Yesterday I decided to make a board that senses when a phone is sitting on top of it.

I was thinking along the lines of load cells and piezoelectric sensors, since I haven't used the latter before. However, I realized piezos don't measure a constant pressure. The voltage generated by a static pressure eventually fades to 0 as the charge dissipates. Good thing to know!
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A piezo would only detect me initially placing the phone down, but wouldn't know if it was still sitting there.

I started to consider load cells, but didn't want to relive the strain gauge nightmare. They're bulky and overkill too...

Wait, I can just think bigger.
My goal: Detect presence of a phone.
This does not mean I have to stick to measuring pressure!

When I place a phone down, not only does it exert pressure, but it also blocks the light underneath! Yesterday, I reminded myself of the existence of the humble photocell.

Useful Resources: https://www.pcb.com/resources/technical-information/introduction-to-force-sensors

I finally hauled my rework station back home! Forgot my retainer, though. Prioritization will be a recurring theme today.

In light of this quarantine, now's a good time to work on some side projects!

For one, I have trouble writing down all my ideas and prioritizing the project I want to do first.
A friend introduced me to Roam, a pretty nice note-taking tool, but I might just stick with pen and paper. It'll never lag.

We brainstormed and found it'd be neat to have a "Side Project Prioritization Tool" that assigned scores to potential project ideas based on:

• time to complete
• difficulty
• stuff I can learn from doing the project
• how much fun I'll have

...I figure it's a great way to procrastinate on a cool side project by building a different side project that prioritizes your side projects rather than directly working on your cool side project.

Coming soon: The Meta-Project-Project, another project that shouldn't exist. Let's see if it passes its own criteria...