Current Sensor Module for Arduino & Raspberry Pi | ACS712

The Current Sensor Module for Arduino & Raspberry Pi | ACS712 uses the Hall effect to measure AC or DC current non-invasively. It provides an analog voltage output proportional to the measured current with 2.1kV isolation between sensor and measurement circuit.

Key Features

• Hall effect-based non-invasive current sensing
• Measures AC and DC current with bidirectional capability
• 2.1kV isolation between primary and secondary circuits
• Analog voltage output proportional to current
• Low internal resistance (1.2mΩ) for minimal power loss
• Available in multiple ranges (5A, 20A, 30A variants)
• 3.3V-5V operation with ratiometric output

Technical Specifications

Applications

• Current monitoring and power measurement
• Overcurrent protection systems
• Motor current sensing for stall detection
• Battery management and state-of-charge estimation
• Power factor measurement
• Electronic load monitoring

Important Notes

• Verify which variant you have (5A/20A/30A) – sensitivity differs
• 5A variant has highest resolution but lower maximum current
• Output is VCC/2 at zero current – measure this for calibration
• For AC measurement, sample rapidly and calculate RMS in software
• Place sensor in series with one conductor (not both in clamp-on style)