Schematic design and verification of the on-board computer for micro and nano satellites

Abstract

On-board Computer (OBC) is a very crucial component in any satellites. It is considered the brain that connecting and controlling subsystems. For each different space missions, requirements for OBC have various standards. There are so many inconveniences in the old structures of OBC when communicating with peripherals inside the systems. Protocols which had already been programmed nearly cannot be changed if adjustments are needed. Especially, when flexibility and convenience are considered foremost for small satellites. To tackle the problem, a detailed system structure must be created, as well as verification procedure. Within the thesis, a suitable schematic of OBC with FPGA was built, enabling the system to interface with ever protocols. Dealing with various mission, a selection of hardware – FPGA takes place. After completely building a suitable architecture for the system, verifying FPGA comes subsequently. Talking to external subsystems requires appropriate protocols such as SPI, I2C, CAN, UART, etc., but i only work with I2C and UART in this article. The experiment gives successful connection between FPGA and peripherals. A specific structure for the OBC with FPGA was made. The functions of it were evaluated on Xilinx Spartan-6 FPGA, using Verilog as coding language in ISE software. The results demonstrate the succeed access to the temperature module SHT10 and PL2302 module by sending and receiving data. All of this will consolidate the necessary of FPGAs for micro and nano satellite.