Changes

2. The sample file based on the version number is just because different versions of X728 shield use different GPIOs, they are basically the same. You can use a file comparison tool to view it, if you get it wrong, most likely you are using the wrong version of the sample file. You can refer to [[X728-hardware#Pins_and_GPIO_used |X728 hardwar]] to check the PIN occupancy of X728 shield. 3. The sample program is only to demonstrate how to use the advanced functions of the shield, we do not provide the development function of the sample program.