2. Define parameters about temperature, system information, disk information, and IP address.

3. Init oled screen, and output init success information from the terminal.

4. Read system information. Display sysinfo-Error on the OLED if it fails, and re-read 0.5s later.

5. Read CPU utilization. There is a sprintf function inside for concatenating strings.

6. Read RAM usage (unit: b). For easy display, it needs to be converted to Mb. Shift the value 20

bits to the right, or written as follows: unsigned long totalRam = sys_info.totalram / 1024 / 1024;