05 Data Acquisition in Embedded Systems

A set of vocabulary flashcards covering fundamental terms and concepts from the lecture on data acquisition systems in embedded applications.

Data Acquisition (DAQ)

The process of measuring electrical or physical phenomena and converting the resulting signals into digital data a computer can process.

Data Acquisition System (DAS)

An integrated setup consisting of sensors, signal-conditioning hardware, a computer or microcontroller, and software used to acquire, store, visualize, and process data.

Sensor

A device that converts a physical phenomenon—such as temperature, pressure, or light—into a measurable electrical signal.

Analog Signal

A continuous-time signal that can take any value within its range with respect to time.

Digital Signal

A discrete-time signal that assumes only two states, commonly referred to as logic HIGH and logic LOW.

Signal Level

The instantaneous amplitude of an analog signal at a specific moment in time.

Signal Shape (Waveform)

The overall form of an analog signal, revealing characteristics such as peaks, slopes, and area under the curve.

Signal Frequency

The number of occurrences of a periodic event per unit time in an analog signal, often determined by mathematical methods like FFT.

Signal Conditioning

Any technique—internal or external to a DAQ device—that converts a raw sensor signal into a form suitable for accurate digitization.

Amplification

Signal-conditioning method that increases a sensor signal’s amplitude to maximize ADC resolution and improve signal-to-noise ratio.

Attenuation

Signal-conditioning method that reduces a signal’s amplitude to keep it within the safe input range of the ADC or DAQ device.

Filtering

The removal of unwanted noise or frequency components from a signal, such as with a low-pass filter that blocks high-frequency noise.

Isolation

The technique of transferring a signal to measurement circuitry without direct electrical connection, preventing ground loops and high common-mode voltages.

Analog-to-Digital Converter (ADC)

The component in a DAQ system that transforms conditioned analog signals into streams of digital data.

Resolution

The smallest change in input voltage an ADC can detect, determined by the number of binary quantization levels (bits).

Input Range (Measurement Range)

The minimum-to-maximum span of signal values a DAQ system can measure accurately without saturation or damage.

Sampling Rate

The frequency at which an analog signal is measured by a DAQ system during conversion to digital form.

Aliasing

Distortion that occurs when a signal is sampled below twice its highest frequency component, causing high-frequency content to masquerade as lower frequencies.

Nyquist Theorem

Principle stating that perfect reconstruction of a signal requires a sampling rate at least twice the signal’s highest frequency component.