Introduction¶

CircuitPython driver for the INA219 current sensor.

Dependencies¶

This driver depends on:

Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle.

Installing from PyPI¶

On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally from PyPI. To install for current user:

pip3 install adafruit-circuitpython-ina219

To install system-wide (this may be required in some cases):

sudo pip3 install adafruit-circuitpython-ina219

To install in a virtual environment in your current project:

mkdir project-name && cd project-name
python3 -m venv .env
source .env/bin/activate
pip3 install adafruit-circuitpython-ina219

Usage Example¶

see example

Contributing¶

Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.

Documentation¶

For information on building library documentation, please check out this guide.

Table of Contents¶

Simple test¶

Ensure your device works with this simple test.

examples/ina219_simpletest.py¶

"""Sample code and test for adafruit_ina219"""

import time
import board
from adafruit_ina219 import ADCResolution, BusVoltageRange, INA219


i2c_bus = board.I2C()

ina219 = INA219(i2c_bus)

print("ina219 test")

# display some of the advanced field (just to test)
print("Config register:")
print("  bus_voltage_range:    0x%1X" % ina219.bus_voltage_range)
print("  gain:                 0x%1X" % ina219.gain)
print("  bus_adc_resolution:   0x%1X" % ina219.bus_adc_resolution)
print("  shunt_adc_resolution: 0x%1X" % ina219.shunt_adc_resolution)
print("  mode:                 0x%1X" % ina219.mode)
print("")

# optional : change configuration to use 32 samples averaging for both bus voltage and shunt voltage
ina219.bus_adc_resolution = ADCResolution.ADCRES_12BIT_32S
ina219.shunt_adc_resolution = ADCResolution.ADCRES_12BIT_32S
# optional : change voltage range to 16V
ina219.bus_voltage_range = BusVoltageRange.RANGE_16V

# measure and display loop
while True:
    bus_voltage = ina219.bus_voltage  # voltage on V- (load side)
    shunt_voltage = ina219.shunt_voltage  # voltage between V+ and V- across the shunt
    current = ina219.current  # current in mA

    # INA219 measure bus voltage on the load side. So PSU voltage = bus_voltage + shunt_voltage
    print("PSU Voltage:   {:6.3f} V".format(bus_voltage + shunt_voltage))
    print("Shunt Voltage: {:9.6f} V".format(shunt_voltage))
    print("Load Voltage:  {:6.3f} V".format(bus_voltage))
    print("Current:       {:9.6f} A".format(current / 1000))
    print("")

    time.sleep(2)

`adafruit_ina219`¶

CircuitPython driver for the INA219 current sensor.

Author(s): Dean Miller

Implementation Notes¶

Hardware:

Software and Dependencies:

Adafruit CircuitPython firmware (2.2.0+) for the ESP8622 and M0-based boards: https://github.com/adafruit/circuitpython/releases
Adafruit’s Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice

class adafruit_ina219.ADCResolution[source]¶: Constants for bus_adc_resolution or shunt_adc_resolution

class adafruit_ina219.BusVoltageRange[source]¶: Constants for bus_voltage_range

class adafruit_ina219.Gain[source]¶: Constants for gain

class adafruit_ina219.INA219(i2c_bus, addr=64)[source]¶

Driver for the INA219 current sensor

bus_voltage¶: The bus voltage (between V- and GND) in Volts

calibration¶: Calibration register (cached value)

current¶: The current through the shunt resistor in milliamps.

power¶: The power through the load in Watt.

set_calibration_16V_400mA()[source]¶: Configures to INA219 to be able to measure up to 16V and 400mA of current. Counter overflow occurs at 1.6A.

Note

These calculations assume a 0.1 ohm shunt resistor is present

set_calibration_16V_5A()[source]¶: Configures to INA219 to be able to measure up to 16V and 5000mA of current. Counter overflow occurs at 8.0A.

Note

These calculations assume a 0.02 ohm shunt resistor is present

set_calibration_32V_1A()[source]¶: Configures to INA219 to be able to measure up to 32V and 1A of current. Counter overflow occurs at 1.3A.

Note

These calculations assume a 0.1 ohm shunt resistor is present

set_calibration_32V_2A()[source]¶

Configures to INA219 to be able to measure up to 32V and 2A of current. Counter overflow occurs at 3.2A.

..note :: These calculations assume a 0.1 shunt ohm resistor is present

shunt_voltage¶: The shunt voltage (between V+ and V-) in Volts (so +-.327V)

class adafruit_ina219.Mode[source]¶: Constants for mode