gounthar

I now want to connect one or two PWM fans (a Delta BFB1012VH 46cfm and a Sunon pf40281bx-d060-s99 24.9cfm). I guess I should use a resistor for the PWM wire, but I don't know about the RPM wire... And should I connect the ground of the fan with the ground of the OrangePi Zero? They don't share the same voltage, so I'm kind of afraid to do so. Any input? Thanks.

Great, thanks a lot to the Armbian team!

Interesting, but not affordable: https://www.cnet.com/tech/computing/facebook-shares-its-time-card-atomic-clock-tech-to-speed-internet-services/

I think that's the plan, getting the time fix with the GPS module, and then use the RTC to keep it vaguely accurate until we get the next GPS time fix. I understood the concept of GPS Holdover and GPS disciplined oscillator, and hope to implement something approaching one of these days.

Interesting, thank you @guidol!

Thank you @guidol, I will have a look at it.

Thanks a lot for these hints, tparys, I do appreciate.

Really interesting, I didn't know I could afford an atomic clock. Thanks.

The problem is it will be difficult to get access to the network where the devices will be. The security is more and more demanding regarding which devices can be plugged into the network (even the guest network), so using the local network is a big no-no for the near future. The requirement for the 1/60th of second precision would be 4 hours or so, so that we can record until the lunch break. We could get another GPS fix during the lunch break. I was thinking of using an ESP32 or RP2040 for that task, but I really know nothing about them, that's why I was thinking of using a SBC running Armbian... which could get input from a microcontroller, as you suggest. Thanks.

I "need" it to be 1/60th of a second precise on several devices not on the same network...

Hi there, let's say I'd like to mimic this device because I'm filming events with several cameras and audio recorders, and that it's really time consuming to synchronize everything before the real editing. So... I was thinking of starting with a GPS module on top of an Orange Pi Zero to get the initial UTC time fix, adding also a temperature compensated crystal to keep it running if we lose the GPS signal (which will happen for sure, as most of my recordings are inside buildings). The goal there is to generate an audio signal thanks to libltc and to add that to the original audio/video in real time. How would you get the GPS+Crystal to set the time for the board? Thanks.

You could maybe just add a newline, or download https://deb.nodesource.com/setup_14.x then add -x on the first line... or change your command line like that: curl -sL https://deb.nodesource.com/setup_14.x | sudo -E bash -x sudo apt-get install -y nodejs This set of commands does work for me.

The thing is I want to be able to incorporate my SBCs in some 19" rack (1 U preferably), in desk grommet, or any other type of enclosure, so I don't want a well designed enclosure, as it won't help me.

No WiFi, no SDCard, M.2 socket, eMMC, SPI Flash, USB-C (power plus host), 4GB RAM, big low profile heatsink, RTC, and GPIO with I2C, SPI, and pins with USB. As small and low height as possible. Options would be NPU, more RAM, CSI and of course a SOM instead of the whole SBC. My $0.02.

But if it is already running Armbian, you could use a swap file with the memory optimizations... I did it on the Zero.