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5.9 Bluetooth maximum packet length MTU configuration
MTU is an abbreviation of the communication term Maximum Transmission Unit (MTU), which refers to the
maximum packet size (in bytes) that can be passed on a layer of a communication protocol. This parameter is usually
related to the communication interface (network interface card, serial port, etc.).
The E104-BT51 module supports the long packet standard of Bluetooth 5.0. You can configure the maximum single
packet data length of Bluetooth through the AT command "AT + MTU = xx". 251 bytes by default,27 to 251 bytes
available.Increasing the packet length can realize the large packet data transmission of Bluetooth. For details on setting
command, refer to 6.27 Querying and Setting the MTU Length.
Note: After the packet length is configured, it will take effect on the next Bluetooth connection. Due to some hosts
do not support parameter change requests initiated by slaves, there may be a set MTU length that does not take effect
after connection, which is normal.
5.10 UUID Configuration
The module supports flexible UUID configuration. You can command "AT + UUIDTYPE = 1" to enable the 128-bit
UUID function. You can customize the transparent transmission service UUID, receiving characteristic field UUID,
and sending characteristic field UUID via commands "AT + + SVRUUID = xx", "AT + READUUID = xx", and "AT +
WRITEUUID = xx". UUID, of which xx represents a hexadecimal number. For details on setting method, refer to 6.28
Querying and Setting the UUID Length of the Transparent Transmission Service. This function can solve the problem of
mismatch with UUID of APP communication, meet more custom requirements, and have wider practicability.
5.11 Broadcast data can be switched
The broadcast of the E104-BT51 is divided into general broadcast and iBeacon broadcast. It supports that command
can configure and select the broadcast mode.
General broadcast packet format:
The broadcast information includes advertising and scan respone, advertising is the broadcast message sent actively,
and scan respone is the broadcast message returned after receiving the host scan request.
Advertising
：
Fixed field
Len
Vendor field
Manufa data
020106
N
0xFF
Configurable, Max 26 bytes
