Sensor devices that monitor environmental changes in temperature, sound, light, vibration and pressure usually run applications that require the support of a small operating system, lean kernel, or an embedded system. This paper presents a methodology for developing sensor device applications that can be directly run on the bare hardware without any need for middleware. Such bare sensor device applications only depend on the underlying processor architecture, enabling them to run on a variety of devices. The methodology is used for developing, designing, and implementing a temperature sensor application that runs on an ARM processor. The same methodology can be used to build other bare machine sensor device applications for ARM processors, and is easily extended to different processor architectures.