Summary

This is the second part, the train receiver electronics and battery mount.
It holds and hides everything needed to control a model train.
This is controlled by another ESP (or something else).
It is designed to hold:
ESP32
-PAM8403 audio amplifier
-1 watt speaker
-5V, 1A Step-Up/Step-Down Voltage Regulator S13V10F5
-L298N Motor Drive Controller Board Module, Dual H Bridge (had to disable the onboard voltage regulator that was limited to 12v and use the external one above.)
-14.4V 2000mAh battery pack with BMS

More information at: https://coolate.com/blog/blog/2023/06/15/battery-powered-ladybug-eggliner-train-and-controller/

Also see part 1, the controller: https://www.thingiverse.com/thing:6080022