Set up different wifi

I am using the image for my own project. I am wondering how to disable the default wifi and set up my own wifi? I tried to creat a new wpa_supplicant.conf under /etc/wpa_supplicant. However, sometimes the pi still connects to the default wifi. Is tehre a way to do it? Thanks.

I found one earlier post referring to And solved my problem. Thanks.

We continuously enhance the site as time goes on.
All users of our product should be aware of and refer to that site.

Thank you for posting that you found a solution which no doubt was to disable our pifi solution.
We have been rather busy lately and sorry that we had not gotten back to you for your question.