SPIDER Automation Adafruit INA219 FeatherWing Power Monitor | INA219B High-Side Current & Voltage Sensor | For Feather-Based Power Monitoring
Description
The Adafruit INA219 FeatherWing Power Monitor is a compact power-monitoring expansion board designed around the INA219B current and voltage monitoring IC. It enables compatible Feather boards to measure both high-side DC current and bus voltage through an I2C interface, providing useful electrical measurements without requiring separate external meters for basic embedded monitoring applications.
Unlike low-side current measurement, high-side sensing places the measurement element in the positive supply path, helping preserve the target circuit’s ground reference. The board uses a 0.1Ω, 1% current-sense resistor and a precision amplifier to measure the voltage developed across the resistor. With the amplifier’s maximum differential input of ±320mV, the standard resistor provides an approximate measurement range of ±3.2A.
The INA219B incorporates a 12-bit ADC and programmable gain. At the maximum ±3.2A range, the stated current resolution is approximately 0.8mA. With the internal gain configured to div-8, the measurement range can be reduced to approximately ±400mA with approximately 0.1mA resolution. Advanced users can replace the standard sense resistor with another value to adapt the board for a different current-measurement range.
The board communicates through I2C and supports configurable addressing, allowing up to four INA219 boards to operate on the same I2C bus when different addresses are selected. This makes the FeatherWing suitable for monitoring multiple power rails, batteries, solar panels and other DC-powered systems.
Key Features
- INA219B Chipset: Integrates high-side current and bus-voltage monitoring functionality.
- High-Side Current Sensing: Measures current in the positive supply path without requiring the load ground to be lifted.
- Bus Voltage Measurement: Monitors high-side voltage up to 26V DC.
- 0.1Ω Sense Resistor: Includes a 0.1Ω current-sense resistor for standard current measurement.
- 1% Sense Resistor: The supplied current-sense resistor has a stated 1% tolerance.
- ±320mV Differential Range: The precision amplifier supports a maximum input difference of ±320mV.
- ±3.2A Standard Range: The 0.1Ω sense resistor enables approximately ±3.2A maximum measurement range.
- 12-Bit ADC: Provides high-resolution digital conversion for voltage and current measurements.
- 0.8mA Resolution: Approximate current resolution at the ±3.2A measurement range.
- ±400mA Lower Range: With minimum div-8 gain, the current range can be reduced to approximately ±400mA.
- 0.1mA Resolution: Approximate current resolution available in the ±400mA range.
- I2C Communication: Provides a simple digital interface for compatible Feather controllers.
- Configurable I2C Address: Allows multiple INA219 boards to share a single I2C bus.
- Up to Four Devices: Up to four INA219 boards can be configured with different I2C addresses.
- 3.3V Operation: Board logic and voltage regulation are designed around 3.3V Feather operation.
- Replaceable Sense Resistor: The standard resistor can be replaced to customize the current-measurement range.
Benefits
- Accurate Power Monitoring: Provides digital current and voltage measurements through the INA219B monitoring architecture.
- Ground Reference Preservation: High-side sensing avoids placing the measurement resistor in the load’s ground path.
- Direct Feather Integration: Provides a compact expansion-board format for compatible Feather systems.
- Multi-Rail Monitoring: Multiple boards can be used on the same I2C bus with separate addresses.
- Customizable Current Range: Replacing the sense resistor allows the measurement range to be adapted for specialized applications.
- Low Hardware Complexity: Integrates current sensing, voltage measurement and ADC functionality into a compact monitoring solution.
Applications
- Battery Monitoring: Measuring battery bus voltage and DC current consumption in embedded systems.
- Solar Power Monitoring: Monitoring voltage and current in low-voltage solar-powered systems.
- Embedded Power Measurement: Adding digital current and voltage measurement to Feather-based controllers.
- Power Consumption Analysis: Tracking DC current draw of electronic equipment and embedded loads.
- IoT Systems: Monitoring electrical parameters in connected sensor and control equipment.
- Portable Electronics: Measuring battery-powered system consumption and supply voltage.
- Multiple Power-Rail Monitoring: Using multiple boards on a shared I2C bus for separate supply measurements.
- Electronic Prototyping: Adding programmable power measurement to Feather-based development systems.
Package Includes
- 1 × Adafruit INA219 FeatherWing Power Monitor
Technical Specifications
| Parameter | Specification |
|---|---|
| Product Type | Development Board / FeatherWing Power Monitor |
| Board Type | Feather Type |
| Manufacturer | Adafruit Industries |
| Monitoring IC | INA219B |
| Measurement Type | High-Side DC Current and Bus Voltage |
| Communication Interface | I2C |
| Maximum Bus Voltage | 26V DC |
| Current Sense Resistor | 0.1Ω, 1% |
| Maximum Amplifier Differential Input | ±320mV |
| Standard Current Measurement Range | Approximately ±3.2A |
| Lower Current Measurement Range | Approximately ±400mA at div-8 gain |
| ADC Resolution | 12-Bit |
| Current Resolution at ±3.2A | Approximately 0.8mA |
| Current Resolution at ±400mA |