This is for UART version of Bafang Motors only.
 
Use this cable to connect to your computer to fully customize the motor and set parameters. 
*Requires to download the free programming software of your choice
I recommend this:
https://penoff.me/2016/01/13/e-bike-conversion-software/
or this:
https://github.com/danielnilsson9/bbs-fw/blob/master/README.md
 
I also recommend this guide for programming:
 
https://electricbike-blog.com/2015/06/26/a-hackers-guide-to-programming-the-bbs02/