Saturday, June 3, 2017

Step by step install of the SDRPlay RSP2 under Ubuntu 16.04 and other debian based linux.


    The SDRPlay RSP2 is an excellent bit of kit.   A highly sensitive SDR with multiple antenna inputs,  input filtering, 10 Mhz bandwidth, and a range from 2Ghz all the way down to 1Khz.   On the windows side, they provide a very nice SDR program called SDR uno.

   Those of us not running windows, however, have a few choices in software.   GQRX is a popular program, built on GNU-radio.  There's a couple of others that escape my mind, but the newcomer, CubucSDR, is starting to stand out.


   After much searching and experimenting,  I have come up with a list of steps that will build and install the needed support frameworks and software to get you up and running with CubicSDR and your SDRPlay.  
CubicSDR manual is here, worth reading through, you might get confused in the software without it.
http://cubicsdr.readthedocs.io/en/latest/index.html

    There are a few software packages that are needed for the SDRPlay to work.   SoapySDR is a framework for talking to several SDR hardware types, Cubic relies on it.   We'll also need the specific soapy module for the SDRPlay, and a few other packages needed to build cubic.

   I have created two scripts that largely automate the installation.   You can download them using the following link:

                    Click to download. Let me know if this link is broken.


And here's a video where I talk about this whole project.


  Now, the instructions.

   You will need to create a folder on your desktop named 'sdrplay' and put these script files there. You will also need to download the driver for linux from the SDRPlay site and also place it in that folder.  Do not install it yet!

   Open a terminal and change into your newly created directory with the command:

cd ~/Desktop/sdrplay

    Now, you can run the first script.  This will install build software from ubuntu's repositories, along with dependencies needed by the packages we will be building.   It will also clone sever github projects, including soapySDR and CubicSDR.

   The script MUST be run as root, so use sudo to execute it:

sudo ./Install_script-pt1.sh

   It will take awhile and will ask you to type 'y' once for the installs.   Once it's completed,  you will need to run the installer from the SDRPlay site.  Again, you need to make sure you run their script as root with sudo.  If it's not executable,  you can run:

sudo chmod +x ./{scriptname}

(where {scriptname} is the name of the downloaded file)

It will show you a license agreement you need to spacebar through and hit 'y' to accept.

   After their script is done, you can run the install script part two, again with sudo:

sudo ./Install_script-pt2.sh

  This one will also take awhile while building CubicSDR.   Once done, you should be all ready to go!   CubicSDR won't automatically be added to any menus, you'll have to do that yourself.  You can also run it from within the terminal by simply typing CubicSDR.    If you had the SDRPlay plugged in during this installation,  unplug it for a few seconds and then plug it back in.  When you run Cubic, it should find the unit and list it for selection.

ADDENDUM:  These scripts also work on the raspberry Pi 3 with the current version of raspian.  Obviously you need to download the raspberry pi version of the hardware driver from the SDRPlay site.  
There's just one extra step to get pulse audio working under raspian.   You need to modify one of the autostart scripts.
In a terminal,  type:

sudo pico /etc/xdg/autostart/pulseaudio.desktop

Scroll down and find the line:

Exec=start-pulseaudio-x11

Change that line to:

Exec=/bin/sh -c "Sleep 5; start-pulseaudio-x11"

Ctrl-o to write the changes,  Ctrl-x to exit.  Now reboot the pi and the pulse audio server will start.  This probably fixes other things that rely on pulse as well.

Have fun!

Kevin,  KB9RLW

The scripts are pasted below.  you can follow through their steps manually with copy/paste into your terminal. (don't forget sudo).  Or you can copy each in it's entirety and paste it into an editor, save it, mark it as executable and then run it.

#/*    script 1 below /*

#! /bin/bash
# This script should install and build all needed stuff for
# using the SDRPlay on Ubuntu 16.04 or later.  It must be
# run as root.
#
# First we install needed dependancies.

apt-get install git build-essential automake cmake g++ swig
apt-get install libgtk2.0-dev libpulse-dev libpython-dev python-numpy.
apt-get install mesa-utils libeglw1-mesa libglw1-mesa-dev
apt-get install freeglut3-dev freeglut3

# Now we'll git the projects we need

git clone https://github.com/jgaeddert/liquid-dsp
wget https://github.com/wxWidgets/wxWidgets/releases/download/v3.1.0/wxWidgets-3.1.0.tar.bz2
tar -xvjf wxWidgets-3.1.0.tar.bz2
git clone https://github.com/pothosware/SoapySDR.git
git clone https://github.com/pothosware/SoapySDRPlay.git
git clone https://github.com/pothosware/SoapyRemote.git
git clone https://github.com/cjcliffe/CubicSDR.git

# Build liquid-dsp

cd liquid-dsp
./bootstrap.sh
./configure --enable-fftoverride
make -j4
make install
ldconfig
cd ..

# Build wxwidgets

cd wxWidgets-3.1.0/
mkdir -p ~/Develop/wxWidgets-staticlib
./autogen.sh
./configure --with-opengl --disable-shared --enable-monolithic --with-libjpeg --with-libtiff --with-libpng --with-zlib --disable-sdltest --enable-unicode --enable-display --enable-propgrid --disable-webkit --disable-webview --disable-webviewwebkit --prefix=`echo ~/Develop/wxWidgets-staticlib` CXXFLAGS="-std=c++0x" --with-libiconv=/usr
make -j4
make install
cd ..

echo "."
echo "First part of installation done.   Now run the SDRPlay file you"
echo "downloaded from their site.  Be sure to use sudo to run it!"

#/* end of script 1 /*


#/* script 2 below /*

#! /bin/bash
# This script should install and build all needed stuff for
# using the SDRPlay on Ubuntu 16.04 or later.  It must be
# run as root.
#
# This is part two.
# Here we build SoapySDR

cd SoapySDR
mkdir build
cd build
cmake ..
make -j4
make install
ldconfig
cd ..
cd ..

# Now we build the SDRPlay module for Soapy

cd SoapySDRPlay
mkdir build
cd build
cmake ..
make
make install
cd ..
cd ..

# And we build SoapyRemote

cd SoapyRemote
mkdir build
cd build
cmake ..
make
make install
cd ..
cd ..

# And finally,  we build Cubic.  This takes awhile!

cd CubicSDR
mkdir build
cd build
cmake ../ -DCMAKE_BUILD_TYPE=Release -DwxWidgets_CONFIG_EXECUTABLE=~/Develop/wxWidgets-staticlib/bin/wx-config
make
make install
cd ..
cd ..
rm -R ~/Develop

# now we change permissions on these root-owned folders so the user can
# delete them at their leisure.

chmod -R 0777 ./*

# And we're done.   Cubic should work with the SDRPlay.  The user can
# run it from the terminal with CubicSDR or add this command to a menu.

#/* end of script 2 /*

Monday, May 1, 2017

The Arduino based Super Simple Keyer

     I decided to build my own keyer.  I needed a new Arduino project and this seemed like the perfect one.    I had a few ideas for the design.

     I wanted a keyer that would take multiple inputs,  paddles, straight key, and computer keyboard.  The idea being you can send however you like, without needing to change around cables, just send.

     There are many arduino morse projects around already.  I suppose I could have just downloaded an existing one, dropped it in and ran with it.  But I wanted to tackle the challenge of coding it myself.



     Once I'd sorted the hardware out,  I started to work on the software.   It turned out to be a bigger challenge than I'd expected!   It's tricky, the timing of reading the paddles and keying.   I came up with an interesting solution to timing when it comes to keying the rig.

     You see, the main loop in the arduino sketch can vary in how fast it executes, based on how much work it has to do.   My solution was to use a timer in the chip and schedule an interrupt.

     All processors have timers for this.   They run at a set speed and can interrupt the processor, forcing it to execute a small routine at precise intervals.  This is useful in robotics, for example, like in a flying drone.  You would need adjustments to the motor speeds to be occurring fast and regularly.

    So, in my keyer,  there is an interrupt that is running a keying routine once every millisecond.  That's 1000 times per second,  precisely.   That allows me to control the timing of the keying exactly and produce clean, consistent Morse out to the radio.    This routing watches a buffer that I load with events using the characters period,  dash, and comma.    Period and dash are obviously the Morse elements, and the comma is a delay equivalent to a dot.

    So to send an 'A' for example,  you'd load the event buffer with  .,-,   dot comma dash comma.   The interrupt routine would immediately key the transmitter with cleanly spaced precise Morse.

    The hardware is extremely simple.  The schematic is below.   The pins chosen are arbitrary and can be changed to suit your build if needed.  They are referenced in the first few lines of the code and you change those to reflect the pins you use.   The keying is handled by a simple transistor switch.  You could use an opto-isolator if you wish,  but I've had no trouble keying modern rigs this way.





   The software is below.  Simply copy and paste it into the Arduino IDE to upload it to your board.  Upon startup it will briefly key the radio for a fraction of a second and then be ready to accept input.  I wired an additional input jack for a straight key.  That was simply parallel to the keying output and done for convenience.

    For keyboard input, the code monitors the serial input.  When the Arduino is powered by a USB connection to your computer, it will create a serial port.   Simply run a terminal program and connect it to that port to allow you to send keyboard CW.  You want to set your terminal program to 9600 baud, no parity, 1 stop bit and 8 data bits.  Type to send at the current speed.  Simple.

   The code is up to version 1.4.   Paddle routines have been heavily worked on,  2 memories have been added.    shft-alt-1 to load memory one,  alt-1 to send memory one.  Same for memory 2,  shft-alt-2 and alt-2.

Code pasted below:

/*

  Super Simple Keyer Ver 1.4  Arduino based keyer
  Written Apr. 30, 2017 by Kevin Loughin, KB9RLW

Ver 1
  Initial release, keyer working ok, not iambic

Ver 1.2
  First iambic code, dependent on timing, not perfect

Ver 1.3
  Rewrite of keyer logic, iambic and dot dash buffering working!

Ver 1.4
  Tweaked paddles a bit.  Added 2 memories.  shft-alt-1 to set mem 1, shft-alt-2 to set memory 2
  alt-1 to send memory 1, alt-2 to send memory 2.
  Tweaked character spacing for keyboard decode. Added BT using the minus sign.

*/

//  Pins we're going to use.  Change as needed.
const int wpmraw = A7;  //Pot sense for speed
const int dotin = 4;  //dot sense pin
const int dashin = 2; //dash sense pin
const int keyout = 13; //keying output

// declaring variables we'll use in program

int delayval = 150;  //delay between elements in milliseconds
String event = "";  //event contains the elements currently being sent, .=dot -=dash ,=space
String memory1 = ""; //user memory 1
String memory2 = ""; //user memory 2
String membuff; // buffer for memory sending
int dotlen = 150;  //current dot length in milliseconds
int dashlen = (dotlen * 3);  //dash length in milliseconds
int active = 0; //keying handler flag
int delaycount = 0; // delay counter in interrup handler
int dotstate = 1; // dot paddle input pins reading
int dotread = 0;
int dashstate = 1; //dash paddle input pins reading
int lastdotstate = 1;
int lastdashstate = 1;
int dashread;
int lastdashdebounce;
int lastdotdebounce;
int eventbuffer = 0;  // event buffering
int dashhalf;
int lastchar = 1;
int c;
int dotbuffer;
int dashbuffer;
int dashdelay;
int dotdelay;
int flag;

void setup() {
  // Turn off keying pin right away

  pinMode (keyout, OUTPUT);
  digitalWrite(keyout, LOW);


  // setup input pins
  pinMode (dotin, INPUT);
  pinMode (dashin, INPUT);
  digitalWrite(dotin, HIGH);
  digitalWrite(dashin, HIGH);
  Serial.begin(9600);

  //  setup the interrupt
    OCR0A = 0xAF;
  TIMSK0 |= _BV(OCIE0A);
}


//  interrupt handler
SIGNAL(TIMER0_COMPA_vect)
{
 if (  event.length() > 0  ) //do we have anything to do?
 {
   if ( !active ) //are we not currently sending?
   {
     if ( event.charAt(0) == '.')  //do we need to send a dot?
     {
      digitalWrite(keyout, HIGH); //key on
      delaycount = dotlen;
      active = 1;
      lastchar = 1;
     }
     if ( event.charAt(0) == '-' ) //do we need to send a dash?
     {
      digitalWrite(keyout, HIGH); //key on
      delaycount = dashlen;
      active = 1;
      lastchar = 2;
   
     }
     if ( event.charAt(0) == ',' )  //do we need to delay between elements?
     {
       delaycount = dotlen;
      digitalWrite(keyout, LOW); //key off
      active = 1;
      }

     }
   
    }
    if ( active ) // we're already active, count and reset when done
     {
       delaycount--;
        if ( !delaycount )  //are we done with this element?
        {
          active = 0;
          digitalWrite(keyout, LOW); //just make sure the key is off
          event.remove(0, 1);
        }
      }
  }


void loop()
{
  // read the speed and set timing

dotlen = ( 200 - (.146 * analogRead(wpmraw)) );
dashlen = ( 3 * dotlen );

//  Read paddle inputs

          // read the dash pin
  dashread = digitalRead(dashin);
   if ( dashread != lastdashstate )
      lastdashdebounce = millis();
   
    if ( (millis() - lastdashdebounce) > 40 )
    {
      if ( dashread != dashstate )
        dashstate = dashread;
    }
    lastdashstate = dashread;
 
  // read the dot pin
  dotread = digitalRead(dotin);
 if (dotread != lastdotstate)
      lastdotdebounce = millis();
   
    if ((millis() - lastdotdebounce) > 40)
    {
      if (dotread != dotstate)
        dotstate = dotread;
    }
    lastdotstate = dotread;


// Keyer logic

while (!dotstate || !dashstate )  //   if paddles pressed, do
  {
    if ( event.length() < 3 )  // don't bother unless there's no more than 1 chars in buffer
    {

      if ( !dotstate && !dashstate ) // both paddles?
      {
        if ( lastchar == 1 && ( delaycount < dashlen ))
        {
          event = String(event + "-,");
          lastchar = 2;break;
        }
        if ( lastchar == 2 && ( delaycount < dashlen ))
        {
          event = String(event + ".,");
          lastchar = 1;break;
        }
      }

      if ( !dotstate && dashstate )  // only dot paddle
      {
        if ( lastchar == 1 && ( delaycount < dashlen) && event.length() < 1)
        {
          event = String(event + ".,");break;
        }
        if ( lastchar == 2 && event.length() < 3)
        {
          event = String(event + ".,");break;
        }
      }

      if ( dotstate && !dashstate )  // only dash paddle
      {
        if ( lastchar == 1 && (delaycount < dotlen))
        {
          event = String(event + "-,");break;
        }
        if ( lastchar == 2 && (delaycount < (dotlen * 2)) & event.length() < 2)
        {
          event = String(event + "-,");break;
        }
      }
    }
break;
  }
delay(12);

//  Keyboard routines

while(Serial.available())
 {
  c = Serial.read();
  Serial.write(c);
  // check for special keys
  if ( c == 27 ) // alt key pressed
    {
      flag = 1;
      c = Serial.read();
    }
  if ( flag && c == 33 ) // shft-alt-1, memory 1 define
    {
    loadmemory(1);
    flag = 0;
    c = 0;
    }
  if ( flag && c == 64 ) // shift-alt-2, memory 2 define
    {
      loadmemory(2);
      flag = 0;
      c = 0;
    }
  if ( flag && c == 49 ) // alt 1, send memory 1
    {
      sendmemory(1);
      flag = 0;
      c = 0;
    }
  if ( flag && c == 50 ) // alt 2, send memory 2
    {
      sendmemory(2);
      flag = 0;
      c = 0;
    }
 
  decoder(c);  // call the keyboard decoder to load this event
 }
}

void loadmemory(int num) // interact with user to load a memory
{
  String inData;
  char received;
  Serial.println( "." );
  Serial.print( "Enter the contents for memory " );
  Serial.println( num );
  Serial.println();

    while ( received != 13 )
    {
      if (Serial.available())
      {
        received = Serial.read();
        Serial.write(received);
        inData += received;
      }
    }
  if ( num == 1 ) // loading memory1
    {
      memory1 = inData;
    }
  if ( num == 2 ) // loading memory2
    {
      memory2 = inData;
    }
  Serial.println();
  Serial.print( "Memory " );
  Serial.print( num );
  Serial.println( " loaded with" );
  Serial.println( inData );
  inData == "";
}

void sendmemory(int num) // send memory number num
{
  if ( num == 1 )
    membuff = memory1;
  else
    membuff = memory2;
  Serial.println( "." );
  Serial.println( membuff );
  for(int leng = membuff.length(); leng > 0; leng--)
    {
      decoder(membuff.charAt( membuff.length() - leng ));
    }
}
void decoder(int in) // function to decode char for sending and load send buffer
{
       switch(in)
  {
      case ' ' : event = String(event + ",,"); break;
      case 'a' : event = String(event + ".,-,,,"); break;
      case 'b' : event = String(event + "-,.,.,.,,,"); break;
      case 'c' : event = String(event + "-,.,-,.,,,"); break;
      case 'd' : event = String(event + "-,.,.,,,"); break;
      case 'e' : event = String(event + ".,,,"); break;
      case 'f' : event = String(event + ".,.,-,.,,,"); break;
      case 'g' : event = String(event + "-,-,.,,,"); break;
      case 'h' : event = String(event + ".,.,.,.,,,"); break;
      case 'i' : event = String(event + ".,.,,,"); break;
      case 'j' : event = String(event + ".,-,-,-,,,"); break;
      case 'k' : event = String(event + "-,.,-,,,"); break;
      case 'l' : event = String(event + ".,-,.,.,,,"); break;
      case 'm' : event = String(event + "-,-,,,"); break;
      case 'n' : event = String(event + "-,.,,,"); break;
      case 'o' : event = String(event + "-,-,-,,,"); break;
      case 'p' : event = String(event + ".,-,-,.,,,"); break;
      case 'q' : event = String(event + "-,-,.,-,,,"); break;
      case 'r' : event = String(event + ".,-,.,,,"); break;
      case 's' : event = String(event + ".,.,.,,,"); break;
      case 't' : event = String(event + "-,,,"); break;
      case 'u' : event = String(event + ".,.,-,,,"); break;
      case 'v' : event = String(event + ".,.,.,-,,,"); break;
      case 'w' : event = String(event + ".,-,-,,,"); break;
      case 'x' : event = String(event + "-,.,.,-,,,"); break;
      case 'y' : event = String(event + "-,.,-,-,,,"); break;
      case 'z' : event = String(event + "-,-,.,.,,,"); break;
      case 'A' : event = String(event + ".,-,,,"); break;
      case 'B' : event = String(event + "-,.,.,.,,,"); break;
      case 'C' : event = String(event + "-,.,-,.,,,"); break;
      case 'D' : event = String(event + "-,.,.,,,"); break;
      case 'E' : event = String(event + ".,,,"); break;
      case 'F' : event = String(event + ".,.,-,.,,,"); break;
      case 'G' : event = String(event + "-,-,.,,,"); break;
      case 'H' : event = String(event + ".,.,.,.,,,"); break;
      case 'I' : event = String(event + ".,.,,,"); break;
      case 'J' : event = String(event + ".,-,-,-,,,"); break;
      case 'K' : event = String(event + "-,.,-,,,"); break;
      case 'L' : event = String(event + ".,-,.,.,,,"); break;
      case 'M' : event = String(event + "-,-,,,"); break;
      case 'N' : event = String(event + "-,.,,,"); break;
      case 'O' : event = String(event + "-,-,-,,,"); break;
      case 'P' : event = String(event + ".,-,-,.,,,"); break;
      case 'Q' : event = String(event + "-,.,-,-,,,"); break;
      case 'R' : event = String(event + ".,-,.,,,"); break;
      case 'S' : event = String(event + ".,.,.,,,"); break;
      case 'T' : event = String(event + "-,,,"); break;
      case 'U' : event = String(event + ".,.,-,,,"); break;
      case 'V' : event = String(event + ".,.,.,-,,,"); break;
      case 'W' : event = String(event + ".,-,-,,,"); break;
      case 'X' : event = String(event + "-,.,.,-,,,"); break;
      case 'Y' : event = String(event + "-,.,-,-,,,"); break;
      case 'Z' : event = String(event + "-,-,.,.,,,"); break;
      case '0' : event = String(event + "-,-,-,-,-,,,"); break;
      case '1' : event = String(event + ".,-,-,-,-,,,"); break;
      case '2' : event = String(event + ".,.,-,-,-,,,"); break;
      case '3' : event = String(event + ".,.,.,-,-,,,"); break;
      case '4' : event = String(event + ".,.,.,.,-,,,"); break;
      case '5' : event = String(event + ".,.,.,.,.,,,"); break;
      case '6' : event = String(event + "-,.,.,.,.,,,"); break;
      case '7' : event = String(event + "-,-,.,.,.,,,"); break;
      case '8' : event = String(event + "-,-,-,.,.,,,"); break;
      case '9' : event = String(event + "-,-,-,-,.,,,"); break;
      case '.' : event = String(event + ".,-,.,-,.,-,,,"); break;
      case '-' : event = String(event + "-,.,.,.,-,,,"); break;
      case '/' : event = String(event + "-,.,.,-,.,,,"); break;
  }
}



Thursday, January 5, 2017

Giving a voice to someone who's lost the ability to speak.

As they say, necessity can be the mother of invention.  

    In December of 2016 I lost my best friend of over 30 years.   He had suffered a major stroke and was in a coma for just over a week.   He came out of the coma, but could not speak, and could only move his hands a bit and feet.   He was in there, he could communicate by squeezing his hand, but that was all.

   I immediately dreamed up a way of giving him a voice back.   This project is the result.

   Unfortunately,  my friend had a second stroke and didn't survive.   I decided to go ahead with the project though,  I'm hopeful that it can help someone out there somewhere.   I call it,  The CW Voice Box.

   Morse code is one of the oldest ways of sending letters with a simple on off signal.   Short patterns of long and short tones.  An ideal way for someone who can only squeeze, bite, or blink to be able to spell out words.    This project is exactly that.  You key in Morse code, it speaks the letters.   A voice for the voiceless.

   There are other devices out there to accomplish this, it's not a new idea.   However,  those devices are expensive!   With the technology we have today,  you can build my voice box for around 45 bucks.    Maybe a little more if you want a fancy case.

The parts list:

     Computer:    Raspberry Pi zero.     I recommend the starter pack over at Adafruit: $24.95
Adafruit Raspi budget pack.

     USB sound card:     There's many available on Amazon,  here's one that works:   $5.99
USB sound card

     8 Gig micro SD card.    $7

     5 volt audio amp:   There's lots of these to choose from,  one example below:  $7
Audio amp

     A speaker of some type.   I'll leave that up to you.

     You'll also need some bits of wire, some kind of a case, and an input device.    Regarding input devices....    What you need will depend entirely upon the capabilities of the person you are trying to help.    There are commercial squeeze bulb switches,   bite switches,   and other devices available.   I'll leave the input method up to you.    The only requirement is that the person needs to be able to input long and short signals in a pattern.

     Putting it all together:

     I've already done the hard work on the software.   I have built a Raspian image for your Pi zero that will boot directly into the morse decoding speech software.   You can download the image from the link below.

Custom Raspian image zip file.

(Many thanks to bitchen.com for offering to host the file.)

    Write this image to the micro SD card and put it in the pi.

     The starter pack will come with a 2Amp power supply,  plug that into the pi.
      Using the USB adapter, you can plug in the usb audio dongle to the second micro usb port on the pi.
      Your input device will need to connect to GPIO pin 7 on the pi, and also to ground.

      The audio amp will need 5 volts.   You can tap that from pin 2 on the pi.  It also needs a ground connection.

      Audio from the USB dongle goes to the input of the amp, and obviously the speaker will connect to it's output.

      When you plug in the power supply,  the pi should boot and within about 20 seconds it will speak the word  "Ready".    you're good to go.   Simply start keying in Morse and it will speak each letter, number, and some punctuation.

     It will reliably decode Morse from around 5 words per minute speed, up to about 10 words per minute speed.   To get an idea of the speed,  watch the demo towards the end of my video about the project,  linked below.


Full video.


    The software is built upon a great educational python program on the raspberry pi site.   I modified the software to make it compatibly with python3,  re-ordered it's lookup table for speed, and integrated espeak speech synthesis.    The raspian image was further modified to fix espeak errors with alsa, and set to boot to command line and run the decoder on boot.

    The original morse code decoder project on the raspberry site is linked below.

Morse decode I built upon.

My modified source code follows:

----------------------------------------------------

#!/usr/bin/python3
# modified code based on a tutorial project on the raspberry pi organizations web site.
# original project can be found here:
# https://www.raspberrypi.org/learning/morse-code-virtual-radio/worksheet/
import pygame
import time
from RPi import GPIO
import _thread
from array import array
from pygame.locals import *
from morse_lookup import *
from espeak import espeak

pygame.mixer.pre_init(44100, -16, 1, 1024)
pygame.init()

class ToneSound(pygame.mixer.Sound):
    def __init__(self, frequency, volume):
        self.frequency = frequency
        pygame.mixer.Sound.__init__(self, self.build_samples())
        self.set_volume(volume)

    def build_samples(self):
        period = int(round(pygame.mixer.get_init()[0] / self.frequency))
        samples = array("h", [0] * period)
        amplitude = 2 ** (abs(pygame.mixer.get_init()[1]) - 1) - 1
        for time in range(period):
            if time < period / 2:
                samples[time] = amplitude
            else:
                samples[time] = -amplitude
        return samples

def wait_for_keydown(pin):
    while GPIO.input(pin):
        time.sleep(0.01)

def wait_for_keyup(pin):
    while not GPIO.input(pin):
        time.sleep(0.01)

def decoder_thread():
    global key_up_time
    global buffer
    new_word = False
    while True:
        time.sleep(.01)
        key_up_length = time.time() - key_up_time
        if len(buffer) > 0 and key_up_length >= 1.5:
            new_word = True
            bit_string = "".join(buffer)
            try_decode(bit_string)
            del buffer[:]
        elif new_word and key_up_length >= 4.5:
            new_word = False
            sys.stdout.write(" ")
            sys.stdout.flush()

tone_obj = ToneSound(frequency = 800, volume = .03)

pin = 7
GPIO.setmode(GPIO.BOARD)
GPIO.setup(pin, GPIO.IN, pull_up_down=GPIO.PUD_UP)

DOT = "."
DASH = "-"

key_down_time = 0
key_down_length = 0
key_up_time = 0
buffer = []

_thread.start_new_thread(decoder_thread, ())

print("Ready")
espeak.synth("Ready")

while True:
    wait_for_keydown(pin)
    key_down_time = time.time() #record the time when the key went down
    tone_obj.play(-1) #the -1 means to loop the sound
    wait_for_keyup(pin)
    key_up_time = time.time() #record the time when the key was released
    key_down_length = key_up_time - key_down_time #get the length of time it was held down for
    tone_obj.stop()
    buffer.append(DASH if key_down_length > 0.3 else DOT)


------------------------------

And the morse_lookup.py source as well.

---------------------------------

#!/usr/bin/python
import sys
from espeak import espeak

morse_code_lookup = {
    ".":    "E",
    "-":    "T",
    ".-":    "A",
    "---":    "O",
    "..":    "I",
    "-.":    "N",
    "...":    "S",
    "....":    "H",
    ".-.":    "R",
    "-..":    "D",
    ".-..":    "L",
    "-.-.":    "C",
    "..-":    "U",
    "--":    "M",
    ".--":    "W",
    "..-.":    "F",
    "--.":    "G",
    "-.--":    "Y",
    ".--.":    "P",
    "-...":    "B",
    "...-":    "V",
    "-.-":    "K",
    ".---":    "J",
    "-..-":    "X",
    "--.-":    "Q",
    "--..":    "Ze",
    ".----":    "1",
    "..---":    "2",
    "...--":    "3",
    "....-":    "4",
    ".....":    "5",
    "-....":    "6",
    "--...":    "7",
    "---..":    "8",
    "----.":    "9",
    "-----":    "0",
    "..--..":    "question mark",
    ".-.-.-":    "period"
}

def try_decode(bit_string):
    if bit_string in morse_code_lookup.keys():
#        sys.stdout.write(morse_code_lookup[bit_string])
        espeak.synth(morse_code_lookup[bit_string])
#        sys.stdout.flush()

------------------------------------
 


    Please share,  I hope this project will get out there and find someone who can use it.    I would be absolutely thrilled to hear back from someone who was able to give a voice back to somebody who'd lost theirs.

    Thanks,

Kevin.