UM0452
Behavior of LEDS and buzzer
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5.2 Application
LEDs
There are three application specific LEDs on the board:
1.
I
2
C LED: This is a green LED (I
2
C) which blinks whenever there is an I
2
C
communication occurring in the application.
Note:
The temperature sensor and RTC are I
2
C based devices.
2.
Alarm LED: This is a red LED (ALARM) which lights up in accordance with the OS
output signal of the TS1 sensor. The behavior of the OS output signal is explained in
Oversaturation alarm in
.
Note:
When TS1 is not selected,
this LED (ALARM) lights up continuously and the alarm LED for
the OS output of TS2 is shown by BUZZ LED.
3.
Buzzer LED: This LED lights up whenever there is a buzzer alarm from TS2.
5.3 Buzzer
There is one buzzer present on the board. This buzzer is attached to the temperature sensor
2 (TS2, TSSOP-8) package.
The operation of the buzzer depends on the polarity set in the configuration register:
●
If the polarity selected in the configuration register is LOW then :
a)
Default state: buzzer sounds
b)
Temperature rises above oversaturation temperature (Tos): buzzer goes OFF
c)
Temperature falls below Thys: buzzer sounds
●
If the polarity selected in the configuration register is HIGH, then:
a)
Default state: buzzer OFF
b)
Temperature rises above Tos: buzzer sounds
c)
Temperature falls below Thys: buzzer OFF