Lpc2000

Aye having just applied a couple of 2k2 resistors to pull the signals up on
the board they both work fine. All the inputs are pulled low atm.
Now I simply have to slap our resident hardware engineer for not putting the
input of our front panel switch on an IRQ line.

Cheers for the quick reply.

Andy

-----Original Message-----
From: lpc2000@yahoogroups.com [mailto:lpc2000@yahoogroups.com]On Behalf
Of c.barbaro
Sent: 03 March 2006 15:39
To: lpc2000@yahoogroups.com
Subject: [lpc2000] Re: LPC2129 GPIO issues with P0.2 and P0.4


--- In lpc2000@yahoogroups.com, "Andrew Berney" <amb@...> wrote:
>
> Currently there are no pull ups on either P0.2 or P0.3... we're not
using
> I2C but I'm guessing they're still required even for GPIO use.
>

You have to put pullups on each pin that can be used with I2C since
these pins are open collector.
I found a similar problem using LPC2138 (it has 2 I2C units so there
are 4 open collector pins).
Effectively this is written in VERY small character in the pin
configuration section of user manual.
Regarding other pins you have to pull them (to gnd or vcc) if they are
programmed as inputs, to avoid a floating voltage.

Carlo Barbaro







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