121–130 of 188 posts
These timing cards are low volume products so they have a bad habit of going out of support after a few years and then the kernel level drivers don't get updated and there is hardly any community. Having open hardware that multiple vendors can support makes them easier to get added to the mainline kernel.
> While building our Time Appliance, we also invented a Time Card, a PCIe card that can turn any commodity server into a time appliance. Invented? These cards have been around. e.g. Meinberg makes a variety of expansion cards which use various time keeping sources such as WWVB, IRIG-B, GNSS, etc.
Please excuse the language “invented”. We simply meant “came up with a form factor” of having the MAC+GNSS present via PCIe bus as a POSIX clock similar to a NIC with hardware timestamping. We are humble to all the awesome products that are out there and we just wanted to present an open source version of a simplified approach to allow others to build on it.
I cannot find any source files for the FPGA code in the repository (no .v .vhd .vhdl files and I can't see anything by looking around manually). The FPGA directory [1] contains some binaries and some documents relating to commercial code from a Swiss firm [2]. I've seen plenty of projects described as open source when the firmware is open source and the hardware is closed but this is the first time I've seen one wher…
Man, tough crowd here. And someone who's been following precise timekeeping tech for 25 years now.. this is really cool! I think it's great some smart engineers have built a new reasonably compact and low cost very precise bit of timekeeping hardware. Thank you for sharing it open source!
I am torn. I absolutely love the technical blog post and the effort that went into open sourcing everything needed to build these devices, but, you know, Facebook. Compliments and respect to the engineers involved for really well done engineering.
I cannot find any source files for the FPGA code in the repository (no .v .vhd .vhdl files and I can't see anything by looking around manually). The FPGA directory [1] contains some binaries and some documents relating to commercial code from a Swiss firm [2]. I've seen plenty of projects described as open source when the firmware is open source and the hardware is closed but this is the first time I've seen one wher…
Earlier quoted context omitted.
Nice project, I've been working on something similar, but with an Arduino (Adafruit ESP32), an Adafruit GPS featherwing and a RTC. I originally started with a Linux-based solution like yours but no matter what I did I couldn't get the accuracy below about 5ms and my goal is sub-ms (verified with an oscilloscope.)
Yeah, I think you're on the right track. I like less and less having a Linux box to maintain, and there is less control over the timing of internal operations compared to a microcontroller, of course. On the other hand, Chrony is really, really good, and it would be a lot of code and debugging to write something that good from scratch. With the Beaglebone, it's theoretically possible to drive the oscillator from a ca…
I agree that I wouldn't likely notice a ~20ms jitter on the display, but I'm kinda of having fun figuring out how to make it as accurate as possible.