I hacked my sons Duplo train

[RedGreenBlack]

https://www.youtube.com/watch?v=t65X-cs55qM

[RedGreenBlack]

The speed can be controlled by the pitch of a persons voice. The higher the tone the quicker the train will go

If you would like to play around with it yourself then the code can be found here: https://github.com/benna100/duplo-train-voice-control

[eimrine]

Duplo means a hole on a tree in my language.