• Table of contents
• OsmoGTM900
  • Hardware
  • Firmware

OsmoGTM900¶

The OsmoGTM900 is an OSWH (Open Source Hardware) carrier board for the TI_Calypso_Chipset based Huawei GTM900-B GSM modem module. It contains

• power supply circuitry
• Analog audio connector
• SIM slot (2FF sized)
• reset and power-down buttons
• A Raspberry Pi Pico implementing a dual-USB-UART bridge as well as additional control
• (optional) audio codec intended to be used to interface the modem via USB-Audio Class device (requires firmware modification in the Pico firmware).

Hardware¶

The schematics in EAGLE format can be found at https://gitea.osmocom.org/electronics/osmo-small-hardware/src/branch/master/gtm900-breakout

A PDF rendering is available from https://gitea.osmocom.org/electronics/osmo-small-hardware/src/branch/master/gtm900-breakout/GTM900-breakout-schema_v3.pdf

Firmware¶

The firmware source code project for the Pico can be found at https://gitea.osmocom.org/laforge/rp2040-playground/src/branch/master/osmo-gtm900

At this point we do not yet have automatic builds, but intend to publish them at the usual location for osmocom projects, beneath https://ftp.osmocom.org/binaries/