HF-BL200A Low Energy Bluetooh
(
BLE 4.1
)
Module User Manual
Shanghai High Flying Electronics Technology Co., Ltd www.hi-flying.com
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3. UART TRANSPARENT TRANSMIT MODE
3.1.
Transparent Transmit Mode
Transparent Transmit means the two way communication between device and mobile terminal via
the connecting with serial interface and device MCU. Device can set HF-BL200A baud rate and
connect interval via AT command through serial interface (refer to
“ Serial AT command
Description
” for details). Target different baud rate and BLE connect interval or different packet
sending interval, module would have different data handling capacity. The default baud rate of HF-
BL200A is 115200bps, it is recommended to set baud rate at 115200bps when transmitting big
data or in highly real-time application. Baud rate support save after power off.
Figure 6.
Basic HF-BL200A wireless network structure
Module BLE connect interval is 20ms, and it is able to send almost 200 byte data one time via
serial interface. Theoretically, module is able to send data up to 4KB/S. Below is the detail description
about transparent transmit.
Module can receive almost 200 byte data from serial interface one time. Module will automatically
send sub-packet according to data size, each packet limit is 20 bytes. The data packet sending from
mobile device to module must be separated to sub-packet(1-20 byte each). After receiving the sub-
packets, module will send to MCU in proper order.
Serial hardware protocol: 115200 bps, 8,non-parity, 1 stop bit
After receiving data from MCU serial port, module will judge if it is AT command. If it is, module
will execute the command. If not, module will transmit the data to APP under BLE connection and
notify mode enabled status.
After module receives APP data, it will output the data to MCU via serial interface.