This is my DIY steam loco water filler that can move automatically through reed sensor trigering.The loco must have neodymium magnet attached underneath it in order the water filler can sense steam loco's presence.It also has arduino nano controller board with mini MP3 player to store the sound effect.

Buying this model also makes you eligible to get the manual instruction , the controller electronic diagram and the arduino sketch to make everything works. However due to too many kind of mini mp3 player copy out there I can not guarantee that the sound would work. Because certain mp3 player only works /understand certain sketch command. But that's not affecting the overall water filler performance. It can still move automatically even the sound doesn't works.

It is good if you have basic knowledge of arduino sketch so you can tweak some of the sound_related_part of the code if your mp3 doesn't work due to lack of compatibility.