What is a Current Sensor?
A current sensor detects and measures the electrical current flowing through a conductor or circuit. Depending on the sensor, current can be measured using a Hall effect sensor, a shunt resistor and current-sense amplifier, or non-invasive sensing. The resulting measurement can then be read by a microcontroller such as an Arduino, Raspberry Pi, or other embedded system.
Current sensing is commonly used for:
- Battery monitoring – Measure charging and discharging current and track energy consumption.
- Motor and robotics projects – Monitor motor current to identify changes in load, stalls, or unexpected power consumption.
- Power monitoring – Measure current, voltage, and power usage in embedded devices and electrical systems.
- Energy management – Track how much power a device or subsystem consumes over time.
- Circuit protection and diagnostics – Detect abnormal current draw that could indicate a fault or overloaded circuit.
- IoT and data logging – Record current and power measurements for remote monitoring, testing, and analysis.
Choosing a Current Sensor
The right current sensor depends on the type of current you need to measure, the expected current range, required accuracy, electrical isolation, and how you want to communicate with the sensor.
Hall effect current sensors can measure current while providing electrical isolation between the monitored circuit and your measurement electronics. High-side current sensors use a small shunt resistance to accurately measure current flowing through a circuit. Coulomb counters measure accumulated charge over time, making them useful for battery-powered applications. Non-invasive current sensors can measure AC current without requiring a direct electrical connection to the conductor.
SparkFun also offers Qwiic current and power sensors that simplify integration with compatible development boards using I²C, making it easier to add current, voltage, and power monitoring to prototypes and embedded systems without extensive wiring.
Whether you're measuring the current draw of a motor, monitoring a battery, analyzing power consumption, or building an energy-monitoring system, SparkFun current sensors provide flexible options for adding real-time electrical measurements to your project.