rather than go entirely down the same route as you I've (last
>night) knocked up a very simple circuit and some connections. This
>gives me the same effect (tho it doesn't look as pretty as yours!)
>but with the ability to modify the way it works.
>

With Girder as the software element, the way it works is entirely dependent
on what I want to configure in Girder. - my buttons aren't hard-wired
directly to any input pins on a microcontroller, (well, they are I suppose
if you count the VIOM, but the software is off-board).


>As an example, for the switches - just for this test - I basically
>wired up 7 switches to 7 pins on the stamp. I'll change this so that
>only 3 pins on the stamp are used.. which gives me another 12 pins to
>play with (for example adding an LCD (or some flashing lights :P)
>
>I still can't get over how good yours looks, how blindingly simple
>the idea is and how effective the result!
>
>I havent looked at girder yet, I was looking at rolling my own.. but
>if girder takes away most of the hassle then it may be the best idea..
>
>I'm just wondering what input Girder will 'like' .. at the moment I
>send a single byte containing  the buttons pressed - ie if you
>convert it to binary you get a 1 if a switch is pressed and a 0 if
>not, but it can report more than one button being pressed at the same
>time.
>

The VIOM is configured to report switch status upon any input change, and
it
always reports the status of all the inputs at once, thus pressing button
number 1 will send "1000000000000000" to the serial port when
it's pressed,
and "0000000000000000" when it's released. It's therefore
possible to detect
more than 1 button being pressed simultaneously, and act upon that
combination.

Girder has a plug-in architecture, so you can add-in drivers for input from
many different devices. I'm using the generic serial port input/output
plugin. It took some fiddling with the options to get it to recognise the
input strings from the VIOM, as it has a bunch of options for converting
>from
only ever recognise the first string from the VIOM, and not any subsequent
ones... (I think there was some "stuff" left in the serial buffer
after the
first string...). Experimenting with some different values soon sorted that
out though...

The downside of course, is that a PC is required full-time, but as a PC is
providing the media feeds anyway, that's really not an issue for me... Plus
I'm going to try to put a watchdog in the VIOM that can reset the PC if it
hangs/crashes whatever.. - a recurring event on the PC will send a serial
port command to the VIOM to refresh one of it's internal timers, the VIOM
will have one of it's output lines connected to the PC's hardware reset
switch, and configured to close that output whenever the timer expires...

>all in all the hardest part of the project appears to be getting a
>nice faceplate and buttons!
>

Very true!


>Once again Paul - brilliant idea...
>

Thanks!


>Andy
>


Paul G.


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