User's Guide

Smart Room Sensor (Gen4) User Guide T0007525_UG Version 1.0
TEKTELIC Communications Inc. Page 10 of 18
corresponding to the light levels to be detected. The output of the light transducer is an analog
voltage that is read by the MCU ADC.
Vishay’s TEMT6200FX1 is a phototransistor specifically designed for ambient light sensing as it
includes a filter to give a response similar to the human eye, thus being capable of detecting
weak light to typical work light conditions.
1.2.4 Barometer
A barometer is included in the Room Sensor in order to measure the barometric air pressure.
Infineon’s DPS310 is designed for low power applications while provided highly accurate
measurements. The sensor can operate over a range of 300 hPa to 1200 hPa, and can
communicate over I
2
C or SPI protocols. The pressure accuracy of the sensor is ±1 hPa between
300 hPa and 1200 hPa while operating between 0°C and 65°C.
1.2.5 CO
2
Concentration Sensor
The Room Sensor includes the Senseair Sunrise to measure the CO
2
concentration using non-
dispersive infrared (NDIR). It operates over an I
2
C interface and can measure in the range of 400
ppm to 5000 ppm with an accuracy of up to ±30 ppm +3% of the reading. This sensor also
features an extended range of up to 10000 ppm with a projected accuracy of extended range
±10% of the reading.
1.2.6 PIR Sensor
A motion detection feature on the Room Sensor is implemented with a PIR sensor. Panasonic’s
EKM1291111 is specifically designed to be sensitive enough to detect small movements with a
wide field of view of 104° x 104°.
The motion detection system uses a ceiling mount type lens that has an expected coverage area
of 7.7 m x 7.7 m when ceiling mounted at a height of 3 m. Note that this is the theoretical
maximum sense range claimed by the transducer manufacturer. The sense range is determined
as the projection of the transducer FoV on the ground, and therefore, should not be interpreted
as the coverage area where the sensor can detect moving people. In general, due to the conical
nature of the transducer FoV, people need to be closer to the sensor to be detected. The
amount of IR radiation from a moving person, which is also impacted by the person’s clothing
or type of skin cover, also plays an important role at determining the detection range.