[thomas_OpenScan]

Actually, this is how I started the project. See for instance this one here (OpenScan in 2019 https://www.instagram.com/p/Bt6JtjEoEM7/)

But I have found that smartphones give very inconsistent results (probably due to image"improving" algorithms...), see https://www.instagram.com/p/B1q1syMoHfG/

So I moved on to the raspberry pi + camera, which is much easier and better to control as you need very, very consistent images...

[Causality1]

Interesting. What's the materials cost for the pi-based setup?

[thomas_OpenScan]

100-200€ plus the printed parts (~50€). But most people diy some or even all parts for even less