[TI-H] Re: PIXpander & Stuff


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[TI-H] Re: PIXpander & Stuff




if u get it working properly plz post ur new design
----- Original Message -----
From: "Winston" <gaylen@knology.net>
To: <ti-hardware@lists.ticalc.org>
Sent: Saturday, August 03, 2002 3:04 PM
Subject: [TI-H] PIXpander & Stuff


> Why not use a 6v camera battery regulated to 3.6v and use a voltage
doubler to get 7.2v? The camera batteries are supposed to be good for at
least a couple of hours and a backup or loading should only take a few
minutes.
> Just thinking....
> Winston
>
>
> *----------*
> Well, this is a rather late post compared to others who have made an
> attempt, but I have gotten fairly close to getting a heavily modified
> PIXpand design working properly. Unfortunately, it seems to be rather
> sensitive to battery levels, especially when communicating data to the
> TI. My last 9V just 'died' because its voltage kept dropping to 4.5V or
> less anytime the TI pulled one of the lines to ground, maybe I need a
> resistor there (I use 2 pins for the connection, with 18k pullup
> resistors).
>
> Also, I am looking into a proper solution for those using cards that
> require 7.2V like that ultra-mega-super-duper 96 page card that can hold
> a good 10+MB of data across those pages. Right now I am preferring a
> route that involves a 7.2V regulator and creating a tap line of
> resistors from 7.2V to Ground to power the PIC and the 3.6V line to the
> card. If someone has a better method to get 7.2V, 5V and 3.6V in the
> same circuit, tell me, as the tap method drains quite a bit of
> electricity, and the regulator is bad enough.
>
> I can talk to my TI-86 just fine while running of a AC->9V DC converter
> right now, and the PSX card I use for testing is still a little flakey,
> but I think I have a working PSX communication method within my grasp.
> (Talking at the full 250Khz too, which Sami's version doesn't do)
>
>
>
>




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