volume.py

#!/usr/bin/python
#Control MPD Client volume using a physical rotary encoder
#pip install mopidy-spotify

from RPi import GPIO
from time import sleep
import os

clk = 17
dt = 27

GPIO.setmode(GPIO.BCM)
GPIO.setup(clk, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
GPIO.setup(dt, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

counter = 0
clkLastState = GPIO.input(clk)
currVolume = 50

try:
        while True:
                clkState = GPIO.input(clk)
                dtState = GPIO.input(dt)
                if clkState != clkLastState:
                        if dtState != clkState:
                                currVolume += 5
                        else:
                                currVolume -= 5
#                       print currVolume
                        os.system("mpc volume " + str(currVolume))
                        clkLastState = clkState
                        sleep(0.01)
finally:
        GPIO.cleanup