v2.2

Release of the AirGradient cellular extension (CE) card v2.2 — the plug-in 4G modem card for AirGradient air quality monitors (Open Air, ONE, and Open Air Max).

Built around the SIMCom A7671G modem (LTE Cat 1), plugging into the monitor's CE-card connector (CE1) and exposing the modem to the host over UART. 4-layer board.

Changes since v2.1

• GNSS support — GNSS enabled on the modem, with a dedicated U.FL antenna connector and 1V8 GNSS rail (10 µF added at the rail)
• USB-C logging interface added
• Analog switch upgraded from 2-channel to 4-channel (TS3A5018)
• Fitted cellular module is now the SIMCom A7671G (the design originally used the A7672G; archived Gerber filenames and the bundled 3D model keep the older naming)

Attached: ag-ce-A7671G-card.zip — the Gerber production set. BOM and pick-and-place CSVs are tracked in the repository under PCB/ag-ce-A7671G-card/production/.

Design files are in KiCad 10 format (2026-03).