Well, my initial plan when buying the t-beam with gps was to some day get it mounted on my car’s roof, probably still with it’s own battery, charging via usb every now and then.
But thinking about it further (nothing else to do while driving ) - i realized that there could be another benefit from having an external gps(antenna): replacing my phone’s gps with it, like in the old days … remember ‘GPS mice’?.. i can’t help, but gps in car still sucks quite often after all these years.
And well, the ESP32 got BT/BLE, so hey - this can’t be that hard … can it? Turns out it isn’t as easy as i hoped, as there doesn’t seem to be any openly available code doing just that, but there’s a lot of information which should make it possible to piece it together relatively easy… i’m still in early stages of researching and testing, but thought i’d put my links together in here, and maybe someone would like to follow along and/or cooperate/contribute. For sure this would make it a bit of a different ttnmapper-app, and probably one could also add some other fancy stuff like configuring channel/SF from the phone.
so, what’s the goal:
- the ttgo t-beam either in a housing on the car roof, or inside with an antenna like this
- receiving gps and doing it’s lora/mapping-stuff as always
- but at the same time acting as a BT/BLE-service for location
- which one can connect one’s phone or other devices to
what i’ve found so far:
findings by our guy with the swiss accent https://www.youtube.com/watch?v=osneajf7Xkg
definition of the “location and speed characteristic” in BLE https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.location_and_speed.xml
which should make it possible to put the lat/long into the right format
the library in the platformio repo #1841 (yes, i’ve actually gone completely platformio now)
an instructable including a simple android app to communicate with an esp32 https://www.instructables.com/id/ESP32-BLE-Android-App-Arduino-IDE-AWESOME/
basic tutorial for UART via BLE
probably essential app for testing BLE stuff https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp&hl=en
only tested the UART example included in the library so far, which lets me connect, but only sends rubbish (like wrong baud rate on serial port), didn’t debug yet.