An environmental monitoring device that monitors the operation of a legacy electronic device is described. In particular, a sensor in the environmental monitoring device provides sensor data that represents an environmental condition in an external environment that includes the environmental monitoring device. This environmental condition is associated with the operation of the legacy electronic device in the external environment. The environmental monitoring device analyzes the sensor data and provides feedback about the operation of the legacy electronic device based on the analyzed sensor data. Moreover, the sensor provides the sensor data without or excluding communication and/or electrical coupling between the environmental monitoring device and the legacy electronic device. In this way, the environmental monitoring device facilitates monitoring, analysis and feedback of the sensor data without directly interacting with the legacy electronic device.