Taking my Pico clock from microseconds to nanoseconds

Check out my time-pi project for full details: https://github.com/geerlingguy/time-pi And the previous video on this mini rack 1U Pico GPS clock project: https://www.youtube.com/watch?v=E5qA4fgdS28 Support me on Patreon: https://www.patreon.com/geerlingguy Sponsor me on GitHub: https://github.com/sponsors/geerlingguy Merch: https://www.redshirtjeff.com Main Channel: https://www.youtube.com/@JeffGeerling 2nd Channel: https://www.youtube.com/@GeerlingEngineering Contents: 00:00 - Upgrading the Pico GPS clock 00:26 - PPS via LED 02:15 - PPS bodge to GPIO 16 03:16 - LCD's too bright 04:09 - UV tint and plastic tape filter 06:01 - 3D printing an integrated filter 07:45 - Any other ideas?