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LHT65 Temperature & Humidity sensor      20  /  56 
 
2.4.11 Ext=7, Counting Sensor 
In this mode, user can connect external interrupt sensor to the E2 Extension Cable for 
counting purpose. Whenever there is an interrupt from this sensor, the ext value will 
increase by 1.     
(NOTE: This feature only supported by SN number > LHT65307029) 
 
 
 
Above is connection to a mercury switch, rotate the mercury will generate interrupt. LHT65 
will count it. It will periodically the counting value to server. User can also connect PA9 and 
PA10 together, with these two pins shortcut, LHT65 will know if the probe is connected well 
in the socket.   
 
User can use AT Command to set the method to detect counting: