<p>Bioinspired in-sensor computing devices can process information at sensory terminals by leveraging physical principles, thereby reducing latency and energy consumption during computation while simultaneously enhancing the efficiency of data processing and real-time analysis. Optoelectronic devices exhibit in-sensor computing functions, such as feature enhancement and data compression, by tuning the defect states of the semiconductor channels and thereby modulating the photoresponsivity and time constants of the sensors. These functionalities are critically dependent on precise fabrication and testing protocols. Here we present a detailed procedure for fabricating and characterizing in-sensor computing devices based on nanoscale semiconductor thin films. We explain how to test such optoelectronic devices, including the testing of visual adaptation and motion perception responses. When using semiconductor materials obtained from commercial suppliers, this procedure is time efficient and results in highly reproducible device performance. Nevertheless, all device fabrication and testing steps are generalizable and can be extended to other semiconductor thin films grown using different methods. The procedure is intended for researchers experienced in cleanroom operations and microfabrication techniques and can be completed in ~14 d. The use of bioinspired optoelectronic devices enables the development of a framework for advancing in-sensor computing technologies.</p>