// Project case study
Summit Signal — Iridium IoT SOS Device
Handheld satellite SOS beacon with 100% global coverage — no cell network required.
Summit Signal is a handheld satellite communicator built for explorers who go beyond cellular coverage. It relays live location, heading, and SOS messages from anywhere on Earth over the Iridium satellite network, pairing a custom-designed PCB with cloud connectivity through AWS.
- Year
- 2024
- Role
- Sole designer — hardware, firmware, and system architecture
- Context
- Personal project · M.S. capstone
- Tech stack
- Altium DesignerTeensy 4.1C++Iridium SBDGNSSLi-Ion Power PathI2C / UART
- 100%
- global coverage via Iridium
- 2
- seamless power sources
- AWS
- cloud-connected telemetry
Embedded architecture
A Teensy 4.1 microcontroller runs custom C++ firmware that orchestrates the RockBLOCK 9603 Iridium transceiver for short-burst-data uplinks with true pole-to-pole coverage, a SAM-M10Q GNSS module with integrated patch antenna for live positioning, and an IMU for motion and heading data. Telemetry — location, heading, speed — is continuously logged to a micro SD card for post-trip analysis, with I2C and UART buses tying the sensor suite together.
Power architecture
A priority power multiplexer switches seamlessly between a 3.7V Li-Ion battery and 5V USB input, with an onboard charger IC topping up the battery whenever USB is present. A 5V boost and 3.3V buck regulator serve every rail on the board. Gate-driver ICs level-shift the MCU's 3.3V GPIO to 12V to drive the FETs behind the high-visibility status LEDs.
Design goals
Robust satellite connectivity, a compact handheld form factor, and battery life measured in days — achieved through aggressive power budgeting and duty-cycled radios. The full design was captured and laid out in Altium Designer.