How many bytes can BL65x modules support for Extended Advertising using smartBASIC?

Answer

BL65x modules can support up to 255 Bytes when using extended advertising. This equates to an advertisement packet being sent on one secondary channel.

Extended Advertisement were introduced in Bluetooth SIG v5.0 specification. Advertisement channels 37, 38 and 39 are now qualified as Primary Advertisement Channels with channels 0 to 36 now qualified for use as Secondary Advertisement Channels. Each secondary channel can have up to 255 bytes of payload and the v5.0 specification allows for chaining up to 6 packets for up to 1650 bytes total. However, receiving all of those chained packets may be unreliable resulting in many stack vendors not offering the full chaining capacity.