BULK COMMAND AUTOMATION FOR GPS DEVICES

GPS trackers in the field are configured through SMS commands. Four different brands are in use (WanWayTech, Teltonika, Armoli, Dahua) and each speaks its own command syntax. Reconfiguring hundreds of devices meant a technician texting them one by one from a phone and waiting for replies: slow, error prone, and impossible to audit afterwards.

You upload a spreadsheet, pick a command, and the system composes the right command text for each device model itself, sends them in order, and matches up both the operator’s delivery report and the confirmation SMS the device sends back.

The key decision was moving dispatch into a separate worker process: a queue that moves at one SMS per second, a timeout sweep, and an hourly automatic retry. The interface never blocks, and an interrupted job is not a lost one.

The SMS gateway sits behind an abstraction — today it runs over httpSMS with an Android phone; moving to a carrier API later is one class. A mock gateway lets the whole flow be tested without a phone at all.