python3 pySerial TypeError: unicode strings are not supported, please encode to bytes:

python-3.x arduino pyserial
Nik Hendricks picture Nik Hendricks · Feb 26, 2016 · Viewed 86.1k times · Source

In Python 3 I imported the pySerial library so I could communicate with my Arduino Uno by serial commands.
It worked very well in Python 2.7 but in Python 3 I keep running into a error it says this

TypeError: unicode strings are not supported, please encode to bytes: 'allon'

In Python 2.7 the only thing I did differently is use raw_input but I don't know what is happening in Python 3. Here is my code 

import serial, time
import tkinter
import os

def serialcmdw():
    os.system('clear')
    serialcmd = input("serial command: ")
    ser.write (serialcmd)

serialcmdw()

ser = serial.Serial()
os.system('clear')
ser.port = "/dev/cu.usbmodem4321"
ser.baudrate = 9600
ser.open()
time.sleep(1)
serialcmdw()

Answer

nsr picture nsr · Feb 26, 2016

Encode your data which you are writing to serial,in your case "serialcmd" to bytes.try the following :

ser.write(serialcmd.encode())

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