This session provides the practical skill of identifying UART pins on unknown devices. Because manufacturers rarely label these pins, students must apply systematic techniques to locate RX, TX, and GND. The instructor demonstrates using a multimeter to find ground, measuring idle voltages to spot transmit lines, and validating signals with oscilloscope or USB-to-UART converters. Common pitfalls, such as mistaking power lines for data pins, are discussed in detail to avoid hardware damage. This class connects to the module by ensuring students can reliably establish a physical UART connection, which is a prerequisite for all later exploitation techniques. Without proper pin identification, UART attacks cannot proceed.

Learning Objective
Learn reliable methods for identifying UART pins on target hardware.

Training Outcomes

• Trace and confirm ground lines.

• Differentiate between RX and TX pins.

• Interpret voltage levels (3.3V vs 5V).

• Validate UART communication safely.

Hands-On Experience

• Use a multimeter and oscilloscope to identify pins.

• Connect USB-to-UART converters for live testing.

• Validate UART output on unknown boards.