🛰️ Instrument Simulator for REAL CubeSat (Flatsat)

Teensy 4.1–based simulator for the REAL CubeSat instrument, enabling robust spacecraft integration testing without needing physical flight hardware.

Project Purpose

This project implements an instrument simulator that emulates the behavior and data flow of the REAL CubeSat instrument.
Running on a Teensy 4.1 microcontroller, it supports full packet-level communication with the satellite’s On-Board Computer (OBC) over UART, following CCSDS telemetry standards.

The simulator:

• Receives command frames from the OBC
• Validates integrity with a CRC-CCITT16 checksum
• Responds with CCSDS-compliant telemetry frames
• Emits periodic “1 PPS” status updates
• Allows system debugging and validation without needing the flight instrument hardware

System Overview

• Platform: Teensy 4.1 (C++ / Arduino Core)
• Communication: UART (Serial2)
• Protocol: CCSDS Packet Standard
• Error Checking: CRC-CCITT16
• Design Goal: Mirror instrument state logic and communication timing of the actual payload

Core Features

Feature	Description
Command Interface	Parses and executes CCSDS command packets from the OBC
Telemetry Simulation	Generates housekeeping & science packets
CRC Validation	Implements 16-bit CCITT CRC with lookup optimization
Heartbeat System	Periodic “1 PPS” telemetry update and internal timekeeping
State Machine Architecture	FSM-based packet reception and handling (getData() loop)

Acknowledgements

• Developed at the Space Science Engineering Lab at Montana State University.

• Authors:
  Tyler Holliday, Connor Parrott, Andrew Johnson, Emma Stensland, Nevin Leh