Rb Time Standard
I have an odd obsession with time. It’s the one thing we can’t control, have a finite amount of, and can never gain back. It’s an expense. With that said, I wanted to build a better time standard within my house, and after doing some research, settled on Rubidium time sources. This is my build log of an Rb time source.
Core Components Needed
- RaspberryPi 3 with Raspbian
Let’s get it on
They can have a time accuracy of 2x10^-11
The ones we'll use are recycled from decomissioned cell towers
Part number: FE-5680A
Beware of the mutliple form factors that exist with the same part number.
NOTE: You'll look for a 1PPS and 10MHz output
For background, here is how a Rb oscillator works:
what you will be looking for specifically is this:
I won’t get into how these work here yet, but what you’ll need to figure out is how to get the 1PPS pin into the Raspi. I’m finishing a board to do all this for you as a shield. The main issue from just putting it together is that the 1PPS is a very short and powerful burst as seen below:
This needs to be expanded from 1us to 100ms, and reduced from 5VDC to 3.3VDC.
You can download the code for the raspi here