AudioScope.py
I think this might be a first for both Python.
Initially uploaded to LXF, now also here under the MIT licence.
I am building a kids level seismometer and wanted to use standard Python inside Linux.
This DEMO code was my starter idea and looks as though using standard ASCII only might just work a real treat.
I've issued it to LXF under the MIT licence for future reasons.
It doesn't look much on screen except that the waveform(s) shown is/are a basic visual, electrical representation of your voice. ;o)
It is possible to link the earphone socket on this notebook to the mic input and start the Audio Function Generator, elsewhere in this site, in a separate Python terminal and see those waveforms inside the AudioScope.py`s own Python terminal.
This grabs a 1 second 8KB burst, and then displays it onto the Python terminal. The timebase, amplitude, trigger, single shot and others are not included but the main grab and display using /dev/dsp is shown. This can be made platform independent by changing the /dev/dsp to something external like the Arduino Dev Board. This uses STANDARD Python 2.5.x and later and tested on PCLinuxOS 2009 and Debian 6.0.0.
Enjoy finding simple solutions to often very difficult problems.
Bazza, G0LCU.
Download
Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 | #!/usr/bin/python
#
# AudioScope.py
#
# DEMO LF Audio Oscilloscope using /dev/dsp inside Linux.
# Original copyright, (C)2011, B.Walker, G0LCU.
# Initially issued to LXF under the MIT licence.
#
# The timebase runs vertically and the waveform amplitude horizontally.
# It grabs a sample for about 1 second and displays the results AFTER
# the sample; technically a basic LF Storage Audio Oscilloscope.
#
# The display only uses standard ASCII characters.
#
# To run just type from the prompt ">>>"...
# >>> execfile("/full/path/to/AudioScope.py")<RETURN/ENTER>
#
# Tested on Python 2.6.x only but should work on other versions of 2.x.x.
# Ensure /dev/dsp exists; if not install oss-compat from your distro`s
# repository. Also ensure the sound card is not already in use.
#
# Enjoy finding simple solutions to often very difficult problems... ;o)
#
# If you are just trying this out and have an internal mic, just talk
# loudly into the microphone and see your vocal wavefrom on screen...
# Needless to say using the external microphone input as an input this
# becomes a single channel uncalibrated LF Audio Oscilloscope.
#
# Press Ctrl-C to STOP.
# Import any necessary modules.
import os
# Do a basic screen clear.
os.system("clear")
# Turn the cursor off to look prettier... ;o)
os.system("setterm -cursor off")
def main():
# Set special variables global.
global audioscope
global chardisplay
global offset
global timebase
global record
# Known variables.
audioscope = 0
chardisplay = "(C)2011, B.Walker, G0LCU."
offset = 0
timebase = 1
record = "Initial issue to LXF under the MIT licence"
# Throw away local variables.
n = 0
while 1:
# Sample the microphone/external_microphone_input for approximately 1 second.
audio = file('/dev/dsp', 'rb')
record = audio.read(8192)
audio.close()
# This value points to a character in the 8192 byte string.
# "offset" can be any value from 0 to 191.
offset = 0
# Start the loop from character at position 0.
while offset <= 8191:
# Convert the character to a decimal number.
audioscope = ord(record[offset])
# Now convert to 6 bit depth to fit one terminal line.
audioscope = int(audioscope/4)
# This should never occur but don`t allow an error.
if audioscope >= 63: audioscope = 63
if audioscope <= 0: audioscope = 0
# Invert to correct the trace shown.
audioscope = 63 - audioscope
# Loop count to get the correct position to print the plot.
n = 0
# Set the trace position for each line and......
chardisplay = " "
while n <= audioscope:
# ......add the required spaces until completed then......
chardisplay = chardisplay + " "
n = n + 1
# ......print the plot point using *.
print chardisplay + "*"
# Point to the next character to character in the 8192 string.
# "timebase" can be any value from 1 to 360.
offset = offset + timebase
# Assuming a Ctrl-C arrives here enable the cursor again.
os.system("setterm -cursor off")
main()
# End of DEMO.
# Enjoy finding simple solutions to often very difficult problems.
|
I am working on a kids level seismometer project that is using this method and requires NO dependencies other than a totally standard Python install and standard ASCII.
