In example implementations, an apparatus for detecting hardware components is provided. The apparatus includes a multipurpose integrated circuit comprising an input pin, a hardware component coupled to the input pin and a two-way communication bus coupled to the multipurpose integrated circuit. The multipurpose integrated circuit is to receive an interrogation signal from a processor for the hardware component coupled to the pin via the two-way communication bus. A response signal that indicates that the hardware component is detected on the pin is generated in response to the interrogation signal. The response signal is then transmitted to the processor over the two-way communication bus.