Users Manual

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LSN50 LoRa Sensor Node User Manual 36 / 55
2. Sampling current while reading DS18B20 and Oil Sensor
● Oil Sensor sampling time: 200us, current: 0.3mA
● DS18B20 sampling time: 750ms, current: 0.64mA
● Above power should add 8mA CPU power in working mode.
3. LoRaWAN transmit and receive time consumption. The LoRa TX / RX time and power
can be found in the LoRa calculator tool.
In a typical LoRaWAN data transmit. The energy profile is as below:
In the LoRaWAN protocol, the device will transfer in different LoRa Radio, and have different
energy profile in LoRa part. We can calculate the battery life in two cases:
1) Lower power LoRa radio. Device has a good signal to gateway
2) Higher power LoRa radio. Device has a poor signal to gateway
Low Power Case:
● Radio Parameter: SF7, 125kHz, 20dbm
● Transmit interval: 15 minutes.
● Payload: 8 Bytes.
High Power Case:
● Radio Parameter: SF10, 125kHz, 20dbm
● Transmit interval: 15 minutes.
● Payload: 8 Bytes.
To simplify the calculation, we can:
● Combine oil sensor and DS18B20 sampling energy together to 751ms@8.64ma
● Combine the two RX windows together.
There is a power consumption tool for easy analysis. Below is the analysis result.