Hello Hacker News! I've spent the last 6 months or so designing and building this, The Attention Button. It's an IoT desk toy that lets you send a quick nudge to whoever you hold dear, letting them know you're thinking of them. Like a direct line to their attention. It is my first major electronics project and I have learnt so much making it. I'd love to hear what you guys think!
So, the website is essentially an HTTP interface for managing an MQTT broker. You create an account, make a "room" (application concept, not part of mqtt), and then put your account name and the room secret phrase into the device (it throws up a captive portal). The device then uses these to connect to the broker to an MQTT topic that's sha256(secret) and from there it's just simply passing messages between devices.
