Bluetooth low energy event packet tws portable wireless speaker

The event packets sent by the controller to the host are mainly used to send information and feedback previously entered commands. The HCI event packet consists of an event type code, a parameter's length field, and an event parameter. Each event has a unique set of parameters. bjbjaudio.com

Bluetooth Low Energy mainly has the following three basic event types;
Generic command completion event
Generic Command Status Events
Specific command completion events bjbjaudio.com

1. Generic command completion event
When the command sent by the host to the controller is completed, the controller immediately returns a general command completion event. The parameters of the event contain the previously sent command opcode and the return parameter of the executed command. The first parameter in the returned parameter is the status code, which is used to indicate whether the command is executed successfully or not. For example, LERand is used to command the controller to return a random number. It has two return parameters, one is the status code and the other is the random number returned. Note that the generic command completion event is used whenever the controller performs a task not related to wireless transmission. For example, the LEEncrypt command does not involve link-layer packet transmission, so a generic command completion event will be returned. The LE Create Connection command requires at least one link layer connection request packet (CONNECTREO) to be sent before the connection is established, so a generic command completion event will not be returned. bjbjaudio.com

2. Generic Command Status Events
Command types such as LECreateConnection mentioned in the previous section need to perform wireless transmission operations, and usually return a general command status event; a specific command completion event will be returned after a period of time. bjbjaudio.com

3. Specific command completion event
Some commands take a while to complete execution, and they all have corresponding, and are the only, specific command completion events. For example, the LECreateConnection command first returns a command status event, then waits for the connection to be established or fails before returning the LEConnectionComplete event. It should be noted that whether the command is completed is not marked by the receipt of a specific command completion event. bjbjaudio.com