Smart PCB Diagnostic and Quality Inspection System for Electronic Manufacturing

This paper describes a low-cost automated connectivity tester for printed circuit boards (PCBs) built around an Arduino Nano (ATmega328P). Eight probe points, arranged as two groups of four, are connected directly to microcontroller pins. A drive-and-sense algorithm drives one probe LOW at a time and reads the remaining probes through the internal pull-up resistors, producing an 8 × 8 connectivity matrix that is compared with the expected pattern. Each difference is classified as an OPEN or a SHORT and reported by probe name on a 1.3-inch SH1106 OLED display, with PASS/FAIL LEDs and a transistor-driven buzzer. Because no multiplexers, op-amps or external pull-up resistors are used, the circuit was routed on a single copper layer of 83.5 × 54.9 mm with no vias. The schematic passed the electrical rules check with 0 errors, the layout passed the design rules check with 0 violations, and the firmware (7,918 bytes of flash, 813 bytes of RAM) was uploaded and verified byte for byte. Board-level testing revealed an intermittent contact between the Nano and its header socket, which was isolated systematically. Functional results on the assembled board are not reported because those tests have not yet been completed.