Espruino Hub installed OK, but Bangle connect fails often

What's the unexpected response you're getting?

// This is a DataView, but:
{"buffer":[72,101,108,108,111,32,87,111,114,108,100,33,10],"byteOffset":0,"byteLength":13}
// Converting it to a String gives:
var dv  = {"buffer":[72,101,108,108,111,32,87,111,114,108,100,33,10],"byteOffset":0,"byteLength":13};
print(E.toString(dv.buffer))
// Hello World!

Could the Softdevice error BLE error 0x11 (BUSY) error be because you might have been trying to connect when a device was already in the process of connecting? That does seem a bit strange.

But in general you would expect the connection to fail sometimes, especially as you'll be connected to Bangle.js via Bluetooth already so it's trying to juggle connecting, but also doing communications with the host PC at the maximum datarate it can handle.

Also Bangle.js's bluetooth range isn't actually that great, so I guess that could cause you issues as well.

I'd be interested to know whether it's actually any more reliable when you're not connected by PC, or if you run NRF.setConnectionInterval(100) to force bangle.js to use a lower-datarate connection to the PC (the default is NRF.setConnectionInterval(7.5))