User Manual
HLK-B40
5.2. Quickly verify bluetooth serial transmission
Our company has developed a special mobile phone Bluetooth transparent transmission test APP for this
module for users to use. For APP introduction and instructions, please refer to
HLK-B40 Bluetooth Transparent
Transmission Module Mobile APP Instructions.
Use the module test bottom board and the mobile phone Bluetooth transparent transmission test APP to
immediately start to test and verify the module's serial port-Bluetooth transparent transmission function.
The specific test procedures are as follows:
Connect the module to the test board correctly and connect the test board to the computer through a USB
cable.
Open the corresponding serial port on your computer with the serial debugging tool.
Open the transparent transmission test APP on the mobile phone, the APP will automatically search for
surrounding Bluetooth devices and display them in a list.
Click the Bluetooth device name corresponding to the module in the device list to connect. The default name
of the B40 module is HLK_B40_**** and the suffix is the last four digits of the MAC address.
Figure 8 Figure of transmission test measurement tool
After the app is successfully connected to the module, the connection status LED on the test board will turn on,
means the connected state.
At this time, the data can be sent to the serial port of the module in the serial port debugging tool on the
computer and the sent content will be received and displayed as it is by the mobile phone app;
Send data from the transparent transmission test app on the mobile phone to the module, the sent content will be
received by the module as it is and output to the serial port of the module. The received data can be seen in the
serial port debugging tool on the computer. The effect is as follows: