
Kona Home Sensor TRM
T0005370_TRM
Version Rev-C 1.0
TEKTELIC Communications Inc.
Confidential
Page 28 of 34
3.4.6
Motion Transducer Configuration
The Motion transducer on equipped Home Sensor models uses a PIR array sensor for the
detection of human motion in a room. Due to the sensitive electronics used in the PIR motion
detector, the Home Sensor PIR model is designed to behave as follows:
•
For 2 (two) minutes after power is first applied to the device, the PIR motion detector is
disabled. This is required for the PIR transducer output to stabilize and avoids false
detections.
•
For approximately 5 (five) seconds after a radio transmission, the PIR motion detector is
disabled. The operation of the radio causes the PIR transducer to produce false positives
so a ‘cool down’ period is required after each Tx.
The Home Sensor PIR model
before Rev D
is incompatible with Temperature, RH, and Light
Sensing operations (i.e. the corresponding transducers should be kept disabled for proper PIR
operation).
The Home Sensor runs a simple state machine for reporting whether or not motion is detected.
To conserve battery usage, the Home Sensor only reports motion when it is first detected and
when motion has not been detected for a configurable Grace Period.
Note:
The PIR transducer is designed to detected motion so if a room is occupied but the
occupants are not moving, the sensor may report “No Motion” after the Grace Period expires.
Table 3-14 shows a list of Motion transducer configuration registers.
Table 3-14: Motion Transducer Configuration Registers
Address Access Value
Size
[bytes]
Description
0x50
R/W
Grace Period
2
Grace period in seconds (time before
motion is no longer detected)
0x51
R/W
Threshold
2
PIR events before motion is detected
0x52
R/W
Threshold Period 2
Period to count PIR events over for
threshold detection
0x53
R/W
Mode
1
Bit 0: Motion Event Count to Tx
Bit 1: Motion State to Tx
Bit 7: PIR Sensor Enabled/Disabled
Other bits are ignored.