Koppar LTE modem: a phone line over USB-C
Summary
Show HN coverage of Koppar-AI’s koppar-lte-modem, a USB-C LTE modem that presents a computer with a phone line (LTE data, SMS, and voice) via a USB hub and three on-board devices. The project is open hardware, with a KiCad design, BOM, and build instructions, showcasing an ultra-compact, open-source approach to adding cellular connectivity and telephony to a PC.