Show HN: A USB-C LTE modem that gives my computer a phone line

Category: infrastructure

Tags: lte, usb, open-hardware, kicad, rp2040, telephony

Score: 6.8/10 (Innovation: 6, Technical: 8, Documentation: 8, Utility: 5)

A fully open-source 4-layer KiCad hardware design for a USB-C LTE modem that exposes data, SMS, and voice calls (with PCM audio via an RP2040 USB sound card) to a host computer. The project includes schematic, fabrication files, BOM, design review, and firmware, making it a practical reference for building a voice-capable LTE dongle. It is notable for being a complete, manufacturable open-hardware design rather than just a schematic or breakout.

Target audience: hardware engineers, embedded developers, telecom/voip hobbyists

Repository: https://github.com/Koppar-AI/koppar-lte-modem · CERN-OHL-P-2.0 · 18 stars

View on Hacker News