Hello, I'm considering options for my next project.
It should be able to run fully automated and will need block detection.
Now I'm considering to build a block detection module based on a ESP8266ex chip (Arduino+wifi on a chip), using groundloop and MQTT.
The module should be small enough to fit in the space underneath the C-rail. It will be powered from de DCC power, hence no extra wires are needed for block detection.
Design is almost done, now the challenge is to minimize all components while still being able to solder them.
The module should cost no more than 3-4EUR/$ each, so I'm very tempted to have one under each separate rail.

Now the question, has anyone attempted this already and may have pointers, gotchas or otherwise?
Thanks