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Yet another DIY GPSDO - yes, another one

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AndrewBCN:
Hi,

A few weeks ago I set myself a challenge to develop a "better" project than FacePlant with twice the "performance" and at less than 1/10th the cost. So I am announcing the STM32 Open Time Server, a compact, inexpensive PTP/NTP server that can be plugged into any network and provide accurate timing.

This is basically a combination of the STM32 GPSDO with the UTC aligned 1PPS (which is still under development) and an STM32 development board with Ethernet. The interesting thing about the STM32 development board's onboard Ethernet interface is that it provides for IEEE-1588 hardware timestamping of Ethernet packets. The attached diagram makes clear the basic setup for this project.

I have a couple of STM32 development boards with Ethernet (STM NUCLEO-F429ZI) on their way courtesy of ST Micro, I'll post pictures when I get them.

Btw the code for the PTP server for the STM32 development board already exists, here: https://github.com/mpthompson/stm32_ptpd

bob91343:
I ran into my first stumbling block.  I was careful to purchase perfboard that has holes on 0.100" conters.  The OCXO has pin spacing of 0.75" so I am pondering drilling out a few holes so it will fit.

AndrewBCN:

--- Quote from: bob91343 on September 23, 2021, 01:03:16 am ---I ran into my first stumbling block.  I was careful to purchase perfboard that has holes on 0.100" conters.  The OCXO has pin spacing of 0.75" so I am pondering drilling out a few holes so it will fit.

--- End quote ---
Bob,
I recommend that you first assemble the STM32 GPSDO on a breadboard. But then again, suit yourself.
I wrote this three months ago:

--- Quote from: AndrewBCN on July 01, 2021, 08:54:35 pm ---...you need to solder longer leads to the 5 short leads of the OCXO, I suggest adding 5mm long leads.

--- End quote ---
See the attached picture. That takes 2 minutes and is the solution I found to use these OCXOs with a breadboard.

AndrewBCN:
The K150 PIC programmer just arrived! Now to check whether it survived shipping from China and try to program a couple of PIC12F675s with it.  :-/O

BTW if anybody is curious I found an open-source Python program that allows using the K150 under Linux, as explained here: https://eliasandrade.wordpress.com/2015/01/20/como-usar-o-gravador-pic-k150-no-linux/

Note the Python picpro.py program requires installing Python 2.7 which is deprecated in 2021. It doesn't work with Python 3.4 (I tested).

Edit 1: tested the K150 PIC programmer with picpro.py and it seems it managed to flash a picDIV correctly, but I'll only be able to test the picDIV tomorrow.
Edit 2: tested the picDIV running pd11.hex and it generates a 100┬Ás pulse @ 1Hz frequency, as designed. See attached DSO trace.

bob91343:
Okay I will solder leads to the OCXO and see how to secure the unit so as not to stress the solder.  I don't want to use my glue gun, as the unit runs warm enough that the glue is likely to soften.  So maybe a wire strap or epoxy or super glue or something else.

I removed the OCXO from the bit of PC board it was on.  I want to apologize for my incompetence here.  I used to be pretty good with this stuff but it's been a while and I don't have the visual acuity or steady hand I used to have.  I had my 89th birthday last month.

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