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Discussion Groups | LPC900 | Problems communicating with 89LPC935 on my own circuit (schematic included)
Find help, specifications and source code for the LPC900. The LPC900 challenges Microchip and AVR based on the worlds most popular 8-bit architecture the 80C51. With a 2-clock core the LPC900 series is a high performance, very flexible and low cost 8-bit microcontroller family. Designers using or interested in these devices are encouraged to share their know-how and ask questions.
Problems communicating with 89LPC935 on my own circuit (schematic included) - bradziegler - Dec 11 17:46:38 2006
I've been working with a hardware design for my own evaluation board of
sorts that has 8 LEDs, a
couple of DIP switches, pushbuttons, etc.... The circuit is based on
the MCB900 schematic,
which I got from http://www.keil.com/mcb900/mcb900-schematics.pdf
I used a simple LED flasher program to test whether or not the circuit
is working currently and on both the MCB900 and
my board, they both flash just fine. When I use FlashMagic and my
MCB900 board, the chip
communicates just fine. However, if I use my board design and
FlashMagic, I can't get it to communicate at all.
The schematic to my board is below.
I've been playing with this circuit for a couple of weeks looking at
everything and I just can't figure out what is the
problem. Would anyone have any suggestions or maybe spot something I
don't? Thanks.....
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - Pramod - Dec 12 1:04:26 2006
You have a 7402 in the schematic, if it's the same on-board then you
ought to change it to a LV family.
BR
Pramod
--- In l...@yahoogroups.com, "bradziegler"
wrote:
> I've been working with a hardware design for my own evaluation board of
> sorts that has 8 LEDs, a
> couple of DIP switches, pushbuttons, etc.... The circuit is based on
> the MCB900 schematic,
> which I got from http://www.keil.com/mcb900/mcb900-schematics.pdf
> .
>
> I used a simple LED flasher program to test whether or not the circuit
> is working currently and on both the MCB900 and
> my board, they both flash just fine. When I use FlashMagic and my
> MCB900 board, the chip
> communicates just fine. However, if I use my board design and
> FlashMagic, I can't get it to communicate at all.
>
> The schematic to my board is below.
>
> I've been playing with this circuit for a couple of weeks looking at
> everything and I just can't figure out what is the
> problem. Would anyone have any suggestions or maybe spot something I
> don't? Thanks.....
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
ought to change it to a LV family.
BR
Pramod
--- In l...@yahoogroups.com, "bradziegler"
wrote:
> I've been working with a hardware design for my own evaluation board of
> sorts that has 8 LEDs, a
> couple of DIP switches, pushbuttons, etc.... The circuit is based on
> the MCB900 schematic,
> which I got from http://www.keil.com/mcb900/mcb900-schematics.pdf
>
>
> I used a simple LED flasher program to test whether or not the circuit
> is working currently and on both the MCB900 and
> my board, they both flash just fine. When I use FlashMagic and my
> MCB900 board, the chip
> communicates just fine. However, if I use my board design and
> FlashMagic, I can't get it to communicate at all.
>
> The schematic to my board is below.
>
> I've been playing with this circuit for a couple of weeks looking at
> everything and I just can't figure out what is the
> problem. Would anyone have any suggestions or maybe spot something I
> don't? Thanks.....
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - bradziegler - Dec 12 13:46:56 2006
What would be the functional difference in using an LV-series versus a
HC/HCT-series IC, other than low voltage in the LV case? After
checking this with what I have, I used a 74HC02 instead of a 74HCT02,
as used on the MCB900 board. Would this cause problems?
--- In l...@yahoogroups.com, "Pramod" wrote:
>
> You have a 7402 in the schematic, if it's the same on-board then you
> ought to change it to a LV family.
> BR
> Pramod
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> >
> > I've been working with a hardware design for my own evaluation
board of
> > sorts that has 8 LEDs, a
> > couple of DIP switches, pushbuttons, etc.... The circuit is based
on
> > the MCB900 schematic,
> > which I got from http://www.keil.com/mcb900/mcb900-schematics.pdf
> > .
> >
> > I used a simple LED flasher program to test whether or not the
circuit
> > is working currently and on both the MCB900 and
> > my board, they both flash just fine. When I use FlashMagic and my
> > MCB900 board, the chip
> > communicates just fine. However, if I use my board design and
> > FlashMagic, I can't get it to communicate at all.
> >
> > The schematic to my board is below.
> >
> > I've been playing with this circuit for a couple of weeks looking
at
> > everything and I just can't figure out what is the
> > problem. Would anyone have any suggestions or maybe spot
something I
> > don't? Thanks.....
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
HC/HCT-series IC, other than low voltage in the LV case? After
checking this with what I have, I used a 74HC02 instead of a 74HCT02,
as used on the MCB900 board. Would this cause problems?
--- In l...@yahoogroups.com, "Pramod"
>
> You have a 7402 in the schematic, if it's the same on-board then you
> ought to change it to a LV family.
> BR
> Pramod
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> >
> > I've been working with a hardware design for my own evaluation
board of
> > sorts that has 8 LEDs, a
> > couple of DIP switches, pushbuttons, etc.... The circuit is based
on
> > the MCB900 schematic,
> > which I got from http://www.keil.com/mcb900/mcb900-schematics.pdf
> >
> >
> > I used a simple LED flasher program to test whether or not the
circuit
> > is working currently and on both the MCB900 and
> > my board, they both flash just fine. When I use FlashMagic and my
> > MCB900 board, the chip
> > communicates just fine. However, if I use my board design and
> > FlashMagic, I can't get it to communicate at all.
> >
> > The schematic to my board is below.
> >
> > I've been playing with this circuit for a couple of weeks looking
at
> > everything and I just can't figure out what is the
> > problem. Would anyone have any suggestions or maybe spot
something I
> > don't? Thanks.....
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - Pramod - Dec 13 1:26:45 2006
1. In your case you have a working circuit to compare -- then why not
use the same parts / families.
You could refer to the Philips App Note -- Interfacing 3V and 5V
applications AN240.
2. You could bypass the functionality of the 02 logic, and instead opt
for the 'break-detect' supported by the LPC.
BR
Pramod
--- In l...@yahoogroups.com, "bradziegler"
wrote:
>
> What would be the functional difference in using an LV-series versus a
> HC/HCT-series IC, other than low voltage in the LV case? After
> checking this with what I have, I used a 74HC02 instead of a 74HCT02,
> as used on the MCB900 board. Would this cause problems?
>
> --- In l...@yahoogroups.com, "Pramod" wrote:
> >
> > You have a 7402 in the schematic, if it's the same on-board then you
> > ought to change it to a LV family.
> > BR
> > Pramod
> > --- In l...@yahoogroups.com, "bradziegler"
> > wrote:
> > >
> > >
> > > I've been working with a hardware design for my own evaluation
> board of
> > > sorts that has 8 LEDs, a
> > > couple of DIP switches, pushbuttons, etc.... The circuit is based
> on
> > > the MCB900 schematic,
> > > which I got from http://www.keil.com/mcb900/mcb900-schematics.pdf
> > > .
> > >
> > > I used a simple LED flasher program to test whether or not the
> circuit
> > > is working currently and on both the MCB900 and
> > > my board, they both flash just fine. When I use FlashMagic and my
> > > MCB900 board, the chip
> > > communicates just fine. However, if I use my board design and
> > > FlashMagic, I can't get it to communicate at all.
> > >
> > > The schematic to my board is below.
> > >
> > > I've been playing with this circuit for a couple of weeks looking
> at
> > > everything and I just can't figure out what is the
> > > problem. Would anyone have any suggestions or maybe spot
> something I
> > > don't? Thanks.....
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
use the same parts / families.
You could refer to the Philips App Note -- Interfacing 3V and 5V
applications AN240.
2. You could bypass the functionality of the 02 logic, and instead opt
for the 'break-detect' supported by the LPC.
BR
Pramod
--- In l...@yahoogroups.com, "bradziegler"
wrote:
>
> What would be the functional difference in using an LV-series versus a
> HC/HCT-series IC, other than low voltage in the LV case? After
> checking this with what I have, I used a 74HC02 instead of a 74HCT02,
> as used on the MCB900 board. Would this cause problems?
>
> --- In l...@yahoogroups.com, "Pramod"
> >
> > You have a 7402 in the schematic, if it's the same on-board then you
> > ought to change it to a LV family.
> > BR
> > Pramod
> > --- In l...@yahoogroups.com, "bradziegler"
> > wrote:
> > >
> > >
> > > I've been working with a hardware design for my own evaluation
> board of
> > > sorts that has 8 LEDs, a
> > > couple of DIP switches, pushbuttons, etc.... The circuit is based
> on
> > > the MCB900 schematic,
> > > which I got from http://www.keil.com/mcb900/mcb900-schematics.pdf
> > >
> > >
> > > I used a simple LED flasher program to test whether or not the
> circuit
> > > is working currently and on both the MCB900 and
> > > my board, they both flash just fine. When I use FlashMagic and my
> > > MCB900 board, the chip
> > > communicates just fine. However, if I use my board design and
> > > FlashMagic, I can't get it to communicate at all.
> > >
> > > The schematic to my board is below.
> > >
> > > I've been playing with this circuit for a couple of weeks looking
> at
> > > everything and I just can't figure out what is the
> > > problem. Would anyone have any suggestions or maybe spot
> something I
> > > don't? Thanks.....
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - bradziegler - Dec 13 9:17:55 2006
In reality, I have used the same part families. My board uses a
MAX3223 instead of a MAX3221 (since the 3221 is not available as a
DIP). The only other difference is a 74HC02 instead of a 74HCT02
(which I swapped out last night and did not change anything).....
I'll probably keep playing with this some. Fustrating....
--- In l...@yahoogroups.com, "Pramod" wrote:
>
> 1. In your case you have a working circuit to compare -- then why
not
> use the same parts / families.
> You could refer to the Philips App Note -- Interfacing 3V and 5V
> applications AN240.
>
> 2. You could bypass the functionality of the 02 logic, and instead
opt
> for the 'break-detect' supported by the LPC.
>
> BR
> Pramod
>
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> > What would be the functional difference in using an LV-series
versus a
> > HC/HCT-series IC, other than low voltage in the LV case? After
> > checking this with what I have, I used a 74HC02 instead of a
74HCT02,
> > as used on the MCB900 board. Would this cause problems?
> >
> > --- In l...@yahoogroups.com, "Pramod" wrote:
> > >
> > > You have a 7402 in the schematic, if it's the same on-board
then you
> > > ought to change it to a LV family.
> > > BR
> > > Pramod
> > > --- In l...@yahoogroups.com, "bradziegler"
> > > wrote:
> > > >
> > > >
> > > > I've been working with a hardware design for my own
evaluation
> > board of
> > > > sorts that has 8 LEDs, a
> > > > couple of DIP switches, pushbuttons, etc.... The circuit is
based
> > on
> > > > the MCB900 schematic,
> > > > which I got from http://www.keil.com/mcb900/mcb900-
schematics.pdf
> > > > .
> > > >
> > > > I used a simple LED flasher program to test whether or not
the
> > circuit
> > > > is working currently and on both the MCB900 and
> > > > my board, they both flash just fine. When I use FlashMagic
and my
> > > > MCB900 board, the chip
> > > > communicates just fine. However, if I use my board design
and
> > > > FlashMagic, I can't get it to communicate at all.
> > > >
> > > > The schematic to my board is below.
> > > >
> > > > I've been playing with this circuit for a couple of weeks
looking
> > at
> > > > everything and I just can't figure out what is the
> > > > problem. Would anyone have any suggestions or maybe spot
> > something I
> > > > don't? Thanks.....
> > > >
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
MAX3223 instead of a MAX3221 (since the 3221 is not available as a
DIP). The only other difference is a 74HC02 instead of a 74HCT02
(which I swapped out last night and did not change anything).....
I'll probably keep playing with this some. Fustrating....
--- In l...@yahoogroups.com, "Pramod"
>
> 1. In your case you have a working circuit to compare -- then why
not
> use the same parts / families.
> You could refer to the Philips App Note -- Interfacing 3V and 5V
> applications AN240.
>
> 2. You could bypass the functionality of the 02 logic, and instead
opt
> for the 'break-detect' supported by the LPC.
>
> BR
> Pramod
>
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> > What would be the functional difference in using an LV-series
versus a
> > HC/HCT-series IC, other than low voltage in the LV case? After
> > checking this with what I have, I used a 74HC02 instead of a
74HCT02,
> > as used on the MCB900 board. Would this cause problems?
> >
> > --- In l...@yahoogroups.com, "Pramod"
> > >
> > > You have a 7402 in the schematic, if it's the same on-board
then you
> > > ought to change it to a LV family.
> > > BR
> > > Pramod
> > > --- In l...@yahoogroups.com, "bradziegler"
> > > wrote:
> > > >
> > > >
> > > > I've been working with a hardware design for my own
evaluation
> > board of
> > > > sorts that has 8 LEDs, a
> > > > couple of DIP switches, pushbuttons, etc.... The circuit is
based
> > on
> > > > the MCB900 schematic,
> > > > which I got from http://www.keil.com/mcb900/mcb900-
schematics.pdf
> > > >
> > > >
> > > > I used a simple LED flasher program to test whether or not
the
> > circuit
> > > > is working currently and on both the MCB900 and
> > > > my board, they both flash just fine. When I use FlashMagic
and my
> > > > MCB900 board, the chip
> > > > communicates just fine. However, if I use my board design
and
> > > > FlashMagic, I can't get it to communicate at all.
> > > >
> > > > The schematic to my board is below.
> > > >
> > > > I've been playing with this circuit for a couple of weeks
looking
> > at
> > > > everything and I just can't figure out what is the
> > > > problem. Would anyone have any suggestions or maybe spot
> > something I
> > > > don't? Thanks.....
> > > >
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - lorcan - Dec 13 10:36:01 2006
Hi
This may be a red herring, but we have had problems in the past with RS232 chips when the charge pump capacitors are too small. I think it was the Maxim devices that had A and B versions and one couldn't pump the out voltages high enough with the lower value caps - you can see the output voltage saw-toothing at too low a level, using a 'scope
Cheers
Lorcan
================================
SEEC Ltd
22 Newton Court
Haywards Heath
West Sussex
RH16 3BL
Tel.: 07951 467019
================================
----- Original Message -----
From: bradziegler
To: l...@yahoogroups.com
Sent: Wednesday, December 13, 2006 2:15 PM
Subject: [lpc900_users] Re: Problems communicating with 89LPC935 on my own circuit (schematic included)
In reality, I have used the same part families. My board uses a
MAX3223 instead of a MAX3221 (since the 3221 is not available as a
DIP). The only other difference is a 74HC02 instead of a 74HCT02
(which I swapped out last night and did not change anything).....
I'll probably keep playing with this some. Fustrating....
--- In l...@yahoogroups.com, "Pramod" wrote:
>
> 1. In your case you have a working circuit to compare -- then why
not
> use the same parts / families.
> You could refer to the Philips App Note -- Interfacing 3V and 5V
> applications AN240.
>
> 2. You could bypass the functionality of the 02 logic, and instead
opt
> for the 'break-detect' supported by the LPC.
>
> BR
> Pramod
>
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> > What would be the functional difference in using an LV-series
versus a
> > HC/HCT-series IC, other than low voltage in the LV case? After
> > checking this with what I have, I used a 74HC02 instead of a
74HCT02,
> > as used on the MCB900 board. Would this cause problems?
> >
> > --- In l...@yahoogroups.com, "Pramod" wrote:
> > >
> > > You have a 7402 in the schematic, if it's the same on-board
then you
> > > ought to change it to a LV family.
> > > BR
> > > Pramod
> > > --- In l...@yahoogroups.com, "bradziegler"
> > > wrote:
> > > >
> > > >
> > > > I've been working with a hardware design for my own
evaluation
> > board of
> > > > sorts that has 8 LEDs, a
> > > > couple of DIP switches, pushbuttons, etc.... The circuit is
based
> > on
> > > > the MCB900 schematic,
> > > > which I got from http://www.keil.com/mcb900/mcb900-
schematics.pdf
> > > > .
> > > >
> > > > I used a simple LED flasher program to test whether or not
the
> > circuit
> > > > is working currently and on both the MCB900 and
> > > > my board, they both flash just fine. When I use FlashMagic
and my
> > > > MCB900 board, the chip
> > > > communicates just fine. However, if I use my board design
and
> > > > FlashMagic, I can't get it to communicate at all.
> > > >
> > > > The schematic to my board is below.
> > > >
> > > > I've been playing with this circuit for a couple of weeks
looking
> > at
> > > > everything and I just can't figure out what is the
> > > > problem. Would anyone have any suggestions or maybe spot
> > something I
> > > > don't? Thanks.....
> > > >
> > >
> >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
This may be a red herring, but we have had problems in the past with RS232 chips when the charge pump capacitors are too small. I think it was the Maxim devices that had A and B versions and one couldn't pump the out voltages high enough with the lower value caps - you can see the output voltage saw-toothing at too low a level, using a 'scope
Cheers
Lorcan
================================
SEEC Ltd
22 Newton Court
Haywards Heath
West Sussex
RH16 3BL
Tel.: 07951 467019
================================
----- Original Message -----
From: bradziegler
To: l...@yahoogroups.com
Sent: Wednesday, December 13, 2006 2:15 PM
Subject: [lpc900_users] Re: Problems communicating with 89LPC935 on my own circuit (schematic included)
In reality, I have used the same part families. My board uses a
MAX3223 instead of a MAX3221 (since the 3221 is not available as a
DIP). The only other difference is a 74HC02 instead of a 74HCT02
(which I swapped out last night and did not change anything).....
I'll probably keep playing with this some. Fustrating....
--- In l...@yahoogroups.com, "Pramod"
>
> 1. In your case you have a working circuit to compare -- then why
not
> use the same parts / families.
> You could refer to the Philips App Note -- Interfacing 3V and 5V
> applications AN240.
>
> 2. You could bypass the functionality of the 02 logic, and instead
opt
> for the 'break-detect' supported by the LPC.
>
> BR
> Pramod
>
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> > What would be the functional difference in using an LV-series
versus a
> > HC/HCT-series IC, other than low voltage in the LV case? After
> > checking this with what I have, I used a 74HC02 instead of a
74HCT02,
> > as used on the MCB900 board. Would this cause problems?
> >
> > --- In l...@yahoogroups.com, "Pramod"
> > >
> > > You have a 7402 in the schematic, if it's the same on-board
then you
> > > ought to change it to a LV family.
> > > BR
> > > Pramod
> > > --- In l...@yahoogroups.com, "bradziegler"
> > > wrote:
> > > >
> > > >
> > > > I've been working with a hardware design for my own
evaluation
> > board of
> > > > sorts that has 8 LEDs, a
> > > > couple of DIP switches, pushbuttons, etc.... The circuit is
based
> > on
> > > > the MCB900 schematic,
> > > > which I got from http://www.keil.com/mcb900/mcb900-
schematics.pdf
> > > >
> > > >
> > > > I used a simple LED flasher program to test whether or not
the
> > circuit
> > > > is working currently and on both the MCB900 and
> > > > my board, they both flash just fine. When I use FlashMagic
and my
> > > > MCB900 board, the chip
> > > > communicates just fine. However, if I use my board design
and
> > > > FlashMagic, I can't get it to communicate at all.
> > > >
> > > > The schematic to my board is below.
> > > >
> > > > I've been playing with this circuit for a couple of weeks
looking
> > at
> > > > everything and I just can't figure out what is the
> > > > problem. Would anyone have any suggestions or maybe spot
> > something I
> > > > don't? Thanks.....
> > > >
> > >
> >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - Nilesh - Dec 14 0:41:53 2006
Yes exactly right. We have also faced such problem with MAX3221.
First we are using with P89LPC932 at that time we are using 100nF
Capacitor but after release of P89LPC932A1 we have to use 200nF .
This just for proper de-coupling between Vdd and GND.
Internal RC Oscillator is not stable so Proper de-coupling is requird for
proper communication.
Nilesh
lorcan wrote:
Hi
This may be a red herring, but we have had problems in the past with RS232 chips when the charge pump capacitors are too small. I think it was the Maxim devices that had A and B versions and one couldn't pump the out voltages high enough with the lower value caps - you can see the output voltage saw-toothing at too low a level, using a 'scope
Cheers
Lorcan
================================
SEEC Ltd
22 Newton Court
Haywards Heath
West Sussex
RH16 3BL
Tel.: 07951 467019
================================
----- Original Message -----
From: bradziegler
To: l...@yahoogroups.com
Sent: Wednesday, December 13, 2006 2:15 PM
Subject: [lpc900_users] Re: Problems communicating with 89LPC935 on my own circuit (schematic included)
In reality, I have used the same part families. My board uses a
MAX3223 instead of a MAX3221 (since the 3221 is not available as a
DIP). The only other difference is a 74HC02 instead of a 74HCT02
(which I swapped out last night and did not change anything).....
I'll probably keep playing with this some. Fustrating....
--- In l...@yahoogroups.com, "Pramod" wrote:
>
> 1. In your case you have a working circuit to compare -- then why
not
> use the same parts / families.
> You could refer to the Philips App Note -- Interfacing 3V and 5V
> applications AN240.
>
> 2. You could bypass the functionality of the 02 logic, and instead
opt
> for the 'break-detect' supported by the LPC.
>
> BR
> Pramod
>
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> > What would be the functional difference in using an LV-series
versus a
> > HC/HCT-series IC, other than low voltage in the LV case? After
> > checking this with what I have, I used a 74HC02 instead of a
74HCT02,
> > as used on the MCB900 board. Would this cause problems?
> >
> > --- In l...@yahoogroups.com, "Pramod" wrote:
> > >
> > > You have a 7402 in the schematic, if it's the same on-board
then you
> > > ought to change it to a LV family.
> > > BR
> > > Pramod
> > > --- In l...@yahoogroups.com, "bradziegler"
> > > wrote:
> > > >
> > > >
> > > > I've been working with a hardware design for my own
evaluation
> > board of
> > > > sorts that has 8 LEDs, a
> > > > couple of DIP switches, pushbuttons, etc.... The circuit is
based
> > on
> > > > the MCB900 schematic,
> > > > which I got from http://www.keil.com/mcb900/mcb900-
schematics.pdf
> > > > .
> > > >
> > > > I used a simple LED flasher program to test whether or not
the
> > circuit
> > > > is working currently and on both the MCB900 and
> > > > my board, they both flash just fine. When I use FlashMagic
and my
> > > > MCB900 board, the chip
> > > > communicates just fine. However, if I use my board design
and
> > > > FlashMagic, I can't get it to communicate at all.
> > > >
> > > > The schematic to my board is below.
> > > >
> > > > I've been playing with this circuit for a couple of weeks
looking
> > at
> > > > everything and I just can't figure out what is the
> > > > problem. Would anyone have any suggestions or maybe spot
> > something I
> > > > don't? Thanks.....
> > > >
> > >
>
---------------------------------
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First we are using with P89LPC932 at that time we are using 100nF
Capacitor but after release of P89LPC932A1 we have to use 200nF .
This just for proper de-coupling between Vdd and GND.
Internal RC Oscillator is not stable so Proper de-coupling is requird for
proper communication.
Nilesh
lorcan
Hi
This may be a red herring, but we have had problems in the past with RS232 chips when the charge pump capacitors are too small. I think it was the Maxim devices that had A and B versions and one couldn't pump the out voltages high enough with the lower value caps - you can see the output voltage saw-toothing at too low a level, using a 'scope
Cheers
Lorcan
================================
SEEC Ltd
22 Newton Court
Haywards Heath
West Sussex
RH16 3BL
Tel.: 07951 467019
================================
----- Original Message -----
From: bradziegler
To: l...@yahoogroups.com
Sent: Wednesday, December 13, 2006 2:15 PM
Subject: [lpc900_users] Re: Problems communicating with 89LPC935 on my own circuit (schematic included)
In reality, I have used the same part families. My board uses a
MAX3223 instead of a MAX3221 (since the 3221 is not available as a
DIP). The only other difference is a 74HC02 instead of a 74HCT02
(which I swapped out last night and did not change anything).....
I'll probably keep playing with this some. Fustrating....
--- In l...@yahoogroups.com, "Pramod"
>
> 1. In your case you have a working circuit to compare -- then why
not
> use the same parts / families.
> You could refer to the Philips App Note -- Interfacing 3V and 5V
> applications AN240.
>
> 2. You could bypass the functionality of the 02 logic, and instead
opt
> for the 'break-detect' supported by the LPC.
>
> BR
> Pramod
>
> --- In l...@yahoogroups.com, "bradziegler"
> wrote:
> >
> > What would be the functional difference in using an LV-series
versus a
> > HC/HCT-series IC, other than low voltage in the LV case? After
> > checking this with what I have, I used a 74HC02 instead of a
74HCT02,
> > as used on the MCB900 board. Would this cause problems?
> >
> > --- In l...@yahoogroups.com, "Pramod"
> > >
> > > You have a 7402 in the schematic, if it's the same on-board
then you
> > > ought to change it to a LV family.
> > > BR
> > > Pramod
> > > --- In l...@yahoogroups.com, "bradziegler"
> > > wrote:
> > > >
> > > >
> > > > I've been working with a hardware design for my own
evaluation
> > board of
> > > > sorts that has 8 LEDs, a
> > > > couple of DIP switches, pushbuttons, etc.... The circuit is
based
> > on
> > > > the MCB900 schematic,
> > > > which I got from http://www.keil.com/mcb900/mcb900-
schematics.pdf
> > > >
> > > >
> > > > I used a simple LED flasher program to test whether or not
the
> > circuit
> > > > is working currently and on both the MCB900 and
> > > > my board, they both flash just fine. When I use FlashMagic
and my
> > > > MCB900 board, the chip
> > > > communicates just fine. However, if I use my board design
and
> > > > FlashMagic, I can't get it to communicate at all.
> > > >
> > > > The schematic to my board is below.
> > > >
> > > > I've been playing with this circuit for a couple of weeks
looking
> > at
> > > > everything and I just can't figure out what is the
> > > > problem. Would anyone have any suggestions or maybe spot
> > something I
> > > > don't? Thanks.....
> > > >
> > >
>
---------------------------------
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Re: Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - Pramod Joglekar - Dec 14 11:50:47 2006
A checklist just to make sure:
1. FlashMagic settings : Options - Advanced Options -- Hardware config - Use
RTS........
2. Jumpers inserted for 'PROG' not 'RUN'.
3. RS232 cable is straight-thru / Null Modem. All required connections --
not just Rx,Tx and Gnd.
4. 3V3 at the chip, after the transistor is selected.
On 12/13/06, bradziegler wrote:
>
> In reality, I have used the same part families. My board uses a
> MAX3223 instead of a MAX3221 (since the 3221 is not available as a
> DIP). The only other difference is a 74HC02 instead of a 74HCT02
> (which I swapped out last night and did not change anything).....
>
> I'll probably keep playing with this some. Fustrating....
> --- In l...@yahoogroups.com,
> "Pramod" wrote:
> >
> > 1. In your case you have a working circuit to compare -- then why
> not
> > use the same parts / families.
> > You could refer to the Philips App Note -- Interfacing 3V and 5V
> > applications AN240.
> >
> > 2. You could bypass the functionality of the 02 logic, and instead
> opt
> > for the 'break-detect' supported by the LPC.
> >
> > BR
> > Pramod
> >
> > --- In l...@yahoogroups.com,
> "bradziegler"
> > wrote:
> > >
> > > What would be the functional difference in using an LV-series
> versus a
> > > HC/HCT-series IC, other than low voltage in the LV case? After
> > > checking this with what I have, I used a 74HC02 instead of a
> 74HCT02,
> > > as used on the MCB900 board. Would this cause problems?
> > >
> > > --- In l...@yahoogroups.com,
> "Pramod" wrote:
> > > >
> > > > You have a 7402 in the schematic, if it's the same on-board
> then you
> > > > ought to change it to a LV family.
> > > > BR
> > > > Pramod
> > > > --- In l...@yahoogroups.com,
> "bradziegler"
>
> > > > wrote:
> > > > >
> > > > >
> > > > > I've been working with a hardware design for my own
> evaluation
> > > board of
> > > > > sorts that has 8 LEDs, a
> > > > > couple of DIP switches, pushbuttons, etc.... The circuit is
> based
> > > on
> > > > > the MCB900 schematic,
> > > > > which I got from http://www.keil.com/mcb900/mcb900-
> schematics.pdf
> > > > > .
> > > > >
> > > > > I used a simple LED flasher program to test whether or not
> the
> > > circuit
> > > > > is working currently and on both the MCB900 and
> > > > > my board, they both flash just fine. When I use FlashMagic
> and my
> > > > > MCB900 board, the chip
> > > > > communicates just fine. However, if I use my board design
> and
> > > > > FlashMagic, I can't get it to communicate at all.
> > > > >
> > > > > The schematic to my board is below.
> > > > >
> > > > > I've been playing with this circuit for a couple of weeks
> looking
> > > at
> > > > > everything and I just can't figure out what is the
> > > > > problem. Would anyone have any suggestions or maybe spot
> > > something I
> > > > > don't? Thanks.....
> > > > >
> > > >
> > >
> >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
1. FlashMagic settings : Options - Advanced Options -- Hardware config - Use
RTS........
2. Jumpers inserted for 'PROG' not 'RUN'.
3. RS232 cable is straight-thru / Null Modem. All required connections --
not just Rx,Tx and Gnd.
4. 3V3 at the chip, after the transistor is selected.
On 12/13/06, bradziegler
>
> In reality, I have used the same part families. My board uses a
> MAX3223 instead of a MAX3221 (since the 3221 is not available as a
> DIP). The only other difference is a 74HC02 instead of a 74HCT02
> (which I swapped out last night and did not change anything).....
>
> I'll probably keep playing with this some. Fustrating....
> --- In l...@yahoogroups.com
> "Pramod"
> >
> > 1. In your case you have a working circuit to compare -- then why
> not
> > use the same parts / families.
> > You could refer to the Philips App Note -- Interfacing 3V and 5V
> > applications AN240.
> >
> > 2. You could bypass the functionality of the 02 logic, and instead
> opt
> > for the 'break-detect' supported by the LPC.
> >
> > BR
> > Pramod
> >
> > --- In l...@yahoogroups.com
> "bradziegler"
> > wrote:
> > >
> > > What would be the functional difference in using an LV-series
> versus a
> > > HC/HCT-series IC, other than low voltage in the LV case? After
> > > checking this with what I have, I used a 74HC02 instead of a
> 74HCT02,
> > > as used on the MCB900 board. Would this cause problems?
> > >
> > > --- In l...@yahoogroups.com
> "Pramod"
> > > >
> > > > You have a 7402 in the schematic, if it's the same on-board
> then you
> > > > ought to change it to a LV family.
> > > > BR
> > > > Pramod
> > > > --- In l...@yahoogroups.com
> "bradziegler"
>
> > > > wrote:
> > > > >
> > > > >
> > > > > I've been working with a hardware design for my own
> evaluation
> > > board of
> > > > > sorts that has 8 LEDs, a
> > > > > couple of DIP switches, pushbuttons, etc.... The circuit is
> based
> > > on
> > > > > the MCB900 schematic,
> > > > > which I got from http://www.keil.com/mcb900/mcb900-
> schematics.pdf
> > > > >
> > > > >
> > > > > I used a simple LED flasher program to test whether or not
> the
> > > circuit
> > > > > is working currently and on both the MCB900 and
> > > > > my board, they both flash just fine. When I use FlashMagic
> and my
> > > > > MCB900 board, the chip
> > > > > communicates just fine. However, if I use my board design
> and
> > > > > FlashMagic, I can't get it to communicate at all.
> > > > >
> > > > > The schematic to my board is below.
> > > > >
> > > > > I've been playing with this circuit for a couple of weeks
> looking
> > > at
> > > > > everything and I just can't figure out what is the
> > > > > problem. Would anyone have any suggestions or maybe spot
> > > something I
> > > > > don't? Thanks.....
> > > > >
> > > >
> > >
> >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - bradziegler - Dec 16 19:50:14 2006
Everything you said is correct and setup that way. Just having a
hard time understanding #4. What do you mean by having 3v3 selected
after the transistor?
Brad Ziegler
--- In l...@yahoogroups.com, "Pramod Joglekar"
wrote:
>
> A checklist just to make sure:
> 1. FlashMagic settings : Options - Advanced Options -- Hardware
config - Use
> RTS........
> 2. Jumpers inserted for 'PROG' not 'RUN'.
> 3. RS232 cable is straight-thru / Null Modem. All required
connections --
> not just Rx,Tx and Gnd.
> 4. 3V3 at the chip, after the transistor is selected.
>
> On 12/13/06, bradziegler wrote:
> >
> > In reality, I have used the same part families. My board uses a
> > MAX3223 instead of a MAX3221 (since the 3221 is not available as
a
> > DIP). The only other difference is a 74HC02 instead of a 74HCT02
> > (which I swapped out last night and did not change anything).....
> >
> > I'll probably keep playing with this some. Fustrating....
> >
> >
> > --- In l...@yahoogroups.com
> > "Pramod" wrote:
> > >
> > > 1. In your case you have a working circuit to compare -- then
why
> > not
> > > use the same parts / families.
> > > You could refer to the Philips App Note -- Interfacing 3V and
5V
> > > applications AN240.
> > >
> > > 2. You could bypass the functionality of the 02 logic, and
instead
> > opt
> > > for the 'break-detect' supported by the LPC.
> > >
> > > BR
> > > Pramod
> > >
> > > --- In l...@yahoogroups.com
> > "bradziegler"
> > > wrote:
> > > >
> > > > What would be the functional difference in using an LV-series
> > versus a
> > > > HC/HCT-series IC, other than low voltage in the LV case?
After
> > > > checking this with what I have, I used a 74HC02 instead of a
> > 74HCT02,
> > > > as used on the MCB900 board. Would this cause problems?
> > > >
> > > > --- In l...@yahoogroups.com
> > "Pramod" wrote:
> > > > >
> > > > > You have a 7402 in the schematic, if it's the same on-board
> > then you
> > > > > ought to change it to a LV family.
> > > > > BR
> > > > > Pramod
> > > > > --- In l...@yahoogroups.com
> > "bradziegler"
> >
> > > > > wrote:
> > > > > >
> > > > > >
> > > > > > I've been working with a hardware design for my own
> > evaluation
> > > > board of
> > > > > > sorts that has 8 LEDs, a
> > > > > > couple of DIP switches, pushbuttons, etc.... The circuit
is
> > based
> > > > on
> > > > > > the MCB900 schematic,
> > > > > > which I got from http://www.keil.com/mcb900/mcb900-
> > schematics.pdf
> > > > > > .
> > > > > >
> > > > > > I used a simple LED flasher program to test whether or
not
> > the
> > > > circuit
> > > > > > is working currently and on both the MCB900 and
> > > > > > my board, they both flash just fine. When I use
FlashMagic
> > and my
> > > > > > MCB900 board, the chip
> > > > > > communicates just fine. However, if I use my board design
> > and
> > > > > > FlashMagic, I can't get it to communicate at all.
> > > > > >
> > > > > > The schematic to my board is below.
> > > > > >
> > > > > > I've been playing with this circuit for a couple of weeks
> > looking
> > > > at
> > > > > > everything and I just can't figure out what is the
> > > > > > problem. Would anyone have any suggestions or maybe spot
> > > > something I
> > > > > > don't? Thanks.....
> > > > > >
> > > > >
> > > >
> > >
> >
> >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
hard time understanding #4. What do you mean by having 3v3 selected
after the transistor?
Brad Ziegler
--- In l...@yahoogroups.com, "Pramod Joglekar"
>
> A checklist just to make sure:
> 1. FlashMagic settings : Options - Advanced Options -- Hardware
config - Use
> RTS........
> 2. Jumpers inserted for 'PROG' not 'RUN'.
> 3. RS232 cable is straight-thru / Null Modem. All required
connections --
> not just Rx,Tx and Gnd.
> 4. 3V3 at the chip, after the transistor is selected.
>
> On 12/13/06, bradziegler
> >
> > In reality, I have used the same part families. My board uses a
> > MAX3223 instead of a MAX3221 (since the 3221 is not available as
a
> > DIP). The only other difference is a 74HC02 instead of a 74HCT02
> > (which I swapped out last night and did not change anything).....
> >
> > I'll probably keep playing with this some. Fustrating....
> >
> >
> > --- In l...@yahoogroups.com
> > "Pramod"
> > >
> > > 1. In your case you have a working circuit to compare -- then
why
> > not
> > > use the same parts / families.
> > > You could refer to the Philips App Note -- Interfacing 3V and
5V
> > > applications AN240.
> > >
> > > 2. You could bypass the functionality of the 02 logic, and
instead
> > opt
> > > for the 'break-detect' supported by the LPC.
> > >
> > > BR
> > > Pramod
> > >
> > > --- In l...@yahoogroups.com
> > "bradziegler"
> > > wrote:
> > > >
> > > > What would be the functional difference in using an LV-series
> > versus a
> > > > HC/HCT-series IC, other than low voltage in the LV case?
After
> > > > checking this with what I have, I used a 74HC02 instead of a
> > 74HCT02,
> > > > as used on the MCB900 board. Would this cause problems?
> > > >
> > > > --- In l...@yahoogroups.com
> > "Pramod"
> > > > >
> > > > > You have a 7402 in the schematic, if it's the same on-board
> > then you
> > > > > ought to change it to a LV family.
> > > > > BR
> > > > > Pramod
> > > > > --- In l...@yahoogroups.com
> > "bradziegler"
> >
> > > > > wrote:
> > > > > >
> > > > > >
> > > > > > I've been working with a hardware design for my own
> > evaluation
> > > > board of
> > > > > > sorts that has 8 LEDs, a
> > > > > > couple of DIP switches, pushbuttons, etc.... The circuit
is
> > based
> > > > on
> > > > > > the MCB900 schematic,
> > > > > > which I got from http://www.keil.com/mcb900/mcb900-
> > schematics.pdf
> > > > > >
> > > > > >
> > > > > > I used a simple LED flasher program to test whether or
not
> > the
> > > > circuit
> > > > > > is working currently and on both the MCB900 and
> > > > > > my board, they both flash just fine. When I use
FlashMagic
> > and my
> > > > > > MCB900 board, the chip
> > > > > > communicates just fine. However, if I use my board design
> > and
> > > > > > FlashMagic, I can't get it to communicate at all.
> > > > > >
> > > > > > The schematic to my board is below.
> > > > > >
> > > > > > I've been playing with this circuit for a couple of weeks
> > looking
> > > > at
> > > > > > everything and I just can't figure out what is the
> > > > > > problem. Would anyone have any suggestions or maybe spot
> > > > something I
> > > > > > don't? Thanks.....
> > > > > >
> > > > >
> > > >
> > >
> >
> >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - john - Dec 16 22:12:58 2006
I think he's asking if the transistor is working (turning Off and On
for the required pwr sequence) and if 3.3V is being supplied via the
transistor to the uC.
--- In l...@yahoogroups.com, "bradziegler"
wrote:
>
> Everything you said is correct and setup that way. Just having a
> hard time understanding #4. What do you mean by having 3v3 selected
> after the transistor?
>
> Brad Ziegler
>
> --- In l...@yahoogroups.com, "Pramod Joglekar"
> wrote:
> >
> > A checklist just to make sure:
> > 1. FlashMagic settings : Options - Advanced Options -- Hardware
> config - Use
> > RTS........
> > 2. Jumpers inserted for 'PROG' not 'RUN'.
> > 3. RS232 cable is straight-thru / Null Modem. All required
> connections --
> > not just Rx,Tx and Gnd.
> > 4. 3V3 at the chip, after the transistor is selected.
> >
> >
> >
> > On 12/13/06, bradziegler wrote:
> > >
> > > In reality, I have used the same part families. My board uses a
> > > MAX3223 instead of a MAX3221 (since the 3221 is not available as
> a
> > > DIP). The only other difference is a 74HC02 instead of a 74HCT02
> > > (which I swapped out last night and did not change anything).....
> > >
> > > I'll probably keep playing with this some. Fustrating....
> > >
> > >
> > > --- In l...@yahoogroups.com
> > > "Pramod" wrote:
> > > >
> > > > 1. In your case you have a working circuit to compare -- then
> why
> > > not
> > > > use the same parts / families.
> > > > You could refer to the Philips App Note -- Interfacing 3V and
> 5V
> > > > applications AN240.
> > > >
> > > > 2. You could bypass the functionality of the 02 logic, and
> instead
> > > opt
> > > > for the 'break-detect' supported by the LPC.
> > > >
> > > > BR
> > > > Pramod
> > > >
> > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > > > wrote:
> > > > >
> > > > > What would be the functional difference in using an LV-series
> > > versus a
> > > > > HC/HCT-series IC, other than low voltage in the LV case?
> After
> > > > > checking this with what I have, I used a 74HC02 instead of a
> > > 74HCT02,
> > > > > as used on the MCB900 board. Would this cause problems?
> > > > >
> > > > > --- In l...@yahoogroups.com
> > > "Pramod" wrote:
> > > > > >
> > > > > > You have a 7402 in the schematic, if it's the same on-board
> > > then you
> > > > > > ought to change it to a LV family.
> > > > > > BR
> > > > > > Pramod
> > > > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > >
> > > > > > wrote:
> > > > > > >
> > > > > > >
> > > > > > > I've been working with a hardware design for my own
> > > evaluation
> > > > > board of
> > > > > > > sorts that has 8 LEDs, a
> > > > > > > couple of DIP switches, pushbuttons, etc.... The circuit
> is
> > > based
> > > > > on
> > > > > > > the MCB900 schematic,
> > > > > > > which I got from http://www.keil.com/mcb900/mcb900-
> > > schematics.pdf
> > > > > > > .
> > > > > > >
> > > > > > > I used a simple LED flasher program to test whether or
> not
> > > the
> > > > > circuit
> > > > > > > is working currently and on both the MCB900 and
> > > > > > > my board, they both flash just fine. When I use
> FlashMagic
> > > and my
> > > > > > > MCB900 board, the chip
> > > > > > > communicates just fine. However, if I use my board design
> > > and
> > > > > > > FlashMagic, I can't get it to communicate at all.
> > > > > > >
> > > > > > > The schematic to my board is below.
> > > > > > >
> > > > > > > I've been playing with this circuit for a couple of weeks
> > > looking
> > > > > at
> > > > > > > everything and I just can't figure out what is the
> > > > > > > problem. Would anyone have any suggestions or maybe spot
> > > > > something I
> > > > > > > don't? Thanks.....
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> > >
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
for the required pwr sequence) and if 3.3V is being supplied via the
transistor to the uC.
--- In l...@yahoogroups.com, "bradziegler"
wrote:
>
> Everything you said is correct and setup that way. Just having a
> hard time understanding #4. What do you mean by having 3v3 selected
> after the transistor?
>
> Brad Ziegler
>
> --- In l...@yahoogroups.com, "Pramod Joglekar"
>
> >
> > A checklist just to make sure:
> > 1. FlashMagic settings : Options - Advanced Options -- Hardware
> config - Use
> > RTS........
> > 2. Jumpers inserted for 'PROG' not 'RUN'.
> > 3. RS232 cable is straight-thru / Null Modem. All required
> connections --
> > not just Rx,Tx and Gnd.
> > 4. 3V3 at the chip, after the transistor is selected.
> >
> >
> >
> > On 12/13/06, bradziegler
> > >
> > > In reality, I have used the same part families. My board uses a
> > > MAX3223 instead of a MAX3221 (since the 3221 is not available as
> a
> > > DIP). The only other difference is a 74HC02 instead of a 74HCT02
> > > (which I swapped out last night and did not change anything).....
> > >
> > > I'll probably keep playing with this some. Fustrating....
> > >
> > >
> > > --- In l...@yahoogroups.com
> > > "Pramod"
> > > >
> > > > 1. In your case you have a working circuit to compare -- then
> why
> > > not
> > > > use the same parts / families.
> > > > You could refer to the Philips App Note -- Interfacing 3V and
> 5V
> > > > applications AN240.
> > > >
> > > > 2. You could bypass the functionality of the 02 logic, and
> instead
> > > opt
> > > > for the 'break-detect' supported by the LPC.
> > > >
> > > > BR
> > > > Pramod
> > > >
> > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > > > wrote:
> > > > >
> > > > > What would be the functional difference in using an LV-series
> > > versus a
> > > > > HC/HCT-series IC, other than low voltage in the LV case?
> After
> > > > > checking this with what I have, I used a 74HC02 instead of a
> > > 74HCT02,
> > > > > as used on the MCB900 board. Would this cause problems?
> > > > >
> > > > > --- In l...@yahoogroups.com
> > > "Pramod"
> > > > > >
> > > > > > You have a 7402 in the schematic, if it's the same on-board
> > > then you
> > > > > > ought to change it to a LV family.
> > > > > > BR
> > > > > > Pramod
> > > > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > >
> > > > > > wrote:
> > > > > > >
> > > > > > >
> > > > > > > I've been working with a hardware design for my own
> > > evaluation
> > > > > board of
> > > > > > > sorts that has 8 LEDs, a
> > > > > > > couple of DIP switches, pushbuttons, etc.... The circuit
> is
> > > based
> > > > > on
> > > > > > > the MCB900 schematic,
> > > > > > > which I got from http://www.keil.com/mcb900/mcb900-
> > > schematics.pdf
> > > > > > >
> > > > > > >
> > > > > > > I used a simple LED flasher program to test whether or
> not
> > > the
> > > > > circuit
> > > > > > > is working currently and on both the MCB900 and
> > > > > > > my board, they both flash just fine. When I use
> FlashMagic
> > > and my
> > > > > > > MCB900 board, the chip
> > > > > > > communicates just fine. However, if I use my board design
> > > and
> > > > > > > FlashMagic, I can't get it to communicate at all.
> > > > > > >
> > > > > > > The schematic to my board is below.
> > > > > > >
> > > > > > > I've been playing with this circuit for a couple of weeks
> > > looking
> > > > > at
> > > > > > > everything and I just can't figure out what is the
> > > > > > > problem. Would anyone have any suggestions or maybe spot
> > > > > something I
> > > > > > > don't? Thanks.....
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> > >
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
Re: Problems communicating with 89LPC935 on my own circuit (schematic included) - Pramod - Dec 18 9:02:53 2006
Check voltage at LPC, after the transistor has been driven ON by the
'02. You could have the transistor dropping more than 0.2V(Vce),
preventing proper operation of the LPC.
--- In l...@yahoogroups.com, "bradziegler"
wrote:
>
> Everything you said is correct and setup that way. Just having a
> hard time understanding #4. What do you mean by having 3v3 selected
> after the transistor?
>
> Brad Ziegler
>
> --- In l...@yahoogroups.com, "Pramod Joglekar"
> wrote:
> >
> > A checklist just to make sure:
> > 1. FlashMagic settings : Options - Advanced Options -- Hardware
> config - Use
> > RTS........
> > 2. Jumpers inserted for 'PROG' not 'RUN'.
> > 3. RS232 cable is straight-thru / Null Modem. All required
> connections --
> > not just Rx,Tx and Gnd.
> > 4. 3V3 at the chip, after the transistor is selected.
> >
> >
> >
> > On 12/13/06, bradziegler wrote:
> > >
> > > In reality, I have used the same part families. My board uses a
> > > MAX3223 instead of a MAX3221 (since the 3221 is not available as
> a
> > > DIP). The only other difference is a 74HC02 instead of a 74HCT02
> > > (which I swapped out last night and did not change anything).....
> > >
> > > I'll probably keep playing with this some. Fustrating....
> > >
> > >
> > > --- In l...@yahoogroups.com
> > > "Pramod" wrote:
> > > >
> > > > 1. In your case you have a working circuit to compare -- then
> why
> > > not
> > > > use the same parts / families.
> > > > You could refer to the Philips App Note -- Interfacing 3V and
> 5V
> > > > applications AN240.
> > > >
> > > > 2. You could bypass the functionality of the 02 logic, and
> instead
> > > opt
> > > > for the 'break-detect' supported by the LPC.
> > > >
> > > > BR
> > > > Pramod
> > > >
> > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > > > wrote:
> > > > >
> > > > > What would be the functional difference in using an LV-series
> > > versus a
> > > > > HC/HCT-series IC, other than low voltage in the LV case?
> After
> > > > > checking this with what I have, I used a 74HC02 instead of a
> > > 74HCT02,
> > > > > as used on the MCB900 board. Would this cause problems?
> > > > >
> > > > > --- In l...@yahoogroups.com
> > > "Pramod" wrote:
> > > > > >
> > > > > > You have a 7402 in the schematic, if it's the same on-board
> > > then you
> > > > > > ought to change it to a LV family.
> > > > > > BR
> > > > > > Pramod
> > > > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > >
> > > > > > wrote:
> > > > > > >
> > > > > > >
> > > > > > > I've been working with a hardware design for my own
> > > evaluation
> > > > > board of
> > > > > > > sorts that has 8 LEDs, a
> > > > > > > couple of DIP switches, pushbuttons, etc.... The circuit
> is
> > > based
> > > > > on
> > > > > > > the MCB900 schematic,
> > > > > > > which I got from http://www.keil.com/mcb900/mcb900-
> > > schematics.pdf
> > > > > > > .
> > > > > > >
> > > > > > > I used a simple LED flasher program to test whether or
> not
> > > the
> > > > > circuit
> > > > > > > is working currently and on both the MCB900 and
> > > > > > > my board, they both flash just fine. When I use
> FlashMagic
> > > and my
> > > > > > > MCB900 board, the chip
> > > > > > > communicates just fine. However, if I use my board design
> > > and
> > > > > > > FlashMagic, I can't get it to communicate at all.
> > > > > > >
> > > > > > > The schematic to my board is below.
> > > > > > >
> > > > > > > I've been playing with this circuit for a couple of weeks
> > > looking
> > > > > at
> > > > > > > everything and I just can't figure out what is the
> > > > > > > problem. Would anyone have any suggestions or maybe spot
> > > > > something I
> > > > > > > don't? Thanks.....
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> > >
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
'02. You could have the transistor dropping more than 0.2V(Vce),
preventing proper operation of the LPC.
--- In l...@yahoogroups.com, "bradziegler"
wrote:
>
> Everything you said is correct and setup that way. Just having a
> hard time understanding #4. What do you mean by having 3v3 selected
> after the transistor?
>
> Brad Ziegler
>
> --- In l...@yahoogroups.com, "Pramod Joglekar"
>
> >
> > A checklist just to make sure:
> > 1. FlashMagic settings : Options - Advanced Options -- Hardware
> config - Use
> > RTS........
> > 2. Jumpers inserted for 'PROG' not 'RUN'.
> > 3. RS232 cable is straight-thru / Null Modem. All required
> connections --
> > not just Rx,Tx and Gnd.
> > 4. 3V3 at the chip, after the transistor is selected.
> >
> >
> >
> > On 12/13/06, bradziegler
> > >
> > > In reality, I have used the same part families. My board uses a
> > > MAX3223 instead of a MAX3221 (since the 3221 is not available as
> a
> > > DIP). The only other difference is a 74HC02 instead of a 74HCT02
> > > (which I swapped out last night and did not change anything).....
> > >
> > > I'll probably keep playing with this some. Fustrating....
> > >
> > >
> > > --- In l...@yahoogroups.com
> > > "Pramod"
> > > >
> > > > 1. In your case you have a working circuit to compare -- then
> why
> > > not
> > > > use the same parts / families.
> > > > You could refer to the Philips App Note -- Interfacing 3V and
> 5V
> > > > applications AN240.
> > > >
> > > > 2. You could bypass the functionality of the 02 logic, and
> instead
> > > opt
> > > > for the 'break-detect' supported by the LPC.
> > > >
> > > > BR
> > > > Pramod
> > > >
> > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > > > wrote:
> > > > >
> > > > > What would be the functional difference in using an LV-series
> > > versus a
> > > > > HC/HCT-series IC, other than low voltage in the LV case?
> After
> > > > > checking this with what I have, I used a 74HC02 instead of a
> > > 74HCT02,
> > > > > as used on the MCB900 board. Would this cause problems?
> > > > >
> > > > > --- In l...@yahoogroups.com
> > > "Pramod"
> > > > > >
> > > > > > You have a 7402 in the schematic, if it's the same on-board
> > > then you
> > > > > > ought to change it to a LV family.
> > > > > > BR
> > > > > > Pramod
> > > > > > --- In l...@yahoogroups.com
> > > "bradziegler"
> > >
> > > > > > wrote:
> > > > > > >
> > > > > > >
> > > > > > > I've been working with a hardware design for my own
> > > evaluation
> > > > > board of
> > > > > > > sorts that has 8 LEDs, a
> > > > > > > couple of DIP switches, pushbuttons, etc.... The circuit
> is
> > > based
> > > > > on
> > > > > > > the MCB900 schematic,
> > > > > > > which I got from http://www.keil.com/mcb900/mcb900-
> > > schematics.pdf
> > > > > > >
> > > > > > >
> > > > > > > I used a simple LED flasher program to test whether or
> not
> > > the
> > > > > circuit
> > > > > > > is working currently and on both the MCB900 and
> > > > > > > my board, they both flash just fine. When I use
> FlashMagic
> > > and my
> > > > > > > MCB900 board, the chip
> > > > > > > communicates just fine. However, if I use my board design
> > > and
> > > > > > > FlashMagic, I can't get it to communicate at all.
> > > > > > >
> > > > > > > The schematic to my board is below.
> > > > > > >
> > > > > > > I've been playing with this circuit for a couple of weeks
> > > looking
> > > > > at
> > > > > > > everything and I just can't figure out what is the
> > > > > > > problem. Would anyone have any suggestions or maybe spot
> > > > > something I
> > > > > > > don't? Thanks.....
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> > >
> > >
>
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )