ACS37800 Qwiic Power Meter

Built around the Allegro ACS37800, this Qwiic power meter lets your project monitor voltage and current at the same time over I2C. It is designed for higher-demand loads such as 3D printers, UAVs and solar panels, with voltage monitoring up to 60VDC and current sensing up to 30A.

The ACS37800 uses Hall-effect current sensing rather than a shunt resistor, helping avoid the heat generation and voltage drop associated with shunt-based designs. Its galvanic isolation keeps the logic-level sensing electronics separated from the high-current path.

For integration, the board connects neatly into the Qwiic ecosystem and exposes useful power data through its I2C interface. SparkFun also provides supporting documentation including a hookup guide, schematic, Eagle files, board dimensions, ACS37800 datasheet, Arduino library and hardware repository.

Features:

• Qwiic integration: Designed to slide seamlessly into your next Qwiic project.
• Simultaneous monitoring: Allows you to monitor voltage and current simultaneously without cutting traces or managing complex wiring.
• Hall-effect current sensing: Uses Hall-effect technology to measure current.
• Cool Operation: Because there is no shunt resistor, there is no heat generation or voltage drop, meaning the sensor itself doesn't waste the power it is trying to measure.
• Galvanic Isolation: The internal construction provides reinforced isolation between the current-carrying conductor and the sensing electronics, keeping your logic-level microcontroller safe from the high-current path.
• Complete Data: Reads Voltage, Current, and Power simultaneously.
• Onboard Intelligence: Features dedicated pins for zero-crossing detection and fast overcurrent fault reporting.
• Configurable: You can adjust settings like over/under-voltage thresholds directly via the Qwiic interface and save them to the chip’s onboard EEPROM.

Specifications:

• Voltage monitoring: up to 60VDC
• Current monitoring: up to 30A
• Power monitor IC: Allegro MicroSystems ACS37800
• Certification: UL 60950-1 (ed. 2) and UL 62368-1 (ed. 1) certified
• Isolation: Reinforced isolation up to 517 VRMS
• Primary conductor resistance: 0.85 mΩ primary conductor resistance for low power loss
• Ground compatibility: Compatible with floating and non-floating GND
• Bandwidth: 1 kHz bandwidth
• Current sensing range: up to +/- 30 A
• Default I2C address: 0x60
• I2C address configuration: I2C address can be changed and stored in EEPROM
• Voltage channel RMS noise: +/-0.3mV
• Current channel RMS noise: +/-0.1A
• Voltage channel total output error: +/-1% (-40°C to 125°C)
• Current channel total output error: +/-2% (25°C to 125°C)
• Current channel total output error: +/-2.7% (-40°C to 25°C)
• High current connections: Two 0.25” (6mm) through-holes for high current connections
• Current channel noise floor: approximately ±0.1A RMS

This board is best suited to heavier loads including motor control, battery charging, solar arrays and devices drawing less than 1 Amp. It is not intended for microcontrollers in sleep mode, single LEDs or applications requiring milliamp-level precision.