Introduction - If you have any usage issues, please Google them yourself
* This routine transplant uIP-1.0 protocol stacks, TCP communication demo board and the PC. Customizing a simple application layer
* letter of agreement. This routine function can be achieved:
* (1) PC control LED on the board
* (2) Test TCP and TCP upload speed downlink speed.
* (3) without affecting the communication conditions to achieve the key detection and print key function. .