Project Strix is the avionics system for Martlet IV. Originally conceived as a direct successor to the Martlet III avionics system, issues stemming from the 2020-21 silicon shortage and backported features from Project Rooster resulted in a completely novel system architecture, and fancy new name.
The system is designed as a single-board flight computer, composed of a single microcontroller linked to several independent subsystems. Each of these systems is explored in detail below, but the key components are:
- The power supply and battery charger
- A dual-output clock distribution system
- A redundant altimeter
- The telemetry radio and GPS system
- Recovery pyrotechnics fire control
- An engine sensor datalogging interface
- Two serial interfaces
- The Central Processor
The boad is controlled by a single STM32F405RGT6 microcontroller. This chip, powered by a 32-bit ARM Cortex-M4, runs the core state machine in addition to several functions pertaining to each subsystem, including altitude estimation, data sampling and logging, telemetry and telecommand handlingm and PSU and Battery Management.