User Manual

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LHT65 Temperature & Humidity sensor 17 / 40
2.7 Read stored sensor data
LHT65 provides 3200 set local data storage feature, user can use AT Commands to retrieve these
data for further analyze.
By default, LHT65 stores one set of data every 5 minutes. LHT65 has reversed 400 sectors for
storage; each sector can store 8 sets data so total 3200 sets of data can be stored. LHT65 use
circle storage method, means the storage position reach the 400
th
sector, it will go back and erase
the 1
st
sector and store from this position.
Below are the AT Commands used to operate these data:
AT+PDTA=start,stop: Print the sector from start to stop.. Example:
AT+PDTA=1,1 will print the first sector (8 set of data)
Explain of the format:
 8019500 is the flash address.
 19/6/3 16:47 is the time
 1 after time means the external sensor type.
 2987 : battery voltage
 sht_temp and sht_hum are the built in sensor temperature and humidity.
 ds_temp is the external sensor value.
AT+PLDTA: will print the most recent few sets of data. Example:
AT+PLDTA=10 will print the latest 10 sets data