Re: [lcd4linux] GPO circuitry

[Michael R. <re...@eu...>]

Hi Martin,


>> Oh, I think it is. It has to be. Brightness is proportional to power. 
>> Power is proportional to the current.

> 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).

Strange. I can't imagine how this should work. Maybe there's some 
additional components on the display - something like a current sink?

> 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)

Oh! I'd never spend so much current to my displays (I destroyed three of 
them in the meantime :-( That's why I spent the last months soldering a 
power supply with current limiting. No more buning chips....
It's a quite cool device - a step-down regulator (switching power 
supply) that delivers from 0 to 14 V, 0-6 ampere, and can be supplied by 
a car battery (i.e. it needs only +12V-+14V). Especially the absence of 
a symmetric supply voltage made things quite complex. (I need this for 
my model aircrafts, because you don't have 220V out there in the fields).

Oh... this is getting a bit off-topic :-)


>> 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).

Well, I'm not expecting too deep experience - just your comments on my 
and Xavier's arguments....

OTOH, I'm planning to think about this stuff when the NextGeneration has 
settled down a bit, and at least a 0.9.12 is released.


-- 
Michael Reinelt                                   Tel: +43 676 3079941
Geisslergasse 4                                   Fax: +43 316  692343
A-8045 Graz, Austria                          e-mail: re...@eu...