Arduino 和 Python Pyserial 通信

Question

我正在尝试编写一个代码，允许我使用 Python 代码将输出发送到我的微控制器（Sparkfun Redboard）。

我想传递不同的变量（CMJ 或 SJ），如果传递 CMJ，我希望内置 LED 打开（并保持打开状态）；如果传递 SJ，则关闭（并保持关闭状态）。如果通过了其他任何内容，我还想打印（“无效”）。

这是我的Python代码：

import serial
import time

# Setup serial communication
serialcomm = serial.Serial("COM4", 500000)
serialcomm.timeout = 1

# Define your variable
activity = "CMJ"  # Change this to "CMJ" or anything else to test different scenarios

while True:
    if activity == "done":
        print("finished")
        break
    elif activity == "CMJ":
        command = "on"
    elif activity == "SJ":
        command = "off"
    else:
        command = "invalid"

    # Send the command to the Arduino
    serialcomm.write(('command'+'\n').encode())  # Send command with newline character

    # Wait for a moment to ensure the command is processed
    time.sleep(0.5)

    # Read and print the response from the Arduino
    response = serialcomm.readline().decode('ascii').strip()
    print(response)

    # Close the serial communication when done
    serialcomm.close()

和我的 Arduino 代码：

String InBytes;

void setup() {
  Serial.begin(500000); // Ensure this matches the Python code
  pinMode(LED_BUILTIN, OUTPUT); // Set the LED pin as an output
  digitalWrite(LED_BUILTIN, LOW); // Ensure the LED is off initially
}

void loop() {
  if (Serial.available() > 0) {
    InBytes = Serial.readStringUntil('\n'); // Read the incoming string until newline
    InBytes.trim(); // Remove any leading or trailing whitespace/newline characters
    
    // Debugging output
    Serial.print("Received command: ");
    Serial.println(InBytes);

    if (InBytes == "on") {
      digitalWrite(LED_BUILTIN, HIGH); // Turn the LED on
      Serial.write("Led on"); // Send a response back
    } else if (InBytes == "off") {
      digitalWrite(LED_BUILTIN, LOW); // Turn the LED off
      Serial.write("Led off"); // Send a response back
    } else {
      Serial.write("Invalid"); // Handle invalid commands
    }
  }
}

结果是，无论我传递什么变量（CMJ、SJ或其他任何变量），LED都会闪烁一秒钟。代码一定有问题，但无法弄清楚。

Answer 1

仔细查看您的代码，错误在于您正在使用

('command'+'\n').encode()

。在这种情况下，arduino 将获取字符串

"command\n"

。

要修复它，请在 python 端使用它：

# Setup serial communication
serialcomm = serial.Serial("COM4", 500000)
serialcomm.timeout = 1
# Define your variable
activity = "CMJ"  # Change this to "CMJ" or anything else to test different scenarios
while True:
    try:
        if activity == "done":
            print("finished")
            break
        elif activity == "CMJ":
            command = "on"
        elif activity == "SJ":
            command = "off"
        else:
            command = "invalid"
        command += "\n"
        serialcomm.write(command.encode())  # Send command with newline character
        time.sleep(0.5)
        response = serialcomm.readline().decode('ascii').strip()
        print(response)
    except KeyboardInterrupt:
        print("Goodbye!")
        serialcomm.close()
        break

请注意，我添加了一个

try:except

语句，像这样，循环将继续，直到有人使用

cntrl+c

，此时脚本将结束，

serialcomm

将被关闭。

希望这有帮助。

还有我这边的“证据”：

注意：确保除了 python 脚本之外，无法从其他任何地方访问 arduino。否则，串口是“打开”的，尝试在 python 中访问它会抛出权限错误。