Koppar LTE modem — USB-C phone line with EC25-EUX and RP2040 sound card
GitHub
85 x 65 mm, 4-layer KiCad 10 board that gives a computer LTE data, SMS and voice calls over one USB-C cable · An on-board USB hub exposes the EC25-EUX's network adapter and AT…
Insights: A worked example of integrating a cellular module: high-current power, 50 Ω-class RF feeds, SIM socket and a modem recovery mode · Shows how to bridge a modem's PCM audio to USB…
LTERP2040USB audio