问题
I'am Trying to Communicate with Arduino using serial communication in python. There is this program from arduino https://www.arduino.cc/en/Tutorial/ReadASCIIString . Simply sending a " 120,200,100" to control 3 LEDS. When I tried it in python writing data to the arduino so simply
arduino.write(b'120,10,244\n')
and it works. But my main problem is that if I assigned those values to a variable which gets change through a GUI for example a PyQT slider which I'am planning to implement it on, How should I go about this?
How to output 3 integers assigned to variables->to csv -> bytes +\n
For example
P1 = self.PWM1horizontalSlider.value() # ASSUMING a value of 120
P2 = self.PWM2horizontalSlider.value() # ASSUMING a value of 200
P3 = self.PWM3horizontalSlider.value() # ASSUMING a value of 100
into b'120,200,100\n'
Read ASCII String Code
// pins for the LEDs:
const int redPin = 3;
const int greenPin = 5;
const int bluePin = 6;
void setup() {
// initialize serial:
Serial.begin(9600);
// make the pins outputs:
pinMode(redPin, OUTPUT);
pinMode(greenPin, OUTPUT);
pinMode(bluePin, OUTPUT);
}
void loop() {
// if there's any serial available, read it:
while (Serial.available() > 0) {
// look for the next valid integer in the incoming serial stream:
int red = Serial.parseInt();
// do it again:
int green = Serial.parseInt();
// do it again:
int blue = Serial.parseInt();
// look for the newline. That's the end of your sentence:
if (Serial.read() == '\n') {
// constrain the values to 0 - 255 and invert
// if you're using a common-cathode LED, just use "constrain(color, 0, 255);"
red = 255 - constrain(red, 0, 255);
green = 255 - constrain(green, 0, 255);
blue = 255 - constrain(blue, 0, 255);
// fade the red, green, and blue legs of the LED:
analogWrite(redPin, red);
analogWrite(greenPin, green);
analogWrite(bluePin, blue);
// print the three numbers in one string as hexadecimal:
Serial.print(red, HEX);
Serial.print(green, HEX);
Serial.println(blue, HEX);
}
}
}
回答1:
To answer your question, outside of the example:
p1 = 120
p2 = 200
p3 = 100
the_bytes = bytes(f'{p1},{p2},{p3}\n', 'utf-8')
This is assuming you want the bytes to use UTF-8 as an encoding, which is common, but something you'd want to check. It could also be something like cp1252 - more here https://docs.python.org/3/library/codecs.html#standard-encodings
You could then send the_bytes wherever you need them.
来源：https://stackoverflow.com/questions/54917671/python-3-csv-integers-to-bytes-n