How it works:
→ a QR code is displayed next to a model railway
→ scan it with any Lightning wallet
→ pay 100 sats (~$0.06)
→ relay on Raspberry Pi triggers instantly
→ steam locomotive starts rolling 🚂⚡

No cloud, no subscription, no 3rd party dependencies. Runs entirely on a Raspberry Pi with a custom relay card.

The goal is to make Bitcoin Lightning tangible for everyone — old and young. This is what machine payments look like.

📹 Video: https://twitter.com/cointrain33/status/2043729925295792555
🌐 satoshkey.com

Happy Choo Choo