The Bowser Wallet, a cheap DIY hardware wallet on the M5Stack, hidden behind “Bowser Tettris Chaos!”
Building your own hardware wallet is a bit like building a lightsaber, only really necessary if you want to be a Jedi.
https://github.com/arcbtc/bowser-bitcoin-hardware-wallet

More BTCIOT Tutorial: Bowser, DIY Bitcoin Hardware Wallet Videos