Reliability Envelope of a Buffered SBC Data Acquisition Platform for a Small-Engine Test Bench

Abstract

This paper develops a reliability model for a lowcost data acquisition platform built around a Raspberry Pi 4 and an MCP3008 converter. The available registration summary reports 1,304,600 stored rows over 51.88 s, corresponding to 25.15 krows/s and confirming operation at the target throughput scale. The scientific contribution is an analytical and reproducible Monte Carlo reliability envelope for the two-stage logger. The shared record buffer is represented as a finite discrete-time queue with Poisson arrivals, lognormal writer capacity, and one lognormal storage stall. Twenty-eight combinations of buffer capacity and mean stall duration were evaluated with 2,000 runs each using condition-specific deterministic streams derived from a fixed seed. At arrival and writer rates of 25 and 35 krecords/s, respectively, a 200,000-record buffer had overflow probabilities of 0, 0.0150, 0.7245, and 0.9980 for mean stalls of 4, 6, 8, and 10 s. Median retained fractions for 8 and 10 s were 0.9917 and 0.9584. The derived stability, stall-tolerance, and recovery relations provide quantitative design rules for buffer sizing, writer capacity, and diagnostic instrumentation.