The Onboard Computer (OBC) is the central control unit of the CubeSat system, designed for low-power operation, robust interfacing, and modular telemetry/command handling. It serves as the core data and control hub, interfacing with sensors and subsystems over multiple buses including SPI, I2C, UART, and CAN.
This design emphasizes embedded systems learning, modular subsystem interaction, and reliable firmware development for space applications.
| Component Type | Component | Function |
|---|---|---|
| MCU Core | STM32L496ZGT6 | Main application processor |
| Clock | NX3225GA (16 MHz) | High-speed MCU clock |
| RTC | NX3215SA (32.768 kHz) | Real-time clock for timing and sleep mode |
| Watchdog | TPL5010Q1 | System reset if hung |
| Inertial | ISM330ISN | Accelerometer + Gyro |
| Magnetic | MMC5983MA | 3-axis magnetometer |
| MRAM | MR25H40MDF | Non-volatile fast memory |
| NOR Flash | S25HL512TFANHI010 | Bootloader/data storage |
| CAN Interface | TCAN332GDCNT | Satellite bus communication |
| UART Buffer | SN74LVC2G34DRLR | Signal integrity for UART |
| USB OTG | 473460001 | Micro USB port |
| Sun Sensor (x3) | 503763-0691 | SPI slave interface |
| GPS | 53261-0771 | Location services interface |
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STM32L496ZGT6
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Real-Time Clock & System Clocks
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Sensor Suite
ISM330ISN: IMU with embedded sensor hub and machine learning coreMMC5983MA: 3-axis high-precision magnetometer
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Watchdog Timer
- External watchdog for mission resilience and autonomous reset
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Memory & Storage
- MRAM (non-volatile, fast) for telemetry data
- NOR Flash for data logging and firmware storage
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Communication Interfaces
- CAN transceiver
- UART
- Micro-USB connector for OTG FS (for development/debug)
- Sun Sensor Connectors
- GPS Interface
- Powered via EPS board through PC104 connector
- Designed for low power consumption in deep-sleep modes
- All digital IOs are ESD-protected and power-aware
- Altium Designer – Schematic and PCB Layout
- STM32CubeIDE – Embedded development
- STM32CubeMX – Peripheral and clock config
- GitHub – VersVersion control , documentation and project showcase
Hitesh Bhoyar
Embedded Systems | CubeSat Design | Low Power Electronics
GitHub →
For educational use. Feel free to fork, reuse, or reach out if you are exploring embedded systems!
Visit the main repository for other subsystems.
Licensed under the MIT License