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To actually get any usable humidity values, a relatively accurate temperature measurement is also needed, as relative humidity is very dependant on temperature.
Figure 5. Capacitive Humudity Sensor Schematic.
http://www.arduino.cc/en/Tutorial/CapacitanceMeter
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Sensor proceeds to send the data, each bit starts with 50µs low, then the bit data itself; 26 to 28µs for ‘0’, 70µs for ‘1’
Figure 56. Timing Diagram. [5]
Applications: Arduino + Humidity Sensor + Temperature Sensor
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