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Practical LoRaSensorTile Power Usage

A project log for Hackable CMWX1ZZABZ (LoRa) Devices

Useful STM32L082-based devices with embedded LoRa radio modem programmable with the Arduino IDE via USB connector, i.e, hackable.

Kris WinerKris Winer 01/24/2018 at 02:570 Comments

With the availability of the CMWX1ZZABZ-078 Arduino core I have started to write application firmware for the various devices with embedded CMWX1ZZABZ-078 modules and test peak and average power usage as well as sleep current.

Grasshopper sleep current is 2.1 uA, LoRaSensorTile 12 uA, and Cricket Asset Tracker 14 uA.

First test of the LoRaSensorTile in use as an edge node casting BME280 and battery voltage data to TTN every five minutes

TTNdata

shows   peak Tx of 33 mA and average power (at 3V3 input) of ~50 uA. This is with all sensors active (sensor reads once per minute) but the SPI flash is not selected (trying to figure this out now) so I am not actively writing data for logging, but this will affect the average power usage only slightly.

So ~50 uA is about 1.2 mAH per day so with a small 3V3 booster the LoRa SensorTile should last a couple of years on a single AAA battery.

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