Arduino and Python

hi everybody i'm trying to communicate the arduino with python and i have some problems.

the idea is to turn on a led and then turn it off
this is the arduino code(Blink example)

const int ledPin = 13; // the pin that the LED is attached to
int incomingByte;      // a variable to read incoming serial data into

void setup() {
  // initialize serial communication:
  Serial.begin(9600);
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // see if there's incoming serial data:
  if (Serial.available() > 0) {
    // read the oldest byte in the serial buffer:
    incomingByte = Serial.read();
    // if it's a capital H (ASCII 72), turn on the LED:
    if (incomingByte == 'H') {
      digitalWrite(ledPin, HIGH);
    } 
    // if it's an L (ASCII 76) turn off the LED:
    if (incomingByte == 'L') {
      digitalWrite(ledPin, LOW);
    }
  }
}

this is the python code

import serial
from time   import sleep
serialport = serial.Serial('COM3', 9600)
serialport.setDTR(False) # Drop DTR
sleep(0.022)    # Read somewhere that 22ms is what the UI does.
serialport.setDTR(True)  # UP the DTR back 
while 1:
     serialport.write('H')
     sleep(1)
     serialport.write('L')     

serialport.close()

the led is always on... what i'm doing wrong?

serialport.write('H')
     sleep(1)
     serialport.write('L')

I Think you need another sleep, ie

serialport.write('H')
     sleep(1)
     serialport.write('L')
     [glow]sleep(1)[/glow]

thanks

it worked perfectly :slight_smile: