LPC1769 supply

[lpcware]

Content originally posted in LPCWare by timer on Sun Jun 17 06:59:54 MST 2012
Hi,

I have nen LPCXpresso LPC1769 Board.
My programm with at the moment only a PWM-Function works quite well when it is connectet with usb by the LPC-Link.
But when it is externaly powered by the 3V3 pin the LED2 is glowing a little bit, but I doesn't measure the PWM-Signal. But when I connect additionally an extarnal 5V source to the VIN then everything works well again.

Due to the schematics the target board doesn't need the 5V but why it looks like my programm doesn't start.

Thanks for help.
Tim

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Sun Jun 17 13:41:03 MST 2012

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Quote: timer
I separate only the 11/12 line and now it works fine.

I think this should be written somewhere ;)

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It's written here now :), which is the purpose of this Crowdsourcing Forum (or in this case: Krautsourcing  ;))

[lpcware]

Content originally posted in LPCWare by timer on Sun Jun 17 12:39:46 MST 2012
Yes, it's original.
I separate only the 11/12 line and now it works fine.


I thin this should be written somewhere ;)


Thank you both very much.

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Sun Jun 17 09:08:35 MST 2012
So we are talking about an original LPCXpresso1769?

Did you measure your (3.3V) supply current?

Did you check GND connection?

I would strongly recommend to separate your target board from LPC-link :)

JTAG_RESETX J4-11/12 can hold your Reset down :mad:

[lpcware]

Content originally posted in LPCWare by timer on Sun Jun 17 08:55:29 MST 2012
The boards are still together and I use the Redlib (nohost).

I tryed the LED flashing SysTick application example and it's the same behavior. Even without my Prototypeboard, only 3.3V from my power supply unit to the J6-28.

The result is, the led2 doesn't flash, it glows low.

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Sun Jun 17 07:43:52 MST 2012

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Quote: timer
So for me it's like the programm stick.

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If you are not sure if your code is faulty, just post your axf file and describe which PWMOUT you've used :)

[lpcware]

Content originally posted in LPCWare by Rob65 on Sun Jun 17 07:28:50 MST 2012
Separating the board is not really needed - I've used LPCXpresso boards powered through the 3V3 pin without separating. But if you want to be sure, you could just cut the traces and place jumpers like Embedded Artists does on their LPC1227 LPC-link board.

Rob

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Sun Jun 17 07:23:09 MST 2012

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Quote: timer
The J6-28 and the Ozsi shows me a perfect 3.3 without noise.
On the pin where the PWM-Signal should be is only a 3.3 and the led2 is glowing. So for me it's like the programm stick.

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Did you separate your target board?

Is your project a semihosting project?

[lpcware]

Content originally posted in LPCWare by Rob65 on Sun Jun 17 07:22:22 MST 2012

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Quote: Zero
Which pins did you use to connect 3.3V?

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On my board there is only one 3V3 pin :p Applying a 3V3 source that can deliver 250 mA works OK for me.

Except of course when I have the wrong libraries linked (semihosting) where my program is trying to communicate with the debugger.

Try to use the libraries without semihosting - maybe it's just a software issue.
You can select which libraries to use from the project properties: C/C++ Build - Settings, then select the MCU Linked - Target section and on "Use C library"  select "Redlib (nohost)" or "Newlib (nohost)" depending of what you use.

You could also initialize P0.22 as output and switch the LED on as first statement in main() so you know that your program is at least starting.
[INDENT]Rob
[/INDENT]

[lpcware]

Content originally posted in LPCWare by timer on Sun Jun 17 07:21:54 MST 2012
The J6-28 and the Ozsi shows me a perfect 3.3 without noise.
On the pin where the PWM-Signal should be is only a 3.3 and the led2 is glowing. So for me it's like the programm stick.

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Sun Jun 17 07:12:27 MST 2012

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Quote: timer
Thanks for this fast reaction.

The 3.3V supply have a max Power of over 7W.

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So 2A should be enough :rolleyes:

Which pins did you use to connect 3.3V?

[lpcware]

Content originally posted in LPCWare by timer on Sun Jun 17 07:10:13 MST 2012
Thanks for this fast reaction.

The 3.3V supply have a max Power of over 7W.

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Sun Jun 17 07:07:29 MST 2012
How much power is your 3.3V source supplying?