10
sensitivity of the system. Using an internal LDO increases sensitivity, but system power
consumption will be slightly higher.
4.2 Precautions
To ensure the module's RF performance in the application of its maximum possible
effectiveness, the user should follow the following principles:
1. It is recommended to supply the module with DC power supply. The power supply ripple
coefficient should be as small as possible. The module should be reliably grounded. Please pay
attention to the correct connection of positive and negative poles of the power supply. If the
connection is reversed, the module may be damaged permanently.
2. Module recommendations placed on the edge of the floor open space, the antenna should be
outward;
3. The module under the antenna PCB (double-sided board and multi-layer board) need
clearance, can not be deposited copper, that is all the layout layer below the antenna can not
have grounding or signal trace;
4. It is better to keep metal parts away from the antenna, or module communication distance in
different environments will be shortened at different degrees. Please refer to recommended
locations in following figure:
Figure4: Module recommended placement
4.3 Download and Debug
The module supports the ARM serial wire debug (SWD) port, the SWD port pin is
DIO9(SWCLK),DIO10(SWDIO).Through J-link or ST-LINK, you can download and debug.
When the module is power up or hardware reset, if DIO7 is high, you can enter the boot mode,
the module is not available at this time, the module can be programmed through the serial port
code.
4.4 Development board
Refer to LSD1RF-EVBGP001 data.
4.5 Reference manual
