The X-NUCLEO-OUT08A1 industrial digital output expansion board for STM32 Nucleo provides a powerful and flexible evaluation and development environment for 2 A (typ.) digital output modules, featuring the safe driving and smart diagnostic capabilities of the IPS160HF single high-side switch. The X-NUCLEO-OUT08A1 interfaces with the microcontroller on the STM32 Nucleo via 3 kV optocouplers driven by GPIO pins and Arduino™ UNO R3 (default configuration) and ST morpho (optional, not mounted) connectors. The expansion board should be connected to either a NUCLEO-F401RE or NUCLEO-G431RB development board, and can also be stacked with another X-NUCLEO-OUT08A1 or X-NUCLEO-OUT10A1. Up to four X-NUCLEO-OUT08A1 expansion boards can be stacked to evaluate up to a quad channel digital output module with 2 A (typ.) capability each. It is also possible to evaluate the typical cascade architecture of a single channel digital output module for safety applications: in this scenario, the first shield output is connected to the supply of the second one. Dedicated on-board hardware can be enabled or disabled to activate fast discharge of high capacitive loads, output voltage sensing, and an additional surge pulse output line protection.