Beetle 树莓派RP2350 - 便携INA219功率计
本帖最后由 无垠的广袤 于 2025-5-13 02:34 编辑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
名称功能描述
VCC电源正极（3.3~5.5V）
GND电源负极
SCLI2C时钟线
SDAI2C数据线
ADDRI2C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 = (value >> 8) & 0xFF
self.buf = 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 << 8) | (self.buf)
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)
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:", )
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:", )
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)
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:", )
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)# Read one byte
utime.sleep_ms(2)# Small delay between bytes
def test_do_data():
if comdata == 0x55 and comdata == 0xAA:
try:
if comdata == 0x10:
voltage = ina.bus_voltage
if voltage <= 0.05:
voltage = 0
uart.write("{:.2f}\r\n".format(voltage))
elif comdata == 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()
前面板
功能实现：
[*]配置串口
[*]运行程序
[*]点击 Start 开始采集数据
[*]点击 Stop 停止采集
[*]点击 Terminate 终止程序。
程序框图
Page 1
Page 2
效果
OLED 显示
终端打印
测量电机功率
在完成空载情况下功率测量的基础上，考虑加负载的情况。
负载可以是功率器件、电阻、电机等，可以较为明显地反映系统功率的变化。
硬件连接
[*] GP4 ---- SDA (INA219)
[*] GP5 ---- SCL (INA219)
[*] GP8 ---- RXD (CH340)
[*] GP9 ---- TXD (CH340)
[*] GP4 ---- SDA (OLED_SSD1306)
[*] GP5 ---- SCL (OLED_SSD1306)
[*] GND (INA219) ---- Negative (Motor) ---- Negative (Power Supply)
[*] IN+ (INA219) ---- Positive (Power Supply)
[*] IN- (INA219) ---- Positive (Motor)
实物连接
通过对比供电接口处的电压和电流值，INA219传感器可以获得更精确的功率值。
动态演示
LabVIEW 上位机演示
演示了开启电机瞬间的电压、电流以及功率的变化情况。
分析
可以看出，直接采集 INA219 传感器获取的数据存在较大的抖动，可采取 滤波算法 （软件滤波、低通滤波、滑动平均等）进行参数优化，使输出功率更为稳定、更符合实际情况。
总结
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、功率数据监测的项目设计，为 Beetle RP2350 开发板的开发设计和产品应用提供了参考。
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