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• Make sure all three jumpers are set to "RUN" (left position)
• Attach the provided battery pack to J6 (red cable = "+") an turn it ON
• The LPC90x demo runs.
o The LED will blink according to analog voltage selected with
potentiometer (turn potentiometer to adjust frequency)
o Push Button will reset the application
The Demo code makes use of the on-chip analog comparator on the LPC90x.
Together with resistor R2 and capacitor C4, the software uses the on-chip analog
comparator as a Sigma-Delta Analog to Digital Converter. This method is
described in detail in AN10187, "Low-cost A/D-Conversion with Philips LPC
Microcontrollers". This Application Note (among others) is included on the CD.
The digital representation of the analog voltage provided by the potentiometer
controls the frequency with which the LED is turned on and off.
While the push button is pressed, it holds the application in Reset via a LOW signal
on the Reset pin. Please note that the LPC90x is equipped with an on-chip
Power-On Reset (POR) circuit that automatically provides a clean reset signal to
the device on power-up. The external Reset pin is ONLY needed if the chip needs
to be reset manually or by another device in the application. Most of the time, the
internal power-on reset is sufficient and this pin (P1.5) becomes a valuable
general-purpose input pin.
PAB90x-1 Getting Started V1.0
Page 20
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