基于Windows IoT的树莓派3与Arduino I2C写数据实现求助

Hey there! Let's work through this I2C write issue between your Raspberry Pi 3 running Windows IoT and your Arduino slave. Since you've already got reading working, you're halfway there—let's get that write functionality sorted out.

First: Make Sure Your Arduino Slave is Configured to Receive Data #

The Arduino needs to listen for incoming I2C writes from the Pi. Use the Wire library's onReceive callback to handle data when it arrives. Here's a minimal working example:

#include <Wire.h>

// 🔔 This address MUST match the one you use in your Windows IoT code!
#define ARDUINO_SLAVE_ADDRESS 0x08

void setup() {
  // Initialize I2C as a slave with our chosen address
  Wire.begin(ARDUINO_SLAVE_ADDRESS);
  // Register a callback function to run when data is received
  Wire.onReceive(receivePiData);
  // Start serial monitor to debug received data
  Serial.begin(9600);
}

void loop() {
  // Nothing needed here—callback handles incoming data
  delay(100);
}

// Callback function to process data from the Pi
void receivePiData(int byteCount) {
  while (Wire.available()) {
    // Read one byte at a time (adjust this based on your data format)
    char receivedByte = Wire.read();
    Serial.print("Received from Pi: ");
    Serial.println(receivedByte);
    
    // Add your logic here—e.g., toggle an LED, store a value, etc.
  }
}

Key notes here:

• Double-check the slave address matches exactly between Arduino and Windows IoT code.
• Use the Arduino Serial Monitor to verify if data is coming in—this is critical for debugging.

Second: Implement I2C Write on Windows IoT (Raspberry Pi) #

Since you're using a TextBlock, I assume you're working with a UWP app. Here's how to set up I2C write functionality in C#:

1. Add I2C Permission to Your App Manifest #

First, open Package.appxmanifest and add the I2C capability (without this, your app won't have access to the bus):

<Capabilities>
    <DeviceCapability Name="i2c" />
</Capabilities>

2. Initialize I2C and Write Data #

Here's the code to initialize the I2C controller and send data to the Arduino:

using Windows.Devices.I2c;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

public sealed partial class MainPage : Page
{
    private I2cDevice _arduinoI2cDevice;
    // 🔔 Match this address to the one in your Arduino code!
    private const int ArduinoSlaveAddress = 0x08;

    public MainPage()
    {
        this.InitializeComponent();
        // Initialize I2C when the page loads
        _ = InitializeI2cAsync();
    }

    private async Task InitializeI2cAsync()
    {
        try
        {
            // Get the default I2C controller on the Pi
            var i2cController = await I2cController.GetDefaultAsync();
            if (i2cController == null)
            {
                StatusTextBlock.Text = "No I2C controller found on the Pi!";
                return;
            }

            // Configure I2C settings (use StandardMode first for compatibility)
            var i2cSettings = new I2cConnectionSettings(ArduinoSlaveAddress)
            {
                BusSpeed = I2cBusSpeed.StandardMode // 100kHz, matches Arduino's default
            };

            // Connect to the Arduino slave
            _arduinoI2cDevice = i2cController.GetDevice(i2cSettings);
            StatusTextBlock.Text = "I2C connection initialized successfully";
        }
        catch (Exception ex)
        {
            StatusTextBlock.Text = $"I2C init failed: {ex.Message}";
        }
    }

    // Example: Trigger write when a button is clicked
    private async void SendDataButton_Click(object sender, RoutedEventArgs e)
    {
        if (_arduinoI2cDevice == null)
        {
            StatusTextBlock.Text = "I2C not initialized—check connections!";
            return;
        }

        try
        {
            // Convert your message to a byte array (adjust based on your data needs)
            string messageToSend = "Hello from Pi!";
            byte[] writeBuffer = System.Text.Encoding.ASCII.GetBytes(messageToSend);

            // Send the data to Arduino
            await _arduinoI2cDevice.WriteAsync(writeBuffer);
            StatusTextBlock.Text = $"Sent data: {messageToSend}";
        }
        catch (Exception ex)
        {
            StatusTextBlock.Text = $"Write failed: {ex.Message}";
        }
    }
}

Key notes for the Windows IoT side:

• Use StandardMode (100kHz) first—Arduino's default I2C speed is 100kHz, mismatched speeds can cause write failures.
• Always wrap I2C operations in try/catch blocks to catch errors like permission issues or loose connections.

Third: Debugging Tips if It Still Fails #

If you're still having issues, work through these checks:

• Verify Wiring: Ensure SDA (Pi GPIO2 ↔ Arduino A4), SCL (Pi GPIO3 ↔ Arduino A5), and GND are connected securely. No common ground = no reliable communication.
• Scan for I2C Devices: Run an I2C scanner on the Pi (or Arduino) to confirm the Arduino's slave address is visible. If it's not, your wiring or Arduino setup is wrong.
• Check Serial Monitor: On the Arduino side, open the Serial Monitor (9600 baud) to see if data is being received. If you see nothing, the issue is on the Pi's write side or wiring.
• Check for Address Conflicts: Make sure no other devices on the I2C bus are using the same address as your Arduino.

内容的提问来源于stack exchange，提问作者user6480540