python pyserial

Question

I am triggering a device called olfactometer from python 2.7 anaconda spyder 64 bit. There are eight solenoid TTL valves in that olfactometer. If I want to switch the status of that valve I just have to write below-mentioned code.

import serial
import time

port = serial.Serial("COM3", 19200, timeout=0.5)
#turn on port 2, sleep 2 seconds, turn off port 2
port.write(b"\nF2\r")  # if opened then close port 2
time.sleep(2.0)
port.write(b"\nF2\r")  # if closed then open port 2


#close the port
port.close()

I would like to know, is it possible to give port 2 specific values from 0 or 1?

for example

if 'e' in keypress: 
    # it must open the port 2
if 'i' in keypress:
    # it must close the port 2

What should I do to perform the test in an above-mentioned way? Thank you in advance! - Ravi

Answer 1

One way you can capture input is with the raw_input built-in function ( input in Python3). For example

port = serial.Serial("COM3", 19200, timeout=0.5)

prompt = 'Press "e" to open, "i" to close, and "q" to quit: '
keypress = raw_input(prompt)
while keypress != 'q':
    if keypress == 'e':
        port.write(b"\nF2\r")  # if closed then open port 2
        print('Opened')
    elif keypress == 'i':
        port.write(b"\nF2\r")  # if opened then close port 2
        print('Closed')
    # prompt again    
    keypress = raw_input(prompt)

port.close()