[TI-H] Re: Calc Port Voltage


[Prev][Next][Index][Thread]

[TI-H] Re: Calc Port Voltage




What method were you using to step-up the voltage to the calc?  This
shouldn't cause much delay.  You should be able to make a simple
transistor circuit to connect a 5V calc line to a 3.3V IC.  Let me know
what your current method is.

-----Original Message-----
From: ti-hardware-bounce@lists.ticalc.org
[mailto:ti-hardware-bounce@lists.ticalc.org] On Behalf Of Shyam
Dwaraknath
Sent: Saturday, August 17, 2002 8:03 PM
To: ti-hardware@lists.ticalc.org
Subject: [TI-H] Re: Calc Port Voltage 


The Atmega8L use one power supply that goes to both the IO and CPU. If
it runs at 5V the Xe1202 to cant work with it. If I step the voltage
down for the chip I need a way to step it calc up to the 5v to send to
the calc. this causes a noticeable lag in the transmission for a
9.6kbaud connection. Uggh, I am just thinking about using a PIC even
though I don't have a Programmer for it.


On Friday, August 16, 2002, at 10:59 AM, Shyam Dwaraknath wrote:

> Oh yeah this is for a Radio link project that i am trying to make. I
> found a great chip from Xemics for around $10. Its called Xe1202. The
> site is www.xemics.com <http://www.xemics.com/> . It uses a 3V Supply
an
> I wanted to use microcontroller with a good amount of Sram and an SPI
so
> it could program the Xe1202. That's why I choose the Atmega8L. I need
to
> Interface the Atmega8L to the link port. But I don't want to use 5V
for
> the Supply cause its use way too much current? Instead I wanted to use
> 3V. If you have any suggestion please comment.

You could always step the supply voltage down to 3V for the chip, the 
PIXpander uses a 2 resistor voltage divider for the 3.3V required for 
the memory card. It does work.






Follow-Ups: References: