how to download recorder gpx automatically/automation?

Ok, well, this bit is what you need then I think: https://github.com/espruino/EspruinoHub#connections

So...

• When you get presence detect on the bangle, start sending /ble/notify/MAC_ADDRESS/nus/nus_rx once a second
  
• Start listening for /ble/data/MAC_ADDRESS/nus/nus_rx topics
  
• Now send JS code to /ble/write/MAC_ADDRESS/nus/nus_tx - maybe something like require("Storage").list("recorder.",{sf:true}) that'll output the list of available Recorder files
  
• You might want to tag it so you can easily separate the response from other messages, for example by sending the actual string: '\x10Bluetooth.println("FILES="+require("Storage").list("recorder.",{sf:true}))'
  

• Once you want a file, you just need to send the JS code to output it. So for example maybe:

  (fn=>{
  Bluetooth.println("==== START FILE "+fn+"====");
  var l, f = require("Storage").open(fn,"r");
  do Bluetooth.print(l=f.readLine()); while (l);
  Bluetooth.println("==== END FILE  ====");
  })("recorder.log0.csv");
  

Then hopefully you can receive all those responses via the /ble/data/MAC_ADDRESS/nus/nus_rx topic and you're good :)