Re: A89: Turning LCD Off (and a lot more)


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Re: A89: Turning LCD Off (and a lot more)




Hi, it's me again :)
I got hold of Johan Borg now, and could ask him some questions.
according to him, the calc takes about 16-20mA when fully on.
If you turn off osc1 it takes 4-5mA, so the cpu and stuff is the most
powerhungry. of those 4-5mA most of it is the lcd.
So you will save about 25% on turning off the lcd with osc2.
He also said that $600015:1 (that you have tried) actually reduces most of the
power the lcd takes.
he also said that you can save some power by putting the contrast fully in one
endpoint (even with the lcd off), he didn't know right now, wich of them was
best though. And you could also save some by putting all the pins of the battery
detection (port $600000) high.
But that is not giving very much compared to turning off the lcd.

Details about battery detection and contrast can be found in 89hw.txt

he said there was a small chans that turning off osc2 affected the link port
logic, but he didn't think so. try it :)

//Olle

Olle Hedman wrote:
> 
> Just read your text a bit more closely. I guess you don't want to just wait for
> calls, but activly use the link port.
> Then just turn off the lcd&co. (osc 2).
> Then, if you somewhere needs to wait for something on the linkport, then maybe
> turn off osc1 too...
> 
> //Olle
> 
> Olle Hedman wrote:
> [a lot of crap ;)]


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