In embodiments of human interface device (HID) over simple peripheral buses, a peripheral sensor receives inputs from a peripheral device, and the peripheral sensor implements an HID SPB interface to interface the peripheral device with a computing system via a simple peripheral bus (SPB) in an HID data format. The peripheral sensor can receive extensibility data for a proprietary function of the peripheral device, and communicate the inputs from the peripheral device and the extensibility data via the simple peripheral bus in the computing system. Alternatively or in addition, a peripheral sensor can generate sensor data and the HID SPB interface interfaces the peripheral sensor with the computing system via the simple peripheral bus. The peripheral sensor can then communicate the sensor data as well as extensibility data for a proprietary function of the peripheral sensor via the simple peripheral bus in the HID data format to the computing system.