[time-nuts] Can Anyone Help Me Get PPS Into This Mini PC?

[Ed Armstrong]

I recently purchased one of these mini PCs to be used as my router. 
https://cwwk.net/products/cwwk-x86-p5-super-mini-router-12th-gen-intel-n100-ddr5-4800mhz-firewall-pc-2x-i226-v-2-5g-lan-fanless-mini-pc?variant=44732374352104 



I am going to be running the new 64-bit Intel release of the excellent 
"Tomato" router firmwareTomato64 <https://tomato64.org/>, which can be 
installed either "bare-metal" or as a virtual machine. I am going the 
virtual machine route using proxmox v8.1.3. The tiny PC idles at about 9 
W and maxes out around 18 W, and has considerably more power than I need 
for my routing purposes. So, I also put my FreePBX on a separate virtual 
machine, also located on this mini PC. But that is probably not very 
interesting to anyone here, nor is it really part of my question.

Proxmox is a Linux based OS which is designed for the express purpose of 
running virtual machines. I suspect many of you on this mailing list may 
already be using it yourself. I am currently running my own stratum one 
NTP server on a Raspberry Pi 3 which is getting its PPS from a GPSDO. 
well, proxmox comes with chrony already installed, and I'm sure I could 
change it over to ntpd if I wished to do so. If any of you follow my 
first link, you will see the little mini PC has a header for GPIO. It is 
a 2x5 header with I believe a 2 mm pitch. According to the listing, 
there are four input and four output pins. I assume the other two pins 
are either both grounds or both positive, not really sure.

Now comes my question. Can any of you tell me how to use these GPIO 
pins? I can find tons of information very easily on setting this thing 
up as a router, NAS, or as a desktop computer. I have not been able to 
find a single post related to those GPIO pins. I can't find the pin out, 
can't find out what voltage they are supposed to work at, nor any 
information about communicating with them in Linux. I queried the 
system, hoping I could look up the motherboard online, and this is what 
I got:

root at Proxmox:~# dmidecode -t 2
# dmidecode 3.4
Getting SMBIOS data from sysfs.
SMBIOS 3.6.0 present.
# SMBIOS implementations newer than version 3.5.0 are not
# fully supported by this version of dmidecode.

Handle 0x0002, DMI type 2, 15 bytes
Base Board Information
 Â Â Â Â Â Â Â  Manufacturer: Default string
 Â Â Â Â Â Â Â  Product Name: Default string
 Â Â Â Â Â Â Â  Version: Default string
 Â Â Â Â Â Â Â  Serial Number: Default string
 Â Â Â Â Â Â Â  Asset Tag: Default string
 Â Â Â Â Â Â Â  Features:
 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  Board is a hosting board
 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  Board is replaceable
 Â Â Â Â Â Â Â  Location In Chassis: Default string
 Â Â Â Â Â Â Â  Chassis Handle: 0x0003
 Â Â Â Â Â Â Â  Type: Motherboard
 Â Â Â Â Â Â Â  Contained Object Handles: 0

root at Proxmox:~#

I also tried dmidecode -t baseboard, this obviously gave more details, 
but most devices were just listed as "other". I haven't found this to be 
terribly useful.

My desire is to replace the Raspberry Pi by syncing chrony or ntpd to 
the PPS in proxmox and using that instead. It would save a tiny amount 
of energy, and would remove the slight jitter caused by the ethernet 
port being on USP, I believe. Can anybody on here give me some idea on 
how to do this, or perhaps point me in the right direction to find the 
information I need.