Lpc2000

Hi Varuzhan,

> There are several examples of the LPC2148 USB port
> usage, though there are very difficult to adapt for
> user's need.  But, besides, some have very strange
> behaviour.  For example the USBHID from Keil, running
> on the MCB2148 evaluaton board.
> To be recogized by PC, the USB cable should be disconnected
> from the board and then connected again.  After it
> the example starts to work..., but until the microcontroller
> was reseted.  Then one again needs to repeat the
> disconnect/connect procedure to make the board work.
> Sure, such software is useless for more or less real usage.
> For example, the microcontroller can be resetted by the
> watchdog and the USB connection will be lost.
> So my questions:
> 

When working with the USB examples be sure to start with the USB audio
example.  It appears to be the most recent.

> 1. Is such behaviour property of LPC2148 or just the
> Keil example?

I've ported two of the Keil USB based examples to IAR without the problem
you mention.  The Keil board does not implement the "Connect" feature,
perhaps this is the difference.

> 2. Are there available examples of the LPC2148 USB usage
> without such problems?

The IAR LPC2148 KS board implements the "Connect" feature.

The Keil examples are a reasonable starting point, but still require some
work.  When using these examples I would advise an Ellisys USB analyzer to
confirm your work.


Joel