# Metronome3x.py
#
# DEMO simple metronome that exploits a minor flaw in the /dev/audio and /dev/dsp devices inside Linux.
# It can tick at around 30 to 400 beats per minute. This minimal code can be improved upon to give
# greater accuracy, range and appearance on screen if required.
#
# Original copyright, (C)2007-2012, B.Walker, G0LCU. Now issued as Public Domain and you may do with
# it as you please.
#
# There is a small flaw that uses the Ctrl-C part of the code. I'll let the big guns tell you users
# that can't find it what it is. It is not a bug as such, but it is a flaw.
#
# Tested on an HP Notebook with Debian 6.0.0 and Python 3.1.3 and an Acer Aspire One Netbook with
# PCLinuxOS 2009 and Python 3.2.1.
# To run just type:-
#
# >>> exec(open("/absolute/path/to/Metronome3x.py").read())<RETURN/ENTER>
#
# And away you go...
#
# $VER: Metronome3x.py_Version_0.00.10_(C)2007-2012_B.Walker_G0LCU.
#
# Enjoy finding simple solutions to often very difficult problems...
# The only import(s) for this DEMO...
import time
import os
def main():
while 1:
# the _variable_ listing...
# "n" is throw away integer number and purposely reused.
# "beatstring" is the inputted string and is also reused.
# "beat" is the floating point number from about 0.x to 1.x generated from the inputted data.
#
# The standard Linux clear screen cmmand.
n=os.system("clear")
# Set up a basic user screen/window.
print("\nPython 3.x.x simple metronome for the Linux platform.\n")
print("(C)2007-2012, B.Walker, G0LCU. Issued as Public Domain.\n")
beatstring=input("Enter any whole number from 30 to 400 (bpm), (QUIT or EXIT to Quit):- ")
# Allow a means of quitting the DEMO.
if beatstring=="QUIT" or beatstring=="EXIT": break
# Don't allow any errors...
if len(beatstring)>=4: beatstring="100"
if len(beatstring)<=1: beatstring="100"
n=0
while n<=(len(beatstring)-1):
if beatstring[n]>=chr(48) and beatstring[n]<=chr(57): n=n+1
else: beatstring="100"
n=int(beatstring)
if n<=30: n=30
if n>=400: n=400
# Convert this integer "n" back to the "beatstring" string...
beatstring=str(n)
# Now convert to the floating point value for the time.sleep() function.
beat=((60/n)-0.125)
print("\nApproximate beats per minute = "+beatstring+"...\n")
print("Press Ctrl-C to enter another speed...")
while 1:
# Write directly to the /dev/dsp device.
try:
audio=open("/dev/dsp", "wb")
audio.write(b"\x00\xFF")
audio.close()
time.sleep(beat)
# There is a flaw here, I'll let you big guns find it... ;o)
# Note it is NOT really a bug!
except KeyboardInterrupt: break
main()
# End of the Metronome3x.py code.
# Enjoy finding simple solutions to often very difficult problems...
Diff to Previous Revision
--- revision 1 2012-05-18 19:26:30
+++ revision 2 2012-05-18 19:30:04
@@ -37,46 +37,7 @@
n=os.system("clear")
# Set up a basic user screen/window.
print("\nPython 3.x.x simple metronome for the Linux platform.\n")
- print("
-# Metronome3x.py
-#
-# DEMO simple metronome that exploits a minor flaw in the /dev/audio and /dev/dsp devices inside Linux.
-# It can tick at around 30 to 400 beats per minute. This minimal code can be improved upon to give
-# greater accuracy, range and appearance on screen if required.
-#
-# Original copyright, (C)2007-2012, B.Walker, G0LCU. Now issued as Public Domain and you may do with
-# it as you please.
-#
-# There is a small flaw that uses the Ctrl-C part of the code. I'll let the big guns tell you users
-# that can't find it what it is. It is not a bug as such, but it is a flaw.
-#
-# Tested on an HP Notebook with Debian 6.0.0 and Python 3.1.3 and an Acer Aspire One Netbook with
-# PCLinuxOS 2009 and Python 3.2.1.
-# To run just type:-
-#
-# >>> exec(open("/absolute/path/to/Metronome3x.py").read())<RETURN/ENTER>
-#
-# And away you go...
-#
-# $VER: Metronome3x.py_Version_0.00.10_(C)2007-2012_B.Walker_G0LCU.
-#
-# Enjoy finding simple solutions to often very difficult problems...
-
-# The only import(s) for this DEMO...
-import time
-import os
-
-def main():
- while 1:
- # the _variable_ listing...
- # "n" is throw away integer number and purposely reused.
- # "beatstring" is the inputted string and is also reused.
- # "beat" is the floating point number from about 0.x to 1.x generated from the inputted data.
- #
- # The standard Linux clear screen cmmand.
- n=os.system("clear")
- # Set up a basic user screen/window.
- print("\(C)2007-2012, B.Walker, G0LCU. Issued as Public Domain.\n")
+ print("(C)2007-2012, B.Walker, G0LCU. Issued as Public Domain.\n")
beatstring=input("Enter any whole number from 30 to 400 (bpm), (QUIT or EXIT to Quit):- ")
# Allow a means of quitting the DEMO.
if beatstring=="QUIT" or beatstring=="EXIT": break
