Technical Guides

Why can building a second EEZ project into an existing generated directory remove files left by the first project?

What happens when two SerialRead activations try to consume the same Dashboard serial connection?

A fixture change does not automatically invalidate every earlier pass, but neither does a new successful station check validate all old results. Select earlier unit results by the measurement path, fixture/calibration revision and exposure interval that the change could affect. Hold records with insufficient scope evidence instead of treating missing metadata as proof that they…

After rework, verify the functions the repair could affect and attach the new evidence to the same unit’s unchanged failure history. Repeating only the original failed test can miss a disturbed connector, invalid calibration or a changed configuration introduced during repair. This article defines an original per-unit rework evidence method informed by NASA SP-2016-6105 Rev2….

Before applying a test stimulus through a switched fixture, establish both the commanded selection and the physical path that selection produced. Keep the route under one owner through stimulus and observation. A selector register reading back the requested channel does not prove that the intended contacts, wiring and load are connected. This is an original…

Count a power-cycle exposure only after evidence shows that the relevant device rails reached the required off state for the required interval. A relay command, a dark LED or a new console banner is insufficient by itself. Keep invalid exposures separate from functional failures after a valid cycle. This is an original campaign-validity procedure informed…

A two-device radio result belongs to a specific pair, direction and pair of software configurations. Bind both participants before starting and invalidate that association when either side reconnects or changes firmware. A good response from a nearby third device must not complete the intended pair’s test. This is an original paired-evidence procedure with one concrete…

A skipped or filtered test needs a reason before it can be removed from a coverage claim. Unsupported product hardware, missing bench equipment, unavailable host tools and deliberate selection filters are different conditions. Preserve them separately and reconcile every required configuration against actual execution evidence. The implementation examples below are pinned to Zephyr v4.0.0 Twister….

When tests fail only in parallel, first inventory shared names and mutable state. Two otherwise correct cases can overwrite one result file, change a process-global setting or reuse a cached connection. Adding a sleep may change the interleaving without repairing ownership. This guide focuses on runtime test-host interference, not shared electrical supplies or parallel build…

Compare old and new test parsers on identical raw fixtures, but judge both against an independently specified meaning. Agreement can preserve a shared defect. A justified parser change may deliberately alter a result, especially when the old implementation mishandled units, missing data or invalid numeric text. This article executes sixteen original host fixtures on CPython…