Prototype Design of Estcube-2 Electrical Power System Control Electronics

Abstract

The aim of this thesis was to build a prototype of ESTCube-2 EPS subsystem control electronics. For that purpose, ESTCube-1 EPS was analyzed from the hardware perspective and all the areas where improvements could be made were listed. The requirements for ESTCube-2 EPS control electronics were set and a new design was implemented that improves the functionality and the reliability of the system while making it more robust. The testing results showed that the prototype meets or exceeds all the requirements that were set. The main results are following: • the supply voltage of the system is 3.3 V; • power consumption of 14 mW was achieved which is less than the requested maximum of 30 mW; • the prototype has 30 external ADC input channels which are measured within a time window of 70 μsec. The number of the ADCs can be incremented with no increase in the acquisition time; • the system includes voltage fault detection system that notifies the MCU about the voltage fault and holds the system operational for about 200 milliseconds. The hardware module that was built during the practical work has two separate microcontroller units - one for general tasks and other for diagnostics purpose. The prototype features 3.3 V voltage regulator for obtaining supply from the USB port, pin headers between the main supply and individual sections supply lines as well as in the inputs and outputs of all peripheral devices, debugging LEDs and test points for convenient debugging. The module can be easily connected to other EPS subsystem´s prototypes. The low level software that was written utilizes direct memory access that allows high speed data connection between two microcontrollers. The software is written in C language and enables to reuse the high level software of the ESTCube-1 thanks to similar function arguments and return types.