nRF52832
www.szrfstar.com V1.3 - Sep., 2020
Shenzhen RF-star Technology Co., Ltd. Page 17 of 58
4 UART Transparent Transmission Protocol (Bridge Mode)
The bridge mode means to set up a bi-directional communication way between user CPU and mobile devices by the
mutual connection between serial port and user CPU. Users can reset serial port baud rate and BLE connection interval
by the specified AT commands (see the section “AT Command”). The module will have different data handling capability,
as per different serial port baud rates and BLE connection intervals. The default baud rate is set at 115200 bps.
Except for Beacon mode, the serial port is open by default in any mode. If this function needs to be closed, please use
the "AT+SLEEP=1" command to close the serial port.
The module can customize the serial port package according to the acquired MTU of the connected device. According
to the packet size, the packet will be sub-packed automatically and sent, with a maximum load of 244 Bytes for each
wireless sub-packet. Data packets from mobile devices to the module must be sub-packed automatically (into 1 ~ 244
Bytes/packet) before sending. The module will transmit them to the master RXD in turn, when received the packets.
1. The hardware protocol of serial port: 115200 bps, 8, no parity, 1 stop bit.
2. For reliable transparent transmission, please use flow control. Most of the serial port tools of PC-side do not have
CTS detection. It is recommended to use the software SecureCRT.
3. After the module is connected, BRTS needs to be pulled low if the master (MCU) has data to send to the BLE
module, and the data transmission can be started around 50 ms afterwards. BRTS should be pulled high by the
master after transmission finished and make the module exit the serial RX mode. Pay attention to that there will be
a delay after the data is transmitted, and confirm that the data transmission has been completely finished before
BRTS is pulled-high. Otherwise there will be data truncation.
4. When there is data upload request, the module will set BCTS low and start to transmit as soon as 500 μs, until data
transmission finishes.
5. If the mater BRTS is being kept a low level, the Bluetooth module will always be in serial port receiving mode and
the power consumption will be high.
To Next Page
Loading...
Need help?
General