Embedded Planet, Inc.
epConnected Asset | Product User Manual
Document Version: 1.0.0 | 26 Jan 22
Embedded Planet, Inc. | 31225 Bainbridge Rd Suite N, Solon, OH 44139 | 216-245-4180 | www.embeddedplanet.com |
Page 16 of 37
9.5.
Sensors | Temperature & Humidity (U14)
The onboard temperature & humidity option is provided by the Silicon Labs Si7021-A20. This device
accommodates an I
2
C operating frequency of up to 400kHz in fast mode. The I
2
C address is 1000000b (0x40).
More on this device can be found at:
https://www.silabs.com/sensors/humidity/si7006-13-20-21-34/device.si7021-a20-gm
*Shown without U.FL cables connected for visual reference only. The device must have its U.FL cables connected.
9.5.1.
U14 | Temperature
The operating range of the temperature sensor is -40°C to +85°C. The typical accuracy is 0.3°C in
the -10°C to +85°C range, and up to 0.9°C outside that range. Once a temperature measurement has
been made the results may be converted to [°C] by using the following expression:
Where the variable
Temp_Code
is the 16-bit word returned by the Si7021.
9.5.2.
U14 | Humidity
The operating range of the humidity sensor is 0-100% relative humidity, non-condensing. The
typical accuracy is 2% in the 0-80% RH range, and 3% in the 80-100%RH range. Once a relative humidity
measurement has been made, the results may be converted to percent relative humidity (%RH) by using
the following expression:
where the variable
RH_Code
is the 16-bit word returned by the Si7021.
Due to normal variations in RH accuracy of the device, it is possible for the measured value of
%RH to be slightly less than 0 when the actual RH level is close to or equal to 0. Similarly, the measured
value of %RH may be slightly greater than 100 when the actual RH level is close to or equal to 100. This
is expected behavior, and it is acceptable to limit the range of RH results to 0 to 100%RH in the host
software by truncating values that are slightly outside of this range.
U14: Temperature &
Humidity
Summary of Contents for epConnected Asset
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