System Architecture

Introduction

System Architecture Plan

There are three main parts of the system�s software architecture. The first being pre-flight waiting. The second being data acquisition and recording. The last being receiving requests from the CDH and sending data from the SD Flash Card memory of what was recorded.

Low power pre-flight standby waiting for Launch detection. Launch is detected when 10Gs of force is detected on one of the vertical accelerometers.

Data Acquisition Mode

After Mission command mode for downloading data to CDH for transmission to ground station.

Block diagram including simplified interfaces, i.e. SPI to flash SD Card, UART to CDH, analog from sensors.

Not shown is power to μProcessor and voltage reference of 5.0V for A/D interfaces.

System Interfaces

The figure below shows all enable and data signals that are part of the IMU Microprocessor interface to command and data handling subsystem on the spacecraft. All mechanical interfaces are out of the scope of this document and are described in the CubeSat IMU Design report.

Figure 1: N2 Matrix for the CubeSat IMU MIcroprocessor

Sub-System Interfaces

The CubeSat IMU Microprocessor will interface with a flash chip to store collected sensor data the ADC is on-board to the PIC24 chip and therefore not considered a subsystem interface.

User Interfaces

The CubeSat IMU Microprocessor has only interfaces to being able to recode it for operation; this is because it will operate in the dynamic environment of space so when in use it will not be able to be interfaced with, i.e. it will be completely autonomous.