bluetooth midi reconnection (pairing)

[espruino-discuss]

Posted at 2023-04-28 by user155285

Hi,
I am trying to use the puck.js as a BLE midi device ( send and receive)
I am connecting the device with a mac or iphone. The mac systems are not very friendly when it comes to connect a bluetooth midi device, aka you need to go in a menu to connect the device and if the connection get lost you have to redo the all the menu thingy.

Apple documentation states that the device will reconnect itself automatically if the device accept pairing:
https://developer.apple.com/documentation/coremidi/midi_bluetooth/

Is there anyway to use the BLEmidi module but to get the device get pairing also ( like when being HID for example)?

thank you!

[espruino-discuss]

Posted at 2023-05-02 by @gfwilliams

Yes - there are a few options, and one or other of them might work for you...

• You can enable a passkey, which will itself force pairing: http://www.espruino.com/BLE+Security#passkey-pin-pairing
• You can make the Puck try and request bonding with NRF.startBonding: http://www.espruino.com/Reference#l_NRF_startBonding
• I guess you're using the ble_midi module based on your other posts, but if you're calling NRF.setServices yourself like you do in https://forum.espruino.com/conversations/386071/#comment16960253 you can add a 'security' field to the charactertistic (http://www.espruino.com/Reference#l_NRF_setServices) that allows you to say it cal only be accessed over an encrypted connection, which will in turn force the Mac to pair.

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Posted at 2023-05-02 by user155285

Thanks @gfwilliams !
will look at it and report back.
In the meantime I worked on a hot fix using applescript to automatically click the button "connect" if it appears in the bluetooth midi window ::)

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Posted at 2023-05-02 by user155285

I tried all the above, it worked as advertised but didn't resolved or permit the auto-connection ( the device now show in the main bluetooth menu but still need to get connected every time in the bluetooth audio midi setup windows). I assume its coming from the OS side more than the espruino itself.

note: I had a weird behavior with NRF.setServices ( NRF.setSecurity({passkey:"123456", lesc:1, bond :1});)
Where It asked for the passkey only a few restart after and then the Espruino Web IDE will throw random errors when trying to upload new code . had to perform a reset(); save(); to go back to normal.