RE: If you change preferred PHY, does bluetooth connection break?

FormerMember — Fri, 17 Feb 2017 13:48:46 GMT

The PHY can be changed while in a connection (Bluetooth Core Specification v.5.0, Vol 6, Part B, chapter 5.1.10):

The PHY Update Procedure, when supported, is used to change the transmit or receive PHYs, or both. The procedure can be initiated either on a request by the Host or autonomously by the Link Layer. Either the master or the slave may initiate this procedure at any time after entering the Connection State. Link Layer PHY preferences may change during a connection or between connections and, therefore, they should not be cached by the peer device.

To change PHY, the function sd_ble_gap_phy_request(..) can be used. The preferred PHY can be set using sd_ble_opt_set(..).