OY1700 LoRaWAN Air quality (PM) sensor, User manual, Version 0.1
15
8.3.2.2
Relative humidity conversion
The relative humidity (RH) measurement is transmitted using an unsigned 12-bit value. The
scaling is 1/10 % RH and the offset is 25 % RH, which means the received value should be
subtracted by 250 and then divided with 10 to get it in % RH.
8.3.2.3
Particulate Matter (PM) conversion
The Particulate Matter of different sizes PM10, PM2.5 and PM1.0 are measurement in parts-
per-million (ppm – 1 x 10
-6
), is transmitted using an un-signed 16 bit integer.
8.3.3
Example: Measurement report
Measurement data is sent on LoRaWAN port 2
3e 44 1d 02 1b 01 34 01 12
(3e1)
HEX
: (993)
DEC
=> 993/10 -80°C => 19.3 gradC
(44d)
HEX
: (1101)
DEC
=> 1101/10 – 25% => 85.1 % RH
(021b)
HEX
: (539)
DEC
=> 539 ppm PM10
(0134)
HEX
: (308)
DEC
=> 308 ppm PM2.5
(0112)
HEX
: (274)
DEC
=> 274 ppm PM1.0
