This project started as a simple question: can a cheap phototransistor (L14G2) be “abused” into a sensitive, repeatable dust detector by measuring dynamic light scattering inside a purpose-built chamber? The answer: yes — with careful optics, laminar airflow, and a bit of signal processing the L14G2 becomes a low-cost particle counter / dust detector good enough for comparative studies and field testing. This page documents the build, the abuse (why it’s interesting), the benchmark plan (ZH03 today, BAM chamber upcoming), and the code/analysis approach so others can reproduce or improve it.