User's Manual

Chengdu Ebyte Electronic Technology Co., Ltd E104-BT5032A User Manual

1.3 Application

 Smart home and industrial sensors;

 Security system, positioning system;

 Building automation solutions;

 Wireless remote control, UAV;

 Wireless game remote control;

 Healthcare sensor;

 Wireless voice, wireless headphones;

 RFID;

 Automotive applications.

2. Operation Notice

2.1 BLE knowledge

This chapter mainly focus on BLE knowledge.

2.1.1Connection interval, advertising interval and scanning interval

In order to ensure low power consumption, BLE adopts interval working mode.

The scanning interval is to scan the advertising channel every certain time. The smaller the scanning interval, the higher the

average power consumption during scanning, but the faster the slave device is found.

The advertising interval is that the advertising is released every certain time. The smaller the interval, the easier the slave device

will be found by the master, and the higher the average power consumption.

For a connected BLE device, the master initiates a request to the slave every certain time (connection interval), and after

receiving the request, the slave responds to the request of the master at the same time (connection interval). If the slave does not

respond to the master request within the specified time (connection timeout), the master judges the slave to disconnect, while the slave

fails to receive the request of the master within the prescribed time (connection timeout), and the slave judges that the master is

disconnected connection. In order to reduce BLE power consumption again, the BLE protocol also stipulates that the slave can ignore

requests for a specified number of times (slave timeout). The smaller the connection interval, the greater the data throughput, but the

greater the power consumption. When users are concerned about data throughput, the connection gap can be reduced. Note that with

regard to the connection interval, the connection interval between different devices may be different and cannot even be changed, such

as the iPhone.

2.1.2 MTU

Refer to the effective size of the BLE air single packet data. The MTU in the ble 4.0 / 4.1 protocol is 27 bytes, which can be

expanded from ble 4.2 and higher to 251 bytes.

When the MTU is actually used, the user's effective load is reduced by a 3-byte header. This means that the single packet data for

4.0 / 4.1 users is up to 24 bytes, and the single packet data for ble4.2 and later versions is up to 247 bytes.