Cercedilla Field Notes: Hiking

What you see above are all the walks and hikes we have done in Cercedilla.

The gif was last updated 22/04/2026 and my objective is to paint the entire town and mountains orange!

When we first thought of getting cabin in the sierra mountains near Madrid, our first thought was of Cercedilla as we had some great hikes and experiences in the red pine forests around it, and as we have begun exploring it has not disappointed! Read on for more details and our discoveries!

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Pebble MoonSunTime Watchface

The above image is the drawings that I fed to Claude Code and the resulting working watchface for a Pebble Watch that was produced after 5 sessions (each one lasting until i burned through my tokens which was about 20 minutes a session).

People are bad talking “vibe coding”, but quite honestly “agentic coding” is so empowering! Read on for more details of the adventure!

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Cercedilla Field Notes: Linchen

Today, the first day of Spring of 2026, was unfortunately cloudy and raining all day, but fortunately this afternoon there was a pause in the rain and we were able to take a walk to the Ermita de San Antonio. Possibly due to the sky being grey and our attention not bound to the horizon, we noticed that all the rocks are cover in splotches of all sorts of different colors. My wife commented that it was because the rocks in the the Sierra around Madrid have a lot of granite (correct) and I said I thought that it was due to lichen (also correct). Read on for what I learned once we got home and I began investigating!

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Ersa Crash Postmortem

That was exciting! Yesterday morning I was having saturday morning coffee in bed doing a bit of prompt driven development to add weather predictions to my Remarkable sleep screen when suddenly weird things started happing on Ersa, a Raspberry Pi 4 Model B that hosts everything in my house including this blog. By weird I mean I was trying to create a new file but said it was a read only file system. I figured I had run out of space, but was not the case, so I opted for a “windows” solution: reboot. And that was all she wrote and Ersa did not come backup. The picture above is the open heart intervention on Ersa trying to figure out what was going on. Read on for the frantic recovery actions and a incident postmortem retrospective to ensure this learning experience leads to improvements!

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