A “Communication Device with Energy Efficient Sensing” provides various techniques for enabling a variety of sensor-based applications and processes while conserving energy on mobile communications devices. More specifically, the Communication Device with Energy Efficient Sensing provides a novel sensing architecture for mobile communications devices where sampling and, in various embodiments, processing, of sensor data received from one or more sensors is offloaded to a dedicated low-power processor having the capability to interact with a primary processor of the communications device. Such sensors include, but are not limited to accelerometers, ambient light sensors, compasses, microphones, pressure sensors, touch sensors, low-power radio devices, etc. This approach enables the communications device to perform continuous sensing with a low power overhead. In various tested embodiments, it has been observed that that the sensing architecture described herein can be two to three orders of magnitude more energy efficient in comparison to conventional communications devices.