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LPC210x - put an IO work as input

Started by JPCasainho July 3, 2009
Hello :-)

LPC210x do not have pullups or pulldowns, right?

If I want to use an IO for input, do I need put a pullup resistor on that IO or it juoust work without any pullup?

I am hacking a digital bathroom scale, for log my weight variations over time, on a memory SD Card. I want write the information on a comma separated values (CSV) file so then I can build a graph using OpenOffice.

I decided to wire the pins that went to LCD of original scale to my LPC2103, on an Olimex LC2103 header board. I am think in read all the segments lines for each backplane signal, to get the numbers written on original LCD. Does anyone have any experiency with this kind of LCD and want to give some ideas?

Please see more pictures of the prototype and info about the project here: http://code.google.com/p/casainho-projects/wiki/SdCardBathroomScale

An Engineer's Guide to the LPC2100 Series

Hi,

The pin will still work with / without any pull-up / pull-down. But you'll catch some noise as well as your extra input =) So, I guess, in short, most people would want external pull up / pull down on their GPIO.

Nice project anyway.

Regards,
-daniel

--- On Fri, 7/3/09, JPCasainho wrote:

From: JPCasainho
Subject: [lpc2000] LPC210x - put an IO work as input
To: l...
Date: Friday, July 3, 2009, 11:38 PM

Hello :-)

LPC210x do not have pullups or pulldowns, right?

If I want to use an IO for input, do I need put a pullup resistor on that IO or it juoust work without any pullup?

I am hacking a digital bathroom scale, for log my weight variations over time, on a memory SD Card. I want write the information on a comma separated values (CSV) file so then I can build a graph using OpenOffice.

I decided to wire the pins that went to LCD of original scale to my LPC2103, on an Olimex LC2103 header board. I am think in read all the segments lines for each backplane signal, to get the numbers written on original LCD. Does anyone have any experiency with this kind of LCD and want to give some ideas?

Please see more pictures of the prototype and info about the project here: http://code. google.com/ p/casainho- projects/ wiki/SdCardBathr oomScale

> The pin will still work with / without any pull-up / pull-down. But you'll catch some noise as well as your extra input =) So, I guess, in short, most people would want external pull up / pull down on their GPIO.

Thank you :-)

> Nice project anyway.

I need to control my weight, I am a electronics hacker and I take to much time in front of computer so I am a bit fat :-)

> Regards,
> -daniel

Oh, I name is Jorge Daniel :-) we share the same name :-)