Zeroplus Arduino starter kit with Logic Analyzer Manual page 79

REAL LIFE APPLICATIONS
• Most smartphones embed a proximity sensor that turns off the screen
during a call when it approaches your ear. It avoids accidental
touches. A light sensor is preferred over a capacitive sensing based
solution in cost-effective projects.
REMARKS
• We could do without the photoresistor. For example you can try to
write a piece of code that tests all possible values.
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