INA226 Unit

This is the driver library of INA226 Unit, which is used to obtain current and power data from the INA226 sensor.

Support the following products:

UiFlow2 Example

get value

Open the ina226_core2_example.m5f2 project in UiFlow2.

This example gets the current, voltage, and power values from the INA226 Unit and displays them on the screen.

UiFlow2 Code Block:

Example output:

None

MicroPython Example

get value

This example gets the current, voltage, and power values from the INA226 Unit and displays them on the screen.

MicroPython Code Block:

# SPDX-FileCopyrightText: 2025 M5Stack Technology CO LTD
#
# SPDX-License-Identifier: MIT

import os, sys, io
import M5
from M5 import *
import m5ui
import lvgl as lv
from hardware import I2C
from hardware import Pin
import time
from unit import INA226Unit


page0 = None
label0 = None
label1 = None
label2 = None
label3 = None
i2c0 = None
ina226_0 = None


def setup():
    global page0, label0, label1, label2, label3, i2c0, ina226_0

    M5.begin()
    Widgets.setRotation(1)
    m5ui.init()
    page0 = m5ui.M5Page(bg_c=0xFFFFFF)
    label0 = m5ui.M5Label(
        "Bus Voltage:",
        x=0,
        y=56,
        text_c=0x000000,
        bg_c=0xFFFFFF,
        bg_opa=0,
        font=lv.font_montserrat_16,
        parent=page0,
    )
    label1 = m5ui.M5Label(
        "Current:",
        x=0,
        y=88,
        text_c=0x000000,
        bg_c=0xFFFFFF,
        bg_opa=0,
        font=lv.font_montserrat_16,
        parent=page0,
    )
    label2 = m5ui.M5Label(
        "Power:",
        x=0,
        y=124,
        text_c=0x000000,
        bg_c=0xFFFFFF,
        bg_opa=0,
        font=lv.font_montserrat_16,
        parent=page0,
    )
    label3 = m5ui.M5Label(
        "Shunt Voltage:",
        x=0,
        y=161,
        text_c=0x000000,
        bg_c=0xFFFFFF,
        bg_opa=0,
        font=lv.font_montserrat_16,
        parent=page0,
    )

    i2c0 = I2C(0, scl=Pin(33), sda=Pin(32), freq=100000)
    ina226_0 = INA226Unit(i2c0, 0x41, type="1A")
    page0.screen_load()


def loop():
    global page0, label0, label1, label2, label3, i2c0, ina226_0
    M5.update()
    time.sleep_ms(500)
    label0.set_text(
        str((str("Bus Voltage:") + str((str((ina226_0.read_bus_voltage())) + str("V")))))
    )
    label1.set_text(str((str("Current:") + str((str((ina226_0.read_current())) + str("A"))))))
    label2.set_text(str((str("Power:") + str((str((ina226_0.read_power())) + str("W"))))))
    label3.set_text(
        str((str("Shunt Voltage:") + str((str((ina226_0.read_shunt_voltage())) + str("V")))))
    )


if __name__ == "__main__":
    try:
        setup()
        while True:
            loop()
    except (Exception, KeyboardInterrupt) as e:
        try:
            m5ui.deinit()
            from utility import print_error_msg

            print_error_msg(e)
        except ImportError:
            print("please update to latest firmware")

Example output:

None

API

INA226Unit

class unit.ina226.INA226Unit(i2c, address=65, type='10A')

Bases: INA226

Create an INA226Unit object.

Parameters:

i2c (I2C) – The I2C bus the Accel Unit is connected to.
address (int) – The I2C address of the device. Default is 0x41.
type (str) – The type of INA226. Default is “10A”. Options are “1A” and “10A”.

UiFlow2 Code Block:

MicroPython Code Block:

from hardware import I2C
from unit import INA226Unit

i2c0 = I2C(0, scl=Pin(1), sda=Pin(2), freq=100000)
ina226_0 = INA226Unit(i2c0, address=0x41, type="10A")

INA226

class driver.ina226.INA226(i2c, addr=64, shunt_resistor=0.02)

Bases: object

Create an INA226 object.

Parameters:

i2c (I2C) – The I2C bus the INA226 is connected to.
address (int) – The I2C address of the device.
shunt_resistor (float) – The value of the shunt resistor in ohms. Default is 0.2.

UiFlow2 Code Block:

MicroPython Code Block:

from hardware import I2C
from driver import INA226

i2c0 = I2C(0, scl=Pin(1), sda=Pin(2), freq=100000)
ina226 = INA226(i2c0, 0x40, shunt_resistor=0.02)

calibrate(max_expected_current=0, cal_value=None)

Calibrate the INA226.

Parameters:

max_expected_current (float) – The maximum expected current in Amperes.
cal_value (int) – The calibration value to use. If None, it will be calculated based on the maximum expected current and the shunt resistor value.

MicroPython Code Block:

ina226_0.calibrate(10)

ina226_0.calibrate(cal_value=0xC80)

read_shunt_voltage()

Read the shunt voltage in Volts.

Returns:: The shunt voltage in Volts.
Return type:: float

UiFlow2 Code Block:

MicroPython Code Block:

ina226_0.read_shunt_voltage()

read_bus_voltage()

Read the bus voltage in Volts.

Returns:: The bus voltage in Volts.
Return type:: float

UiFlow2 Code Block:

MicroPython Code Block:

ina226_0.read_bus_voltage()

read_current()

Read the current in Amperes.

Returns:: The current in Amperes.
Return type:: float

UiFlow2 Code Block:

MicroPython Code Block:

ina226_0.read_current()

read_power()

Read the power in Watts.

Returns:: The power in Watts.
Return type:: float

UiFlow2 Code Block:

MicroPython Code Block:

ina226_0.read_power()