Abstract: To collect data, an electronic device transmits a signal on an output channel of the headset jack to provide an excitation signal to a sensor for measuring a physical quantity. A signal from the sensor is received via an input channel of the headset jack of the electronic device. Data based on the received signal may be sent from the electronic device to a remote location for further processing. The data may be used to detect a physical condition, e.g., a temperature, humidity, soil moisture, sound, vibration, pressure, motion, and/or pollutants.

Abstract: To analyze a sample, an image comprising a calibration chart region and a representation of the sample is accessed. The calibration chart region has multiple reference markers. The reflectance value for each of the reference markers is determined. In one example, the reflectance value may be reflectance values in the red wavelength. Each of the reflectance values is associated with a quantity value corresponding to the reference markers. An exponential function relating the reflectance values and the associated quantity values is determined. The reflectance value for the representation of the sample is determined. In one example, the reflectance value for the sample may be the reflectance value in the red wavelength. A quantity value of the sample is determined based on evaluating the exponential function using the sample reflectance value.

Abstract: To collect data, an electronic device transmits a signal on an output channel of the headset jack to provide an excitation signal to a sensor for measuring a physical quantity. A signal from the sensor is received via an input channel of the headset jack of the electronic device. Data based on the received signal may be sent from the electronic device to a remote location for further processing. The data may be used to detect a physical condition, e.g., a temperature, humidity, soil moisture, sound, vibration, pressure, motion, and/or pollutants.