Operation

Technical section 04

How Scentinel balances useful environmental history with cellular availability and power consumption.

Connection strategy

Power management is critical to making Scentinel self-sufficient with its solar panel and battery. Ideally, the device would fully disconnect and enter its deepest sleep state between measurements to save the most amount of power.

Unfortunately, the cellular network makes that approach impractical because too many network reconnects in a short amount of time can result in being blacklisted by the network. Therefore, a dual connection strategy and suitable sleep cycles has been implemented according to the working-week schedule to reach a balance of low latency updates and self sufficiency.

Status

Active | Weekday operation

From 8 am to 5 pm on weekdays, the SoM remains connected to the cellular network and wakes up every 5 minutes to read and transmit data. Between these cycles, it enters STOP mode, allowing for MCU-level sleep without having to repeatedly register with the cellular network.

Low power | After hours

From 5pm-8am, and throughout weekends, the SoM disconnects from the cellular network and enters ULP (ultra-low-power) mode. It wakes once per hour to reconnect and publish a reading before returning to its power nap 😪.

Offline | Missed publication

This status means that the expected publication failed and the device is either offline for maintenance or has been kidnapped.

Machine learning and votes

User votes will provide labels for the gas fingerprints collected by Scentinel. Each vote can be associated with the corresponding ten-channel gas pattern and its environmental context, producing labelled examples for a future training dataset. Combining many votes with repeated gas fingerprints will allow models to learn which patterns are consistently associated with particular events.