This project expands upon a previously developed reconfigurable test fixture designed to test 7400 series digital integrated circuits used in printed circuit board assemblies. The goal is to provide a reliable test fixture that allows technicians to verify the functionality of integrated circuits in inventory and assist in diagnosing boards that fail acceptance testing. However, what if the fixture hardware malfunctions and the user is unaware? Without a method for the fixture to verify its own operational health, hardware failures can go unnoticed and produce unreliable test results. To solve this problem, multiple onboard self-tests were implemented targeting four common failure modes, corrupted flash memory, damaged or failed power supply rails, off-nominal clock/oscillator values, and missing or poorly soldered components. These self-test features include firmware integrity verification using a cyclic redundancy check, clock frequency validation, voltage rail monitoring using an analog to digital converter, power and ground configuration checks for the integrated circuits under test, and signal path, connection, and component verification using a loopback test. In combination with these self-test features, a dual seven segment display mechanism provides the user with a series of error codes should any of the self-test features fail, allowing the fixture to diagnose hardware faults without requiring a PC connection. The accompanying PC application interfaces with the test fixture over a serial connection and executes tests on specific 7400 series digital integrated circuits chosen by the user. The application allows users to control inputs, monitor outputs, and evaluate logic behavior based on truth tables. The system is designed to be easily extendable, enabling new integrated circuits to be supported through additional test scripts and or hardware additions.

Our team collaborated with Computer Science & Engineering 17 on this project.