On-Orbit Implementation of Discrete Isolation Schemes for Improved Reliability of Serial Communication Buses

Serial communication buses are used in electronic systems to interconnect sensors and other devices, but two of the most widely protocols, i.e., interintegrated circuit (I2C) serial peripheral interface (SPI), vulnerable bus-wide failure if even one device on bus malfunctions. For aerospace applications demanding increasingly more distributed processing sensing capability, compounding risk system reliability as count scales becomes a limiting factor mission scope, performance, lifetime. We propose simple external be added each node that automatically isolates event failure. By isolating failed integrity is preserved without requiring additional signals or overhead from host controller. In this article, I2C SPI isolation circuits simulated, fabricated, experimentally verified effective at preserving The were integrated into three spacecraft for successful NASA V-R3x found significantly improve by eliminating single-point modes buses. developed protection schemes valuable tool decoupling can readily existing systems.