I’ll never be late again - Open Timecard Mini

Summary

The video script discusses the importance of accurate timekeeping in computers, especially in large networks. It introduces two products: the Time Card Mini and the G0 KK (Gawk), which use GPS to achieve time accuracy down to 0.03 seconds per year. These devices connect to satellites for precise time data and output it through a Raspberry Pi. The script also covers setting up a time server using these devices, addressing initial technical issues and achieving synchronization with public time servers. The result is a local time server with remarkable accuracy, demonstrating a fun and advanced solution for time synchronization.

Takeaways

• ⏰ Time synchronization is crucial for computers, especially in large clusters, where all machines must stay in sync.
• 🖥️ The Time Beat Time Card Mini and G0KK (Gawk) are specialized devices designed to provide highly accurate time synchronization for computers using GPS data.
• 📅 Most computers have real-time clocks, but they can drift by seconds per day, which can be problematic for precision applications.
• 📡 The Time Card Mini connects to satellites (GPS, GLONASS, Galileo) to get precise time data, which it relays to a Raspberry Pi or other systems.
• 📈 The SI T 5811 chip included in these devices can maintain time accuracy within one part per billion for up to 8 hours.
• 💻 The Ethernet connection allows the time card to be integrated into existing systems, sending time signals through the network without needing a new rack or system.
• 🕒 In a Linus Media Group project, the Time Card Mini was used to set up a precise time server, which was essential for syncing computers in a cluster.
• 🔄 The Raspberry Pi kernel used to run the time sync software had issues with simultaneous GPS serial and PPS data, but a fix is in progress.
• ⚙️ Proper setup can lead to nanosecond-level accuracy, with occasional minor offsets caused by the hardware and software configuration.
• 🔧 Although precise time synchronization is not always necessary, it's a fun and interesting project, particularly for those working with clusters or requiring high precision.

Q & A

Why is time synchronization important for computers?

Time synchronization is crucial for computers, especially when multiple computers need to communicate or perform tasks in sync. It ensures that all systems are working with the same time reference, which is essential for operations that require precise timing.

What is a real-time clock (RTC) and why might it not be accurate?

A real-time clock is a hardware clock found on computer motherboards that keeps track of the current time. However, it may not be highly accurate as it can drift by several seconds per day due to the inherent inaccuracies of the clock hardware.

How does the Time Card Mini help improve time accuracy?

The Time Card Mini uses a GPS chip to connect to GPS and other satellite systems like Galileo to receive very accurate time data, which it then outputs to a connected Raspberry Pi, significantly improving time accuracy.

What is the purpose of the u-blox M8F0 GPS chip on the Time Card Mini?

The u-blox M8F0 GPS chip is used to receive accurate time data from GPS and other satellite systems. It sends a pulse at the start of every second, which helps to synchronize the system time with high precision.

What is the function of the PCIe card mentioned in the script?

The PCIe card is used to provide power to the Time Card Mini. It allows for the addition of a powerful and accurate time server to existing infrastructure without the need for significant hardware changes.

Why did Linus Media Group set up a time server using the Time Card Mini and gawk One Mini?

Linus Media Group set up a time server to meet the precise time synchronization requirements of their Proxmox cluster setup, which needed time sync within about 5 milliseconds.

What is the issue with the Raspberry Pi's kernel code as it relates to the Time Card Mini?

The kernel code has an issue handling both the GPS serial connection (NMEA) and the PPS (Pulse Per Second) at the same time, which can cause instability. The Time Card Mini's manufacturer is aware of the issue and is working on a fix.

What is the significance of the PPS signal from the GPS chip?

The PPS signal provides a highly accurate time reference, with the potential to achieve synchronization within nanoseconds, which is essential for applications requiring precise timekeeping.

Why might using a public time server as a primary clock source be problematic if the internet goes down?

If the internet goes down, a public time server as a primary clock source would not be accessible, potentially causing synchronization issues. However, the GPS chip would still provide accurate time data, though without the internet, the system would lose the ability to sync with the actual time.

How accurate is the time synchronization achieved with the Time Card Mini and gawk One Mini?

The time synchronization achieved with these devices can be within 10 nanoseconds, which is extremely accurate and suitable for high-precision applications.

What is the practical use of such accurate timekeeping for a typical user?

While most users do not require such precise timekeeping, it is essential for specific applications like scientific research, financial trading systems, or any system that requires highly synchronized operations across multiple devices.