I have Telemetry beacons and a Raspberry 3 with bluetooth.
I managed to read data from the beacons broadcast using Node + Noble library.
I managed to control the GPIO port state (high/low) using the Estimote App.
I managed to update beacons settings using the Rest API with Node + Axios.
But I have no clue how to control the GPIO from a Raspberry: is there any sdk for any other platform than iOS/Android in any language that I can use?