Another Python 3.x.x Vertical Bargraph Generator...

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Another Python 3.x.x Vertical Bargraph Generator...

Postby Bazza » Sat Apr 23, 2011 8:00 pm

Hi all...

Similar to the horizontal one in this forum but in the vertical plane this time.

Given away as usual and looks just like a(n) LED "VU" display uaed on
audio gear.

Enjoy finding simple solutions to often very difficult problems...

This needs only a default Python 3.x.x install inside Linux(/*IX?).

Code: Select all
# A DEMO 4 bit slow analogue bargraph generator in colour for STANDARD Python 3.x and Linux...
# This is a vertical version of the horizontal one also given away by myself.
# It is written so that anyone can understand how it works.
# (Original copyright, (C)2011, B.Walker, G0LCU.)
# Issued initially to LXF as Public Domain, and to other sites later.
# Saved as wherever you like.
# This DEMO goes from safe green, to warning amber, to danger red, with a crirical
# error beep above 14 on the vertical scale...
# It is a slow "AT A GLANCE" display for quick assessments, not for accuracy.
# Two system commands are required, "clear" and "setterm", for this to work.
# I assume that these are available on all recent and current Linux distros.
# The device /dev/audio is used so this must be free also.
# It is useful for quick "AT A GLANCE" readings from say an 8 bit ADC used as a simple
# voltmeter, ammeter, etc. Getting a digital readout is SO simple I left it out this time...
# To run use the following from inside a Python prompt...
# exec(open("/full/path/to/code/").read())
# This looks like an "LED" style "VU" display...

# Add the required imports for this DEMO.
import os
import random
import time

# Just for this DEMO set up variables as global...
global count
global row
global blank
global greenlines
global yellowlines
global redlines
global waveform
global char

# Startup variable values here.
blank="(C)2011, B.Walker, G0LCU."
# This is a squarewave binary for the critical error beep.

def main():
   # Disable the cursor as it looks much nicer... ;o)
   os.system("setterm -cursor off")

   while 1:
      # Run continuously and use Ctrl-C to STOP!
      blank="\033[0m                                 "
      # Generate a byte value as though grabbed from a serial, parallel or USB port.
      # Now divide by 16 to simulate a 4 bit value.
      # Although this should never occur, don't allow any error.
      if row>=15: row=15
      if row<=0: row=0

      # Do a full, clean, clear screen and start looping.
      os.system("clear"),chr(13),"  ",chr(13),
      print("\033[0mFour Bit Level Vertical Analogue Bar Graph Display...")
      print("Original copyright, (C)2011, B.Walker, G0LCU.")
      print("Issued to LXF on 24-04-2011 as Public Domain.")
      print(blank+"\033[1;31m15 __ ")
      redlines=blank+"\033[1;31m14 __ "
      if row>=15: redlines=redlines+char

      redlines=blank+"\033[1;31m13 __ "
      if row>=14: redlines=redlines+char

      yellowlines=blank+"\033[1;33m12 __ "
      if row>=13: yellowlines=yellowlines+char

      yellowlines=blank+"\033[1;33m11 __ "
      if row>=12: yellowlines=yellowlines+char

      yellowlines=blank+"\033[1;33m10 __ "
      if row>=11: yellowlines=yellowlines+char

      greenlines=blank+"\033[1;32m 9 __ "
      if row>=10: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 8 __ "
      if row>=9: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 7 __ "
      if row>=8: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 6 __ "
      if row>=7: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 5 __ "
      if row>=6: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 4 __ "
      if row>=5: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 3 __ "
      if row>=4: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 2 __ "
      if row>=3: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 1 __ "
      if row>=2: greenlines=greenlines+char

      greenlines=blank+"\033[1;32m 0 __ "
      if row>=1: greenlines=greenlines+char
      if row==0: greenlines=greenlines+"__"
      # Reset to default colours...
      print("\033[0mPress Ctrl-C to stop...")

      if row<=14: time.sleep(1)
      if row==15:
         # Set audio timing to zero, "0".
         # Open up the audio device to write to.
         # This could be /dev/dsp also...
         audio=open("/dev/audio", "wb")
         # A "count" value of 1 = 1mS, so 1000 = 1S.
         while count<=1000:
            # Send 8 bytes of data to the audio device 1000 times.
            # This is VERY close to 1KHz and squarewave.
         # Close the audio device access.
   # Enable the cursor again if it ever gets here... ;oO
   os.system("setterm -cursor on")

# End of DEMO...
# Enjoy finding simple solutions to often very difficult questions.


Bazza, G0LCU...

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