midi switch

#!/usr/bin/env python
import time
import pigpio # http://abyz.co.uk/rpi/pigpio/
GPIO=4

SWITCH1 = 17 #(P11)

pi = pigpio.pi()                 # Connect to local Pi.
pi.set_mode(GPIO, pigpio.OUTPUT) # Set GPIO as an output.

pi.set_mode(17, pigpio.INPUT)   #Set Pin 11 as input
pi.set_pull_up_down(17, pigpio.PUD_UP)  #with pull-up

pi.wave_add_new()                # Clear any leftover data.
pi.wave_add_serial(GPIO, 31250, chr(0x90)+chr(0x43)+chr(0x40))
wid = pi.wave_create()           # Create wave from added data, get id.

while pi.read(17) == 1: #Wait while switch is not pressed
    time.sleep(0.1)

for i in range(1):
   pi.wave_send_once(wid)        # Transmit wave data.
   while pi.wave_tx_busy():      # Wait for wave end, then repeat.
      time.sleep(0.01)
pi.wave_delete(wid)              # Delete wave to release used resources.
pi.stop()