Abstract: Embodiments of devices, systems, and methods are disclosed that may be used to determine moisture content or chemical composition of a selected medium, such as soil. In an embodiment, a sensor device may include a first transducer configured to send data at a first time to a second transducer through a selected medium and to receive data at a second time from the second transducer through the selected medium. The sensor device may further include a controller coupled to the first transducer and configured to determine a propagation delay through the selected medium based on a difference between the first time and the second time and based on a pre-determined delay time. In some embodiments, the controller may control the first transducer to transmit in different frequencies and may determine the chemical composition based on the propagation delay at the different frequencies.