If defrost isn’t working, something in the chain is broken. This step-by-step approach shows you exactly where to look and what to test.

For around $25, the Neoteck TS20D is a fully-featured, well-made, and decently accurate tool that will handle most multimeter-related tasks. It's small enough to drop into a pocket or toolbox, durable ...

Ported from the RScada C library Libmbus, to C++ for use with Particle Photon and Electron. Maybe even the Core, but it will probably not work due to memory constraints.