Topics: Alert, JSONata, Advanced Sensing
The presenter shares a new anti-theft tracker inspired by how thieves actually steal the beehives for honey and abandon them afterwards. The hardware used in this tracker is the cellular note card, the cellular note carrier for it to live on, and a lipo battery to power the whole thing. When the note card is configured like a tracker and motion is detected, it will start sending its current GPS coordinates every minute to the blues wireless note hub cloud, and the note hub can integrate with things like Twilio and send that data as an SMS alert to the user’s phone. In a typical note card tracking event, much data is involved, like data about the note card itself, the device the product belongs to, the body, which is the primary information, and the location of where this note was taken. The essential data for the user are the latitude, the longitude, the time stamp, and the note card serial number. The note hub route uses JSONata expressions to filter down to a particular type of note card and also filter out the types of events to send. In the case of Twilio, the note hub, using JSONata, pulls out the relevant data from the actual event and formats it to the shape that the Twilio API expects, which includes a Twilio phone number, which is the user who’s receiving it. Then it also receives the body of the message itself. Instead of just giving the latitude and longitude of the location, the alert message consists of a google maps link which takes the coordinates as input and opens the exact location of the device on the map, which is much easier to work with and view on a smartphone.
The alert message is only sent when the motion is detected, including the name of the note card, where it was last spotted, the time frame, and then the google maps link. Every time the note card detects motion and keeps detecting motion, it sends alerts every one to two minutes. People can also use this tracker system to create their own tracking solutions. There is an hackster article which includes all the details from configuring the note card to setting up accounts in note hub and Twilio, the testing and debugging of JSONata expressions. The most challenging part of building this system was getting the jsonata expressions right between the documentation on dev.blues.io and setting up my note card.