BC66 with STM32Nucleo64

When i connect BC66 module with STM32 Nucleo 64 via arduino uno. Follow in document, when connect them, need remove the two 0Ω resistors (SB13 and SB14) by soldering iron, and then solder them onto SB62
and SB63 respectively. Why should i do that?

hi, Anh_Phuc:
Do you operate according to the design scheme we provided?
Replacing the corresponding resistor is mainly to match the voltage between BC66 and MCU.
Or refer to the following design in our manual.

Quectel_BC66_Reference_Design_V1.1.pdf (352.3 KB)

Now, i want to connect two this board to send ATCommands from MCU to BC66. So, what do i need? Can you give me some relate document, pls

hi, Anh_Phuc:
I’m sorry that I don’t have relevant documents about sending instructions to modem through MCU. There is only a manual for sending AT Command through serial port. I guess you have this manual already;
Quectel_BC66&BC66-NA_AT_Commands_Manual_V2.2.pdf (760.6 KB)