Honeywell HIH-6130 Series Technical Note

Technical Note
Using Alarms on the Honeywell HumidIcon™ Digital
Humidity/Temperature Sensors: HIH-6130/6131 Series
1.0 Introduction
The Honeywell HumidIcon™ Digital Humidity/Temperature
Sensors: HIH-6130/6131 Series support up to two configurable
alarm outputs which can be used to monitor whether the
ambient humidity has risen or fallen below preprogrammed
values. The alarms have configurable thresholds, polarity and
outputs to provide flexible interfacing with other components.
This document describes:
Alarm functionality
Configuration options
2.0 Alarm Output
The alarm output can be used to indicate whether a predefined
humidity level has been reached. The alarms can be
configured in two ways:
As an open-drain output to drive a load connected to V
(see Figure 1).
Figure 1. Alarm Open Drain Output Application Circuit
Example
Digital Humidity/
8
V
DD
0.22 µF
1
V
CORE
0.1 µF
2
V
SS
7 NC
GND
As a full push-pull driver for interfacing with a
microcontroller or to drive a high voltage external device,
(see Figure 2).
Figure 2. Alarm Push-Pull Output Application Circuit
Example
Digital Humidity/
Temp. Sensor
8
V
DD
0.22 µF
1
VCORE
0.1 µF
2
ALARM_LOW
V
SS
7 NC ALARM_HIGH
GND
Sensing and Control
How to combine alarms
How do disable alarms
V = 2.3 Vdc to 5.5 Vdc
SUPPLY
Temp. Sensor
SCL 3
SDA 4
6
ALARM_LOW
5
ALARM_HIGH
V = 2.3 Vdc to 5.5 Vdc
SUPPLY
12 V
12 V
3
SCL
SDA 4
6
GND
5
GND
If available, both alarms can be used at the same time. The
alarm outputs are updated when a measurement cycle is
completed.
3.0. Alarm Functionality
There are four registers associated with the alarm thresholds
(see Appendix A for the EEPROM addresses):
Alarm_High_On
Alarm_High_Off
Each register contains a 14-bit value that determines the
humidity at which the alarm turns on or off. The two
Alarm_High registers set the hysteresis of the Alarm_High pin,
while the two Alarm_Low registers set the hysteresis for the
Alarm_Low pin (see Figure 3).
Figure 3. Alarm Hysteresis
DD
High Alarm On
Alarm_Low_Off
Alarm_Low_On
NOTICE
Alarm registers may only be accessed using Command
Mode. (See Technical Note
Mode on Honeywell Digital/Temperature
Alarm_High_On register determines the humidity
threshold where the high alarm is activated.
Alarm_High_Off register determines the humidity
threshold where the high alarm is deactivated.
Alarm_Low_On register determines the humidity threshold
where the low alarm is activated.
Alarm_Low_Off register determines the humidity threshold
where the low alarm is deactivated.
Alarm_Low_On
Alarm_Low_Off
Alarm_High_On
Alarm_High_Off
High Alarm Off
Low Alarm Off
Low Alarm On
Time
"Entering and Using Command
Sensors".)