Component questions - LPC1343

[Andersonf]

Hello, how are you?

I'm buying the components to build the LPC1343.
I'm having some issues. For example: can not find the MOSFET BSS84P
L6327, can I substitute some other, if so, I have to replace the
resistors?
Capacitors C1 and C2 crystal scheme is the 18PF, but the list asks
22pF ... which one to buy?
Resistors R4 and R5 of the buttons in the scheme is 12KOhm, but the
list asks 15KOhm ... (only need a single resistor for the button?)
what to buy?
Capacitor C7 VDD to GND in the scheme is 10nF, longer on the list
asks 0.1uF ... what for?
Capacitor C9 VDD to GND in the scheme is 10uF, but the list does not
have it ... get it?

With this card can record the program in the microcontroller can also
exchange information / communication PC -> MCU and MCU -> PC?


I'm putting together this project to connect to the biosensor by SPi,
also plan to build the insulating board of two layers.

Thanks,

[Opendous Inc.]

If you search DigiKey or other suppliers for just BSS84 there are a
lot of compatible "Logic Level Gate" P-CH MOSFETs. In fact, just
about any "Logic Level Gate" SOT-23-3 P-CH MOSFET should work.

For testing, you could also just short the drain and source pins and
not install the FET. However, this would cause the USB D+ line to be
always pulled up to 3.3V through the 1.5k resistor which tells the USB
bus that it is dealing with a Full-Speed Device. This could cause
problems if your firmware does not properly function.

>Capacitors C1 and C2 crystal scheme is the
>18PF, but the list asks 22pF ... which one to buy?

This depends on the exact crystal you use but any value between 16pF
and 24pF will work.

>Resistors R4 and R5 of the buttons in the
>scheme is 12KOhm, but the list asks 15KOhm

These are just pull-up resistors so use any value between 10k and
30k that you have.

>Capacitor C7 VDD to GND in the scheme is
>10nF, longer on the list asks 0.1uF ... what for?
>Capacitor C9 VDD to GND in the scheme is
>10uF, but the list does not have it ... get it?

10nF = 0.01uF = 10000pF. Yes, the 10uF is important. I seem to
have overlooked these.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=478-1383-1-ND
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=445-1363-1-ND

You can use any 0805 size, 6V+, X?R ceramic (or better) capacitors.

>With this card can record the program in the
>microcontroller can also exchange information
>/ communication PC -> MCU and MCU -> PC?

Yes, you will be able to do so. However, I am not aware of any Open
Source demos of such.

[Casainho]

On Sun, Mar 13, 2011 at 4:21 PM, Andersonf <ande...@gmail.com> wrote:
> Hello, how are you?

Hello :-)

For what I know of my experiences with LPC and that same board from Opendous,

>  I'm buying the components to build the LPC1343.
>  I'm having some issues. For example: can not find the MOSFET BSS84P

That mosfet acts just as a switch, I believe any other P mosfet will
work. That one may be the cheaper on Farnell/Mouser, etc. I am sure an
expensive one will work also.

> L6327, can I substitute some other, if so, I have to replace the
> resistors?

>  Capacitors C1 and C2 crystal scheme is the 18PF, but the list asks
> 22pF ... which one to buy?

I think both values should work.

>  Resistors R4 and R5 of the buttons in the scheme is 12KOhm, but the
> list asks 15KOhm ... (only need a single resistor for the button?)
> what to buy?

If that ones are just pull ups/down, so both of that values should work.

>  Capacitor C7 VDD to GND in the scheme is 10nF, longer on the list
> asks 0.1uF ... what for?
>  Capacitor C9 VDD to GND in the scheme is 10uF, but the list does not
> have it ... get it?

Just buy that capacitors anyway, later you can assembly them or not,
if you need.

Please wait for Matt answers. I did build this board but it never
worked, however it were an old version. Actual version should work
well. I like a lot this board nad LPC13xx :-)

[Andersonf]

OK, thank you for answers.
Once you finish the board, post the results ... =]