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[讨论] Beetle 树莓派RP2350 - 便携INA219功率计

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Beetle 树莓派RP2350 - 便携INA219功率计

本文介绍了 DFRobot Beetle RP2350 开发板结合 INA219 模块实现功率计，并通过 LabVIEW 上位机串口采集 INA219 电流、电压数据的项目设计。

项目介绍

本项目包括 INA219（关键部件）芯片介绍、工作原理、参数特点等信息，在此基础上实现工程代码编写、硬件测试等流程，最终实现功率计制作。结合LabVIEW上位机，实现功率数据采集和曲线分析等。

INA219 模块

DFRobot Gravity：I2C数字功率计是一款可测量 26V, 8A 以内各类电子模块、用电设备的电压、电流和功率，最大相对误差不超过±0.2%的高分辨、高精度、大量程测量模块（首次使用需进行手动校准）。

可用于太阳能系统、电池库仑计、电机、主控板或电子模块的功耗测量、电池续航评估与实时电源参数在线监控。

模块采用 TI INA219 零温漂电流/功率监控芯片和 2W 大功率低温漂 10mΩ 合金采样电阻，

电压和电流分辨率分别可达 4mV 与 1mA，

在满量程测量条件下，电压与电流的最大测量相对误差不超过±0.2%，

并提供4个可通过拨码开关配置的I2C地址。

模块可对双向高侧电流（流经电源或电池正极的电流）进行准确测量，这在太阳能或库仑计应用，电池既需要充电，也需要放电的场合尤为有用，

用户可通过电流的正负读数了解电池的充放电状态，也可以了解电池的冲放电的实时电压、电流与功率。

在电机应用场景，可通过实时监控电机电流是否由于堵转或负载过大导致电流过大，从而及时采取保护措施。

此外，也可以使用该模块测量各类电子模块或整个项目的实时功耗，从而评估电池的续航时间。

特性

高精度、高分辨率、大量程、低温漂
双向电流高侧测量
兼容3.3V/5V控制器
精致小巧，方便项目嵌入

接口说明

[td]

名称	功能描述
VCC	电源正极（3.3~5.5V）
GND	电源负极
SCL	I2C时钟线
SDA	I2C数据线
ADDR	I2C地址选择拨码开关
3P TERMINAL	电压与电流测量接线柱3P

模块原理图

INA 原理图

总线时序图

IIC 通信起始地址为 0x40

详见：Gravity: I2C Digital Wattmeter SKU: SEN0291-DFRobot .

工程代码

通过复用 IIC 引脚 GPIO4 和 GPIO5 ，实现 INA219 模块的数据采集、终端打印以及 OLED 显示。

上传 ina219.py 至芯片根目录

# The MIT License (MIT)
#
# Copyright (c) 2017 Dean Miller for Adafruit Industries
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
"""
`adafruit_ina219`
====================================================

CircuitPython/MicroPython driver for the INA219 current sensor.

* Author(s): Dean Miller
"""

from micropython import const
# from adafruit_bus_device.i2c_device import I2CDevice

__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/robert-hh/INA219.git"

# Bits
# pylint: disable=bad-whitespace
_READ = const(0x01)

# Config Register (R/W)
_REG_CONFIG = const(0x00)
_CONFIG_RESET = const(0x8000)  # Reset Bit

_CONFIG_BVOLTAGERANGE_MASK = const(0x2000)  # Bus Voltage Range Mask
_CONFIG_BVOLTAGERANGE_16V = const(0x0000)  # 0-16V Range
_CONFIG_BVOLTAGERANGE_32V = const(0x2000)  # 0-32V Range

_CONFIG_GAIN_MASK = const(0x1800)     # Gain Mask
_CONFIG_GAIN_1_40MV = const(0x0000)   # Gain 1, 40mV Range
_CONFIG_GAIN_2_80MV = const(0x0800)   # Gain 2, 80mV Range
_CONFIG_GAIN_4_160MV = const(0x1000)  # Gain 4, 160mV Range
_CONFIG_GAIN_8_320MV = const(0x1800)  # Gain 8, 320mV Range

_CONFIG_BADCRES_MASK = const(0x0780)   # Bus ADC Resolution Mask
_CONFIG_BADCRES_9BIT = const(0x0080)   # 9-bit bus res = 0..511
_CONFIG_BADCRES_10BIT = const(0x0100)  # 10-bit bus res = 0..1023
_CONFIG_BADCRES_11BIT = const(0x0200)  # 11-bit bus res = 0..2047
_CONFIG_BADCRES_12BIT = const(0x0400)  # 12-bit bus res = 0..4097

_CONFIG_SADCRES_MASK = const(0x0078)              # Shunt ADC Res. &  Avg. Mask
_CONFIG_SADCRES_9BIT_1S_84US = const(0x0000)      # 1 x 9-bit shunt sample
_CONFIG_SADCRES_10BIT_1S_148US = const(0x0008)    # 1 x 10-bit shunt sample
_CONFIG_SADCRES_11BIT_1S_276US = const(0x0010)    # 1 x 11-bit shunt sample
_CONFIG_SADCRES_12BIT_1S_532US = const(0x0018)    # 1 x 12-bit shunt sample
_CONFIG_SADCRES_12BIT_2S_1060US = const(0x0048)   # 2 x 12-bit sample average
_CONFIG_SADCRES_12BIT_4S_2130US = const(0x0050)   # 4 x 12-bit sample average
_CONFIG_SADCRES_12BIT_8S_4260US = const(0x0058)   # 8 x 12-bit sample average
_CONFIG_SADCRES_12BIT_16S_8510US = const(0x0060)  # 16 x 12-bit sample average
_CONFIG_SADCRES_12BIT_32S_17MS = const(0x0068)    # 32 x 12-bit sample average
_CONFIG_SADCRES_12BIT_64S_34MS = const(0x0070)    # 64 x 12-bit sample average
_CONFIG_SADCRES_12BIT_128S_69MS = const(0x0078)   # 128 x 12-bit sample average

_CONFIG_MODE_MASK = const(0x0007)  # Operating Mode Mask
_CONFIG_MODE_POWERDOWN = const(0x0000)
_CONFIG_MODE_SVOLT_TRIGGERED = const(0x0001)
_CONFIG_MODE_BVOLT_TRIGGERED = const(0x0002)
_CONFIG_MODE_SANDBVOLT_TRIGGERED = const(0x0003)
_CONFIG_MODE_ADCOFF = const(0x0004)
_CONFIG_MODE_SVOLT_CONTINUOUS = const(0x0005)
_CONFIG_MODE_BVOLT_CONTINUOUS = const(0x0006)
_CONFIG_MODE_SANDBVOLT_CONTINUOUS = const(0x0007)

# SHUNT VOLTAGE REGISTER (R)
_REG_SHUNTVOLTAGE = const(0x01)

# BUS VOLTAGE REGISTER (R)
_REG_BUSVOLTAGE = const(0x02)

# POWER REGISTER (R)
_REG_POWER = const(0x03)

# CURRENT REGISTER (R)
_REG_CURRENT = const(0x04)

# CALIBRATION REGISTER (R/W)
_REG_CALIBRATION = const(0x05)
# pylint: enable=bad-whitespace


def _to_signed(num):
    if num > 0x7FFF:
        num -= 0x10000
    return num


class INA219:
    """Driver for the INA219 current sensor"""
    def __init__(self, i2c_device, addr=0x40):
        self.i2c_device = i2c_device

        self.i2c_addr = addr
        self.buf = bytearray(2)
        # Multiplier in mA used to determine current from raw reading
        self._current_lsb = 0
        # Multiplier in W used to determine power from raw reading
        self._power_lsb = 0

        # Set chip to known config values to start
        self._cal_value = 4096
        self.set_calibration_32V_2A()

    def _write_register(self, reg, value):
        self.buf[0] = (value >> 8) & 0xFF
        self.buf[1] = value & 0xFF
        self.i2c_device.writeto_mem(self.i2c_addr, reg, self.buf)

    def _read_register(self, reg):
        self.i2c_device.readfrom_mem_into(self.i2c_addr, reg & 0xff, self.buf)
        value = (self.buf[0] << 8) | (self.buf[1])
        return value

    @property
    def shunt_voltage(self):
        """The shunt voltage (between V+ and V-) in Volts (so +-.327V)"""
        value = _to_signed(self._read_register(_REG_SHUNTVOLTAGE))
        # The least signficant bit is 10uV which is 0.00001 volts
        return value * 0.00001

    @property
    def bus_voltage(self):
        """The bus voltage (between V- and GND) in Volts"""
        raw_voltage = self._read_register(_REG_BUSVOLTAGE)

        # Shift to the right 3 to drop CNVR and OVF and multiply by LSB
        # Each least signficant bit is 4mV
        voltage_mv = _to_signed(raw_voltage >> 3) * 4
        return voltage_mv * 0.001

    @property
    def current(self):
        """The current through the shunt resistor in milliamps."""
        # Sometimes a sharp load will reset the INA219, which will
        # reset the cal register, meaning CURRENT and POWER will
        # not be available ... athis by always setting a cal
        # value even if it's an unfortunate extra step
        self._write_register(_REG_CALIBRATION, self._cal_value)

        # Now we can safely read the CURRENT register!
        raw_current = _to_signed(self._read_register(_REG_CURRENT))
        return raw_current * self._current_lsb

    def set_calibration_32V_2A(self):  # pylint: disable=invalid-name
        """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"""
        # By default we use a pretty huge range for the input voltage,
        # which probably isn't the most appropriate choice for system
        # that don't use a lot of power.  But all of the calculations
        # are shown below if you want to change the settings.  You will
        # also need to change any relevant register settings, such as
        # setting the VBUS_MAX to 16V instead of 32V, etc.

        # VBUS_MAX = 32V    (Assumes 32V, can also be set to 16V)
        # VSHUNT_MAX = 0.32 (Assumes Gain 8, 320mV, can also be
        #                    0.16, 0.08, 0.04)
        # RSHUNT = 0.1      (Resistor value in ohms)

        # 1. Determine max possible current
        # MaxPossible_I = VSHUNT_MAX / RSHUNT
        # MaxPossible_I = 3.2A

        # 2. Determine max expected current
        # MaxExpected_I = 2.0A

        # 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
        # MinimumLSB = MaxExpected_I/32767
        # MinimumLSB = 0.000061              (61uA per bit)
        # MaximumLSB = MaxExpected_I/4096
        # MaximumLSB = 0,000488              (488uA per bit)

        # 4. Choose an LSB between the min and max values
        #    (Preferrably a roundish number close to MinLSB)
        # CurrentLSB = 0.0001 (100uA per bit)
        self._current_lsb = .1  # Current LSB = 100uA per bit

        # 5. Compute the calibration register
        # Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
        # Cal = 4096 (0x1000)

        self._cal_value = 4096

        # 6. Calculate the power LSB
        # PowerLSB = 20 * CurrentLSB
        # PowerLSB = 0.002 (2mW per bit)
        self._power_lsb = .002  # Power LSB = 2mW per bit

        # 7. Compute the maximum current and shunt voltage values before
        #    overflow
        #
        # Max_Current = Current_LSB * 32767
        # Max_Current = 3.2767A before overflow
        #
        # If Max_Current > Max_Possible_I then
        #    Max_Current_Before_Overflow = MaxPossible_I
        # Else
        #    Max_Current_Before_Overflow = Max_Current
        # End If
        #
        # Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
        # Max_ShuntVoltage = 0.32V
        #
        # If Max_ShuntVoltage >= VSHUNT_MAX
        #    Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
        # Else
        #    Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
        # End If

        # 8. Compute the Maximum Power
        # MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
        # MaximumPower = 3.2 * 32V
        # MaximumPower = 102.4W

        # Set Calibration register to 'Cal' calculated above
        self._write_register(_REG_CALIBRATION, self._cal_value)

        # Set Config register to take into account the settings above
        config = (_CONFIG_BVOLTAGERANGE_32V |
                  _CONFIG_GAIN_8_320MV |
                  _CONFIG_BADCRES_12BIT |
                  _CONFIG_SADCRES_12BIT_1S_532US |
                  _CONFIG_MODE_SANDBVOLT_CONTINUOUS)
        self._write_register(_REG_CONFIG, config)

    def set_calibration_32V_1A(self):  # pylint: disable=invalid-name
        """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."""
        # By default we use a pretty huge range for the input voltage,
        # which probably isn't the most appropriate choice for system
        # that don't use a lot of power.  But all of the calculations
        # are shown below if you want to change the settings.  You will
        # also need to change any relevant register settings, such as
        # setting the VBUS_MAX to 16V instead of 32V, etc.

        # VBUS_MAX = 32V    (Assumes 32V, can also be set to 16V)
        # VSHUNT_MAX = 0.32 (Assumes Gain 8, 320mV, can also be
        #                    0.16, 0.08, 0.04)
        # RSHUNT = 0.1      (Resistor value in ohms)

        # 1. Determine max possible current
        # MaxPossible_I = VSHUNT_MAX / RSHUNT
        # MaxPossible_I = 3.2A

        # 2. Determine max expected current
        # MaxExpected_I = 1.0A

        # 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
        # MinimumLSB = MaxExpected_I/32767
        # MinimumLSB = 0.0000305             (30.5uA per bit)
        # MaximumLSB = MaxExpected_I/4096
        # MaximumLSB = 0.000244              (244uA per bit)

        # 4. Choose an LSB between the min and max values
        #    (Preferrably a roundish number close to MinLSB)
        # CurrentLSB = 0.0000400 (40uA per bit)
        self._current_lsb = 0.04  # In milliamps

        # 5. Compute the calibration register
        # Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
        # Cal = 10240 (0x2800)

        self._cal_value = 10240

        # 6. Calculate the power LSB
        # PowerLSB = 20 * CurrentLSB
        # PowerLSB = 0.0008 (800uW per bit)
        self._power_lsb = 0.0008

        # 7. Compute the maximum current and shunt voltage values before
        #    overflow
        #
        # Max_Current = Current_LSB * 32767
        # Max_Current = 1.31068A before overflow
        #
        # If Max_Current > Max_Possible_I then
        #    Max_Current_Before_Overflow = MaxPossible_I
        # Else
        #    Max_Current_Before_Overflow = Max_Current
        # End If
        #
        # ... In this case, we're good though since Max_Current is less than
        #     MaxPossible_I
        #
        # Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
        # Max_ShuntVoltage = 0.131068V
        #
        # If Max_ShuntVoltage >= VSHUNT_MAX
        #    Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
        # Else
        #    Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
        # End If

        # 8. Compute the Maximum Power
        # MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
        # MaximumPower = 1.31068 * 32V
        # MaximumPower = 41.94176W

        # Set Calibration register to 'Cal' calculated above
        self._write_register(_REG_CALIBRATION, self._cal_value)

        # Set Config register to take into account the settings above
        config = (_CONFIG_BVOLTAGERANGE_32V |
                  _CONFIG_GAIN_8_320MV |
                  _CONFIG_BADCRES_12BIT |
                  _CONFIG_SADCRES_12BIT_1S_532US |
                  _CONFIG_MODE_SANDBVOLT_CONTINUOUS)
        self._write_register(_REG_CONFIG, config)

    def set_calibration_16V_400mA(self):  # pylint: disable=invalid-name
        """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."""
        # Calibration which uses the highest precision for
        # current measurement (0.1mA), at the expense of
        # only supporting 16V at 400mA max.

        # VBUS_MAX = 16V
        # VSHUNT_MAX = 0.04          (Assumes Gain 1, 40mV)
        # RSHUNT = 0.1               (Resistor value in ohms)

        # 1. Determine max possible current
        # MaxPossible_I = VSHUNT_MAX / RSHUNT
        # MaxPossible_I = 0.4A

        # 2. Determine max expected current
        # MaxExpected_I = 0.4A

        # 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
        # MinimumLSB = MaxExpected_I/32767
        # MinimumLSB = 0.0000122              (12uA per bit)
        # MaximumLSB = MaxExpected_I/4096
        # MaximumLSB = 0.0000977              (98uA per bit)

        # 4. Choose an LSB between the min and max values
        #    (Preferrably a roundish number close to MinLSB)
        # CurrentLSB = 0.00005 (50uA per bit)
        self._current_lsb = 0.05  # in milliamps

        # 5. Compute the calibration register
        # Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
        # Cal = 8192 (0x2000)

        self._cal_value = 8192

        # 6. Calculate the power LSB
        # PowerLSB = 20 * CurrentLSB
        # PowerLSB = 0.001 (1mW per bit)
        self._power_lsb = 0.001

        # 7. Compute the maximum current and shunt voltage values before
        #    overflow
        #
        # Max_Current = Current_LSB * 32767
        # Max_Current = 1.63835A before overflow
        #
        # If Max_Current > Max_Possible_I then
        #    Max_Current_Before_Overflow = MaxPossible_I
        # Else
        #    Max_Current_Before_Overflow = Max_Current
        # End If
        #
        # Max_Current_Before_Overflow = MaxPossible_I
        # Max_Current_Before_Overflow = 0.4
        #
        # Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
        # Max_ShuntVoltage = 0.04V
        #
        # If Max_ShuntVoltage >= VSHUNT_MAX
        #    Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
        # Else
        #    Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
        # End If
        #
        # Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
        # Max_ShuntVoltage_Before_Overflow = 0.04V

        # 8. Compute the Maximum Power
        # MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
        # MaximumPower = 0.4 * 16V
        # MaximumPower = 6.4W

        # Set Calibration register to 'Cal' calculated above
        self._write_register(_REG_CALIBRATION, self._cal_value)

        # Set Config register to take into account the settings above
        config = (_CONFIG_BVOLTAGERANGE_16V |
                  _CONFIG_GAIN_1_40MV |
                  _CONFIG_BADCRES_12BIT |
                  _CONFIG_SADCRES_12BIT_1S_532US |
                  _CONFIG_MODE_SANDBVOLT_CONTINUOUS)
        self._write_register(_REG_CONFIG, config)
复制代码

参考：NA219 Raspberry Pi Pico with micropython code for measuring voltage and current .

终端打印

'''
Name: INA219 demo, print voltage and current
Version: v1.0
Date: 2025.05
Author: ljl
Other: Shell print voltage and current tested by INA219 sensor.
'''

from machine import I2C, Pin
from ina219 import INA219
from time import sleep
import utime

# I2C Initialization (SDA: GP0, SCL: GP1)
i2c = I2C(0, scl=Pin(1), sda=Pin(0), freq=400000)

# I2C-Scan - searching for connected Devices on the I2C Bus
devices = i2c.scan()
if devices:
    print("I2C devices found:", [hex(device) for device in devices])
else:
    print("No I2C devices found. Check connections!")
    while True:
        pass


# INA219-Sensor Initialization
ina = INA219(i2c)
ina.set_calibration_32V_1A()

# main loop
while True:
    try:
        current = ina.current
        voltage = ina.bus_voltage
        
        if current <= 0.05:
            current = 0
            
        if voltage <= 0.05:
            voltage = 0
            
        print("{:.2f} mA  {:.2f} V".format(current, voltage))
        utime.sleep_ms(250)
        
    except Exception as e:
        print("Error reading INA219:", e)
        
    sleep(1)OLED 显示'''
Name: INA219 demo, print and display voltage and current
Version: v1.0
Date: 2025.05
Author: ljl
Other: Shell print and OLED display voltage and current tested by INA219 sensor.
'''

from machine import I2C, Pin
from ina219 import INA219
from time import sleep
import utime
import ssd1306

# ==== Initialized IIC OLED ====
i2c = I2C(0, scl=Pin(5), sda=Pin(4),freq=400000)
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

#i2c = I2C(0, scl=Pin(1), sda=Pin(0),freq=400000)
# I2C-Scan - searching for connected Devices on the I2C Bus
devices = i2c.scan()
if devices:
    print("I2C devices found:", [hex(device) for device in devices])
else:
    print("No I2C devices found. Check connections!")
    while True:
        pass


# INA219-Sensor Initialization
ina = INA219(i2c)
ina.set_calibration_32V_1A()

def display_VC(voltage,current): # voltage and current
    oled.fill(0)  # 清屏
    oled.text("Voltage: ", 0, 0)
    oled.text("{:.2f} V".format(voltage), 0, 15)
    oled.text("Current: ", 0, 35)
    oled.text("{:.2f} mA".format(current), 0, 50)
    oled.show()
# main loop
while True:
    try:
        current = ina.current
        voltage = ina.bus_voltage
        
        if current <= 0.05:
            current = 0
            
        if voltage <= 0.05:
            voltage = 0
            
        print("{:.2f} mA  {:.2f} V".format(current, voltage))
        display_VC(voltage,current);
        utime.sleep_ms(250)
        
    except Exception as e:
        print("Error reading INA219:", e)
        
    sleep(1)
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LabVIEW上位机

介绍了 LabVIEW 上位机向单片机发送串口指令，获取 INA219 传感器电压和电流数据，并绘制功率数值演化曲线。

代码

串口以十六进制发送 55 AA 10 或 55 AA 11 分别获得电压和电流数值。

'''
Name: INA219 demo, print and UART voltage and current
Version: v1.0
Date: 2025.05
Author: ljl
Other: UART send voltage and current which data tested by INA219 sensor.
'''

from machine import Pin, I2C, UART
from ina219 import INA219
import utime
import ssd1306

# ==== Initialized IIC OLED ====
i2c = I2C(0, scl=Pin(5), sda=Pin(4),freq=400000)
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

#i2c = I2C(0, scl=Pin(1), sda=Pin(0),freq=400000)
# I2C-Scan - searching for connected Devices on the I2C Bus
devices = i2c.scan()
if devices:
    print("I2C devices found:", [hex(device) for device in devices])
else:
    print("No I2C devices found. Check connections!")
    while True:
        pass

# INA219-Sensor Initialization
ina = INA219(i2c)
ina.set_calibration_32V_1A()

# Initialize UART (change pins as needed for your board)
uart = machine.UART(1, baudrate=9600, tx=Pin(8), rx=Pin(9))
comdata = bytearray(3)

def display_VC(voltage,current): # voltage and current
    oled.fill(0)  # 清屏
    oled.text("Voltage: ", 0, 0)
    oled.text("{:.2f} V".format(voltage), 0, 15)
    oled.text("Current: ", 0, 35)
    oled.text("{:.2f} mA".format(current), 0, 50)
    oled.show()

def receive_data():
    for i in range(3):
        while not uart.any():  # Wait for data to be available
            pass
        comdata = uart.read(1)[0]  # Read one byte
        utime.sleep_ms(2)  # Small delay between bytes

def test_do_data():
    if comdata[0] == 0x55 and comdata[1] == 0xAA:
        try:
            if comdata[2] == 0x10:
                voltage = ina.bus_voltage
                if voltage <= 0.05:
                    voltage = 0
                uart.write("{:.2f}\r\n".format(voltage))
            elif comdata[2] == 0x11:
                current = ina.current
                if current <= 0.05:
                    current = 0
                uart.write("{:.2f}\r\n".format(current))
        except Exception as e:
                uart.write("Error reading sensor.\r\n")

# Serial acquire data
def uart_acquire():
    if uart.any() >= 3:
        receive_data()
        test_do_data()
    utime.sleep_ms(0)  # Small delay to prevent busy-wait

# main loop
while True:
    uart_acquire()
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