CS-Student.com

Author: Felix Tang

  • NTP Synchronization problem in NTP server

    Felix Tang

    When the GPS receiver is turned off for a day and then powered back, you will find the GPS receiver works fine by typing Type the “ntpq -p” and return messages becomes This means NTP server cannot sync the time with GPS receiver. Check with /var/log/ntp.log, you find The error message “SHM: difference limit exceed,… Read more

  • Create web interface for NTP server – install NodeJS, Express and MySQL (Part 1)

    Felix Tang

    The NTP server hardware has been properly assembled, connected, and configured to function correctly. The detail can be read at the following URL link: https://cs-student.com/create-a-ntp-server-using-orange-pi-zero-2-and-gps-receiver/ Next, I plan to develop a web interface for adjusting the IP address and time, as well as for monitoring the received satellite information. Let’s start ! (1) Install Node… Read more

  • Create a NTP server using Orange-pi Zero 2 and GPS receiver

    Felix Tang

    In my previous post, I outlined the steps to create an NTP server using a Raspberry Pi 4B and GPS receiver. However, the cost of a Raspberry Pi 4B with a LAN port is quite high. Therefore, I decided to switch to the Orange Pi Zero 2, which can reduce costs by one-third. The steps… Read more

  • Create a NTP server using Raspberry-pi and GPS receiver

    Felix Tang

    In this project, a Raspberry Pi 4B is connected to a Neo7 GPS receiver via a USB cable to obtain GPS data, particularly the time information. The Raspberry Pi will then be configured as an NTP server for other IP-based devices. Real ApplicationIn a secure CCTV system, all components, including cameras, network switches, and NVR… Read more

  • Create a VPN server using Orange-pi, Ubuntu and SoftEther VPN software

    Felix Tang

    SoftEther VPN, which stands for “Software Ethernet,” is one of the world’s most powerful and easy-to-use multi-protocol VPN software solutions. It can provide concurrent VPN connections and supports a variety of operating systems, including Windows, Linux, Mac, FreeBSD, and Solaris. Developed as part of Daiyuu Nobori’s Master’s thesis at the University of Tsukuba, SoftEther VPN… Read more

  • Email notification : Public IP address of a broadband router

    Felix Tang

    Many home and small business internet connections use dynamic IP addresses that can change periodically. This makes it challenging to reliably access services (such as a web server or home network) hosted on that connection, as the IP address changes over time. Dynamic DNS (DDNS) is a valuable technology that provides reliability, remote access, and… Read more

  • A chart showing recording size of IPCAM using Ajax & Express

    Felix Tang

    The size of IP camera recording can be significantly influenced by various factors, including configuration settings such as encoding method (H264, H265), bit rate, and video size, as well as environmental conditions like lighting, video noise level and the moving speed of recorded objects. To visually represent these variations, I intend to utilize a line… Read more

  • Blog post loading on web page with Ajax & Express

    Felix Tang

    Create a static page called blog.html in the public folder. Content of the server7.js The appropriate file structure should resemble the following: Run the Express application by executing the following command in the Ubuntu terminal: Make sure both Orange Pi and PC have the same subnet and connect to the same router or network switch. On the PC’s web… Read more

  • Rotating Photo gallery on web page with Ajax & Express

    Felix Tang

    Create a static page called gallery.html in the public folder. JavaScript inside sends an AJAX request when the the page is loaded, and every 2s after, to the route for the path /images.json. When the AJAX response is received, use the response data to Content of the server6.js The appropriate file structure should resemble the following: Run the Express… Read more

  • Dynamic content loading on web pages with Ajax & Express (5)

    Felix Tang

    It is the fifth example using JQuery AJAX function and Express JS. This example sets up a disclaimer page for user to accept to use of cookies. The work flow of disclaimer.html Content of the server5.js The appropriate file structure should resemble the following: Run the Express application by executing the following command in the… Read more