Forget Raspberry Pi: this computer is the literally the size of a credit card
A Reddit user spent months building a truly credit-card-sized computer — matching a payment card in thickness, not just length and width. Powered by an ESP32-C3 chip with Wi-Fi, Bluetooth, NFC, and an e-paper display, the fragile but functional prototype required hand-soldering wires onto 0.5mm pads and custom flex circuit boards.