Yahoo Groups archive
Thread
2005-04-27 by dimed77
Hi, Does the LPC2138 P0.10 pin have special electrical specs.? When configured as GPIO, it goes to only 2V when in logic '1' output, no load. Tried with 2 different chips already. Could someone give me a hint? Thanks :) Di
2005-04-27 by tah2k
I saw the same thing when I was evaluating the 2138. I was told by the Phillips FAE to use external pull-ups when the I/O pin is configured as an output. The internal weak pull-up works fine when the I/O is configured as an input. --- In lpc2000@yahoogroups.com, "dimed77" <dimed77@y...> wrote:
> > Hi, > > Does the LPC2138 P0.10 pin have special electrical specs.? When > configured as GPIO, it goes to only 2V when in logic '1' output, no > load. Tried with 2 different chips already. > Could someone give me a hint? > > Thanks :) > > Di
2005-04-27 by Bill Knight
Ouch! -Bill On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote: I saw the same thing when I was evaluating the 2138. I was told by the Phillips FAE to use external pull-ups when the I/O pin is configured as an output. The internal weak pull-up works fine when the I/O is configured as an input. --- In lpc2000@yahoogroups.com, "dimed77" <dimed77@y...> wrote:
> > Hi, > > Does the LPC2138 P0.10 pin have special electrical specs.? When > configured as GPIO, it goes to only 2V when in logic '1' output, no > load. Tried with 2 different chips already. > Could someone give me a hint? > > Thanks :) > > Di
2005-04-27 by charlesgrenz
Do any of the other I/O lines that are configured as an Output exhibit the same problem or is it just that one (P0.10). I asked Philips in the beggining about the internal pull-ups for the 2138 and the response was as follows: " 1) pull-up resistors are in the 10s of K - We should have an exact value after analyzing process data. 2) Port 0 does have pull ups but note that i2c pins do not. " regards, Charles --- In lpc2000@yahoogroups.com, "Bill Knight" <BillK@t...> wrote:
> Ouch! > > -Bill > > > > On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote: > > I saw the same thing when I was evaluating the 2138. I was told by the > Phillips FAE to use external pull-ups when the I/O pin is configured > as an output. The internal weak pull-up works fine when the I/O is > configured as an input. > > > --- In lpc2000@yahoogroups.com, "dimed77" <dimed77@y...> wrote: > > > > Hi, > > > > Does the LPC2138 P0.10 pin have special electrical specs.? When > > configured as GPIO, it goes to only 2V when in logic '1' output, no > > load. Tried with 2 different chips already. > > Could someone give me a hint? > > > > Thanks :) > > > > Di
2005-04-27 by mfrazier@governors-america.com
The i2c pins must have external 10k pull ups added to work as GPIO correctly...this is not documented clearly at all!! Good Luck!! [Non-text portions of this message have been removed]
2005-04-27 by Lowry, Jeff
According to page 76-77 of the user manual P0.2, P0.3, P0.11, P0.14 are open drain outputs for i2c use. These need pullups when used as output because they will only pull low. FYI, All P1 pins have internal (~50k?) pullups if used as inputs. P0 pins do not. Jeff.
-----Original Message----- From: lpc2000@yahoogroups.com [mailto:lpc2000@yahoogroups.com] On Behalf Of mfrazier@... Sent: Wednesday, April 27, 2005 7:38 AM To: lpc2000@yahoogroups.com Subject: Re: [lpc2000] LPC2138 GPIO The i2c pins must have external 10k pull ups added to work as GPIO correctly...this is not documented clearly at all!! Good Luck!! [Non-text portions of this message have been removed] ________________________________ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/lpc2000/ * To unsubscribe from this group, send an email to: lpc2000-unsubscribe@yahoogroups.com <mailto:lpc2000-unsubscribe@yahoogroups.com?subject=Unsubscribe> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> . [Non-text portions of this message have been removed]
2005-04-27 by Diana Medeiros
Thanks guys, but now I realized there might be a problem with the power supply. I'll check all the I/O pins again, after this issue is solved. Di charlesgrenz <charles.grenz@...> wrote: Do any of the other I/O lines that are configured as an Output exhibit the same problem or is it just that one (P0.10). I asked Philips in the beggining about the internal pull-ups for the 2138 and the response was as follows: " 1) pull-up resistors are in the 10s of K - We should have an exact value after analyzing process data. 2) Port 0 does have pull ups but note that i2c pins do not. " regards, Charles --- In lpc2000@yahoogroups.com, "Bill Knight" <BillK@t...> wrote: > Ouch! > > -Bill > > > > On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote: > > I saw the same thing when I was evaluating the 2138. I was told by the > Phillips FAE to use external pull-ups when the I/O pin is configured > as an output. The internal weak pull-up works fine when the I/O is > configured as an input. > > > --- In lpc2000@yahoogroups.com, "dimed77" <dimed77@y...> wrote: > > > > Hi, > > > > Does the LPC2138 P0.10 pin have special electrical specs.? When > > configured as GPIO, it goes to only 2V when in logic '1' output, no > > load. Tried with 2 different chips already. > > Could someone give me a hint? > > > > Thanks :) > > > > Di --------------------------------- Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/lpc2000/ To unsubscribe from this group, send an email to: lpc2000-unsubscribe@yahoogroups.com Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com [Non-text portions of this message have been removed]
2005-04-28 by Bob Paddock
On Wednesday 27 April 2005 10:37 am, mfrazier@... wrote:
> The i2c pins must have external 10k pull ups added to work as GPIO
> correctly...this is not documented clearly at all!!
There is also the Linear Tech. LTC1694 - SMBus/I²C Accelerator
that may be used in place of the pull ups.
Improves SMBus Rise Time Transition
Ensures Data Integrity with Multiple Devices
on the SMBus
Improves Low State Noise Margin
Auto Detect Low Power Standby Mode
Wide Supply Voltage Range: 2.7V to 6V
Low Profile (1mm) SOT-23 (ThinSOT™)
http://www.linear.com/pc/productDetail.do?navId=H0,C1,C1007,C1070,P17102005-05-02 by Gus
I have just tested the P0.10 on my system and it is 3.3V!! I am using LPC2138 Did they fix the P0.10 issue on new chips? Thanks, Gus --- In lpc2000@yahoogroups.com, Diana Medeiros <dimed77@y...> wrote: > Thanks guys, but now I realized there might be a problem with the power supply. I'll check all the I/O pins again, after this issue is solved. > Di > charlesgrenz <charles.grenz@s...> wrote: > > Do any of the other I/O lines that are configured as an Output exhibit > the same problem or is it just that one (P0.10). > > I asked Philips in the beggining about the internal pull-ups for the > 2138 and the response was as follows: > > " > 1) pull-up resistors are in the 10s of K - We should have an exact > value after analyzing process data. > 2) Port 0 does have pull ups but note that i2c pins do not. > " > > regards, > Charles > > --- In lpc2000@yahoogroups.com, "Bill Knight" <BillK@t...> wrote: > > Ouch! > > > > -Bill > > > > > > > > On Wed, 27 Apr 2005 13:34:13 -0000, tah2k wrote: > > > > I saw the same thing when I was evaluating the 2138. I was told by the > > Phillips FAE to use external pull-ups when the I/O pin is configured > > as an output. The internal weak pull-up works fine when the I/O is > > configured as an input. > > > > > > --- In lpc2000@yahoogroups.com, "dimed77" <dimed77@y...> wrote: > > > > > > Hi, > > > > > > Does the LPC2138 P0.10 pin have special electrical specs.? When > > > configured as GPIO, it goes to only 2V when in logic '1' output, no > > > load. Tried with 2 different chips already. > > > Could someone give me a hint? > > > > > > Thanks :) > > > > > > Di > > > > > > --------------------------------- > Yahoo! Groups Links > > To visit your group on the web, go to: > http://groups.yahoo.com/group/lpc2000/ > > To unsubscribe from this group, send an email to: > lpc2000-unsubscribe@yahoogroups.com > > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
> > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > > [Non-text portions of this message have been removed]