A: it is recommended that you purchase at least 2pcs or more for the first time to facilitate testing. After purchasing the module, 

our salesmen will provide you with a set of information packages, including manuals, upper computers, packaging libraries and 

other information.
After receiving the module, it is strongly recommended that you first connect the module with USB to TTL, and then separately 

supply 5V power to the module. Use the computer and the upper computer provided by the data package to conduct 

communication test and familiarize yourself with the protocol. After the test meets the requirements, the product can 

communicate with MCU.