LPC2300 sometimes not starting

[lpcware]

Content originally posted in LPCWare by m2babaey on Tue Jun 18 22:04:40 MST 2013
Hi
I am testing an LED blink program on LPC2388
The problem is that sometimes that I connect the power it works, and sometimes it doesn't work, why?

I have a pull up resistor on P2.10
I also searched the net and found a similar problem here but I am using Keil and I don't know how to define startup_from _reset in keil

Any help would be extremely appreciated

[lpcware]

Content originally posted in LPCWare by R2D2 on Wed Jun 19 00:11:51 MST 2013

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Quote: m2babaey
I had a very big pull up resistor on reset pin (33k) I tried 220ohm first (it worked) and 1k now witch almost works

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That's showing that your hardware is faulty. 22k/100nF is a good choice.
Of course that's not working if your reseet circuit is not working. There you should, as mentioned already, follow good old Keil schematic and use 47k/100nF.

[lpcware]

Content originally posted in LPCWare by m2babaey on Tue Jun 18 23:43:35 MST 2013
Thanks for your hints
I have lpc2388 on a board designed by myself
The main problem was fixed. now each time I connect the power, it starts working
I had a very big pull up resistor on reset pin (33k) I tried 220ohm first (it worked) and 1k now witch almost works

But there is still one problem. When I reset the core by reset pin, it doesn't restart and I have to disconnect power to reset the core

How can I make it start up after reset?
Thanks

[lpcware]

Content originally posted in LPCWare by R2D2 on Tue Jun 18 23:03:03 MST 2013

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Quote: m2babaey
I am testing an LED blink program on LPC2388
The problem is that sometimes that I connect the power it works, and sometimes it doesn't work, why?

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Is it a naked 2388 or has is something like a board around?

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Quote: m2babaey

I have a pull up resistor on P2.10
I also searched the net and found a similar problem here but I am using Keil and I don't know how to define startup_from _reset in keil

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There is a [COLOR=Red]Keil forum [/COLOR]which is probably answering Keil questions:

http://www.keil.com/forum/threads.asp

Is it a cheap pullup or has it also a value?

Keil samples are usually running with Keil hardware like Keil MCB2388 Board. Its schematic shows correct pullups.

http://www.keil.com/mcb2300/mcb2300-schematics.pdf