K2S firmware update 2019.8.27

1, revise a file name bug

2, revise GPS log bug

3, revise speed stamping bug

4, update GPS tester UI

5, update service link

<download here>

K2S firmware update 2019.6.19

added 256GB card support

fix small bugs

<download here>

K2S firmware update 2019.5.20

added speedcam function

<download here>