We’ve gotten our hands on some tiny hardware samples from Murata for our LoRa project. These are about a fifth of the size of the previous chips we used. With this tiny hardware it might be possible to create a tracker that’s smaller than a two euro coin – excluding the battery. With a stacked coin cell battery the completed device might actually look like a fat coin. For now we need to get these chips soldered onto a test board.
How do you track with such tiny hardware?
Traditionally a GPS receiver calculates the device’s position. This requires additional hardware; a fairly big GPS antenna and a GPS chip. Additionally getting a GPS fix consumes a relatively large amount of energy. Once the system has a GPS fix, they would send that location over the network. Using the LoRa network the device doesn’t need to know its own location. When the device sends a message, the network calculates where the sender is located.
Imagine you’re blindfolded and someone yells at you. Then you blindly point at that person. You can still point in the correct direction. From the sound you can even guess how far away the person is. Now place multiple blindfolded people around the person who yells. Every person guesses the location of the yell. Combine those guesses and you get a pretty accurate picture of where the yell originated. The LoRa network does something similar. But it uses radio signals instead of sound and antennae instead of ears.