RE: New Monitor: Spot Killer & microprocessor issues

> Clay, do you still want a micro on board?
>
Well, it's certainly not required. But it does fall into my "gee-wiz that
would be neat" category. ;-)

> If so we need to hash
> out what exactly it will do. The amp has a shutdown (mute) mode
> that could be activated if we had a good reason to use it. Let's
> re-iterate the microprocessor function again.
>
Ok. I can think of a variety of functions that would be nice and are handy
to implement on a microcontroller. (The AVR's have onboard EEPROM which is
kinda slick...)

1) smart and/or adjustable spot killer with variable stages of shutdown
(guns off, defl. amp off, power off)
2) smart diagnostics (display quadrant of failure-- probably most pertinent
to discrete designs)
3) Time in use/time since service (hour meter saved in EEPROM)
4) Temperature monitoring (use LM75 or something)
5) Fan control/additional cooling (either PWM or just a 2N7000 to click on a
fan)
6) soft size/center control & front-panel controls (digital potentiometers
on input op-amps)
7) presets for size/center (once again by EEPROM settings)
8) "Vertical in Horizontal" mode (digital pots automatically adjust display
to a vertical aspect ratio on a horizontal monitor-- good for Tempest on
Major Havoc or Tac/Scan in a StarTrek).
9) test display? (draw an "X" or something on the screen with a couple caps
or PWM D/A?)

> I am a little
> concerned about the support it will require in terms of buffering,
> power supply, crystal, and cost increment.
>
I'll be a few bucks for sure. Depends on functionality required/desired.

> On the other hand,
> it could be made to be a solder-in option or better yet, a daughtercard
> like you are famous for could offload all of this functionality
> to a second design!
>
That's a good idea. I agree that it might not be smart to burden the base
design with the smart-functions. On the other hand, I think it would be fun
to make the add-on available as an upgrade for extra functions... I could
do a couple different versions too-- one that's "supervisor only"
(spotkiller, temp monitor, time-meter) and one that has a remote-control
board for screen adjustments from the front panel, BIST, etc.)

> The daughtercard sounds viable, if we can
> agree on a good cheap and physically stable thus reliable connector
> to use for it.
>
In the case of the microcontroller controlled size and center controls I'd
need to be able to intercept the input signals. Depending on the desired
feature-set of the supervisor board we might just look at something like a
16 pin? (2x8) .1" header ($0.15-0.20?). In the "default" configuration,
ship with shunts that just connect the signals across the connector-- to use
the daughtercard remove the shunts and plug in the daughtercard:

x-in --o o-- x-out
y-in --o o-- y-out
r-in --o o-- r-out
g-in --o o-- g-out
b-in --o o-- b-out
+v --o o-- +v
gnd --o o-- gnd
-v --o o-- -v

Any buttons, fan connectors, temperature sensores, etc. could be on another
connector on the daughtercard that goes to a remote control panel that you
could mount behind the coin-door or someplace easily accessable. (Since
I've got digital pots on the daughtercard the "remote control" board is only
digital so we don't have to worry about picking up noise or attenuating the
analog signals with a bunch of wiring...)

The shunts across the +v, -v, and gnd wouldn't be needed, but probably
should be included just for the sake of consistency.

I'd even pay for the connectors and shunts-- in order to be able to do a
daughtercard for it later. ;-)

-Clay
Received on Tue Nov 9 18:26:18 1999