as S
),
while you pressing the button plug the USB-TTL to your
computer, and then release the button.
3.
Open the upgrade software; select the right COM port according
to your computer shows up. Other settings are default; click next,
if you connect right. You will see a green light on the software.
Then click the next again.
4.
Wait a few second you will see the following picture show up. The
default target will choose automatically, so you don’t need to