Re: [lcd4linux] GPO circuitry

[Martin H. <ma...@he...>]

Hi Michael,

Michael Reinelt wrote:
>>> Is the LED's brightness proportional to the current?  Not sure
>>> myself...
>> No, it isn't - at least not on the displays I have here.
> Oh, I think it is. It has to be. Brightness is proportional to power. 
> Power is proportional to the current.
> 
> Maybe you meant that it's not linear - that may be true.
Well, at least on the one display (manufactured by display-electronic)
it's all but proportional (let alone linear). It's either on (at a
constant brightness) or off (that is, using 5V as defined in the specs).

The other display I have is from Crystalfontz, and that one is the one
with the two levels of brightness - and this one 'jumps' from off to the
first brighness level to the second brightness level as the resistance
is lowered. Maybe it's just these two displays, and others work more
like you would expect.

Oh, and no, the power supply used for this has plenty of Amps to spare
(the backlight uses around 150mA at 5V, and the power supply is rated at
5V/1.25A)

> btw, Martin, I'd be very interested in your opinion regarding the 
> 'dynamic loading of plugins'.
I haven't forgotten about that - I have it on my todo-list. But in order
to give you a meaningful response, I'll need to research a bit, if my
thoughts on that topic are actually correct (all of my experience with
writing plugins and such are from Windows - not much use for lcd4linux).

Martin