Does blued cache ATT values, and how to clear the cache?

Question

I am trying to find any workarounds for a Bluetooth LE bug on OSX. In particular, I want to know where OSX goes wrong in reading the Bluetooth LE GATT table. Thus, I am view

Answer 1

Yes, blued does cache the Bluetooth LE GATT table. If the cache is bad, do the following to delete it, thanks to “blued process is killing my CPU”:

1. Delete /Library/Preferences/com.apple.Bluetooth.plist. This will remove knowledge of all bonded Bluetooth and Bluetooth LE devices.
2. Kill /usr/sbin/blued. It will be restarted by launchd.
3. Run Bluetooth LE program again. PacketLogger will now show Read By Group Type requests to rediscover the primary services.

Caching is allowed when the central has established a “bond” with the peripheral (not just paired), according to Bluetooth 4.0 Volume 3 Part G Section 2.5.2 Attribute Caching. I’m not sure how to verify that the central indeed bonded with the peripheral, but I assume that it did.