Payload

Camera Payload Subsystem

The Camera Payload represents the primary "mission" of the FlatSat satellite. It consists of a high-resolution imaging system designed to capture visual data of the "Earth" (or its surroundings) and transmit that data to the On-Board Computer (OBC) for processing and storage.

Technical Specifications

The payload is built to provide high-quality imagery while maintaining a low power profile suitable for small satellite operations:

Resolution: 5 Megapixels.
Image Format: Supports compressed JPEG output, which is ideal for reducing the data volume transmitted over satellite radio links.
Interface: Uses a combination of high-speed SPI for transferring large image data and I2C for camera configuration and control.
Control Logic: The payload is directly managed by the STM32F429ZI MCU on the OBC.

Hardware Connectivity

The Camera Payload is connected to the OBC via several dedicated pins to ensure high-speed data handling:

Interface	OBC Pin	Function
SPI CS	PE7	Chip Select for the Camera module.
SPI MOSI	PB15	Master Out Slave In for data transmission.
SPI MISO	PB14	Master In Slave Out for data reception.
SPI SCK	PB13	Serial Clock.
I2C SDA	PB9	Serial Data for camera configuration.
I2C SCL	PB8	Serial Clock for camera configuration.

Note: In some software implementations, SPI pins may be dynamically remapped to PB3, PB4, and PB5 to avoid conflicts with other SPI peripherals like the Flash memory.

Mission Operations

The typical operational flow for the camera payload involves the following steps:

Initialization: The OBC initializes the camera sensor via the SPI/I2C interface.
Capture: The OBC sends a "take picture" command.
Buffering: Image data is read from the camera's internal memory in small chunks (buffers).
Storage: The OBC writes these chunks sequentially to the Micro SD card (using the PC9/PC10/PC11/PC12 pins) to create a final .jpg image file.

Example Code

The following example code demonstrates how to trigger a picture capture and save the resulting file to the on-board SD card.

Feature	Description	Code Link
Camera to SD	Capture a 5MP image and save it as a JPEG file on the SD card.	obc_camera2sd.ino

PC104 Payload Expansion

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