What was done this week:
The focus of this week was about doing enough preliminary work to validate our design decisions. For me, that meant doing enough research to feel confident about a timing solution that would work on paper. I have extremely struggled with this goal. I feel like I do not have the technical expertise to understand many of the words I am reading.
Here is a summary of my research:
- We need <10 ns accuracy between anchors to have a semi-accurate localization
- There exist TDoA schemes that work without accurate time-sync but seemingly only in research papers and their accuracy results have been insufficient for our requirements
- I have found at least 2-3 other systems who claim their TDoA anchors use a 38.4MHz TCXO oscillator with a UWB receiver with time sync over UWB with syncs every 150ms
- Problem is, I don’t understand how any of this works. How does a clock at that slow speed ensure the precision of nanoseconds?
- Why doesn’t a RPi clock with GHz speed not give nanosecond accuracy with sync?
Frankly, much of this is confusing me and I think I need faculty help. Tamal told me that the RPi clock should theoretically suffice, so I have been trying to get a Rpi4 connected and write a time measuring sync.
The first RPi I got didn’t work and then setting up headless (without a display) took a while. I have not written time code but I have the RPi setup.
That will be the goal for the next week along with getting some help understanding TCXO setups for the next week.
I would say this part of the project is behind our original schedule. That said, the original schedule was mostly assuming the design was done. We want to have this finalized by design next week.