IoT For Final-Year Projects: Choosing A Protocol That Fits
By Educraftech
Nearly every student IoT project starts on Wi-Fi, because Wi-Fi is what the laptop uses. It is a reasonable default for a mains-powered device sitting in a lab. It is a poor one for anything battery powered or more than a room away.
Three questions decide it
How far does the signal need to travel, how long must the device run on a charge, and can you afford a gateway? Those three answers narrow the field faster than any comparison table.
Where each one fits
Wi-Fi suits mains-powered indoor devices where an access point already exists. BLE suits short range and long battery life where a phone is the gateway. LoRa suits kilometres and years on a battery when the payload is small and infrequent. Zigbee and Thread suit dense meshes of many low-power nodes.
Budget the radio, not the average
A radio that draws 120 mA while transmitting for 200 ms every minute is not a 120 mA device. Work in charge per hour, not peak current, or the battery estimate will be wrong by an order of magnitude.
Test at the edge, not the bench
Link quality on a desk tells you nothing about link quality through two walls. Measure at the worst position the device will ever occupy.