Kona Home Sensor TRM
T0005370_TRM
Version Rev-C 1.0
TEKTELIC Communications Inc.
Confidential
Page 26 of 34
3.4.5
Light Sensing Configuration
In all Home Sensor modules
before Rev D
, Light Sensing is only compatible with the Base and
External Connector models, and should be kept disabled for the PIR model.
The Home Sensor Light sensing allows for the presence or absent of light based of the built-in
light sensing transducer. The sensing element light pipe is visible on the top surface of the
Home Sensor. The orientation of the Home Sensor relative to the light source impacts the
measured level of light intensity. Table 3-12 shows a list of Light transducer configuration
registers.
Table 3-12: Light Transducer Configuration Registers
Address Access Value
Size
[bytes]
Description
0x47
R/W
Sample Period 4
Sample period of the light transducer (seconds)
0x48
R/W
Threshold
1
Threshold from 1 to 64 (darker to brighter)
The Light transducer is held turned off to preserve energy. Whenever light data is needed, it
gets turned on by the MCU.
3.4.5.1
Sample Period
The light sensing sample period determines how often the light sensing transducer is powered
on and checked for the presence of light. Shorter sample periods result in an improved
detection time but result in additional battery usage.
Acceptable values for the sample period are 0, 10, 11, 1
2, ….
Setting the sample period to 0
(zero) disables the light sensing element. Setting the samples period to anything from 1 to 9
sets the sample period to 10.
Note:
The light sensing sample period needs to be enabled for periodic transmission.
Otherwise, in every transmission a repetitive light value residing in the MCU memory is
reported.
3.4.5.2
Threshold
The Light Threshold is used to set the dark/bright transition point for the Sensor. The Home
Sensor only transmits when the threshold is crossed, and when first enabled, begins in the
‘dark’ state. A threshold setting of 1 (one) corresponds to the darkest threshold.