I built something like this for about 10% of what MFJ gets for theirs. I wanted something to “have my back” while I operate CW in the field, in case I miss any characters. It also boosts my confidence to look up at it and see that what I copied is close to what it copied.
http://www.mfjenterprises.com/Product.php?productid=mfj-461
Zero Beat Kit
http://home.windstream.net/johnshan/cw_ss_zerobeat.html
R1 – value depends on DC voltage available. For 13.5V use a 470-ohm 1/4w, for 9V use a 180-ohm 1/4w.
Zener Diode – I used a 5.1 volt diode as that’s what I had on hand, works great. Also allows me to power an Arduino mini and the display.
R2 – 10K-ohm or 20K-ohm potentiometer
R3 – 1K-ohm resistor
C1 – 1.0 Mfd
C2,C4,C5,C6 – 0.1 Mfd (marked 104)
C3 – 1 Mfd is what I used but could be 0.47 or even up to 10 Mfd
What you see above are the parts changes I made, so that’s as I have built it. I have plenty more parts to build about 10 more of these.
This thing can be useful as a stand alone. It pretty much does what the blue LED on the 857 does. I can see it being very handy with the 49er. So it can be built as a stand alone or built into a radio or whatever.
But if you run another wire off of Pin 8, the output of the IC you can then run that right into the digital input of an Arduino. The LED and it’s resistor already setup an appropriate pull-up voltage. So it still functions as before, you don’t lose anything, but now it is the detector for the CW decoder.
Arduino
The code is small enough to run on pretty much any Arduino. You could add more to the code if you wanted, I’ve seen some of these where they build them as keyers for sending or to send code as trainers. I just wanted to keep it simple.
The code I started with suggested a 4 line, 20 column display. So I ordered one and they are cheap, not much more than the 2 line, 16 character displays. I ordered my with the little I2C backpack module on it, just like the 2 line displays we got with the 49er kit. My thinking was that it takes fewer wires to connect and it was easy enough.
In hindsight I wish I hadn’t. The code you see here works but it still isn’t 100%. I had to modify it to use the LiquidCrystal_I2C library and it turns out there are some differences from LiquidCrystal. I’m not sure what all those differences are yet, still learning that. But I went a while with not being able to get anything at all on the display. It works now, works just fine, but I am sure more could be done with it.
So if you want to build one I would recommend that you buy a display without the I2C backpack and just any small, cheap Arduino.
Decoding
I have used my cell phone with a trainer app to send code into the decoder and it works about 98-99% I have also hooked it up to my PC and used FLdigi to send it code with the same results. It seems happy with speeds between about 13 and 31 WPM and it can quickly adapt to speed changes on the fly. I also used a WebSDR and fed it live signals from 40 and 80 meters and it did really well.
I haven’t tried it with a radio yet. The input to the decoder board might want another pot on it for input level adjustment. It might also want an amp on the input too, maybe on the 49er, if the input is low. Easy enough to do.
If you want you could add a microphone and amp to give you the capability to acoustically couple to the receiver. If you didn’t want to recycle something you could buy an electret mic for about $0.75 shipped from China and I have a zillion 2N2222 and 2N3904 transistors to make the amp.
/*********************************************************************** WB7FHC's Morse Code Decoder v. 1.1 (c) 2014, Budd Churchward - WB7FHC This is an Open Source Project http://opensource.org/licenses/MIT Search YouTube for 'WB7FHC' to see several videos of this project as it was developed. MIT license, all text above must be included in any redistribution ********************************************************************** This project makes use a custom built tone decoder module using the LM567C microchip. Details of this module will eventually be posted on line. This module allows you to tune to the frequency of a specific tone while ignoring noice and other tones of different frequencies The program will automatically adjust to the speed of code that is being sent. The first few characters may come out wrong while it homes in on the speed. If you are not seeing solid copy, press the restart button on your Arduino. You can try adjusting the tone decoder. Lowering the volume of the incoming CW can also help. If the tone decoder is not centered on the frequency of the incomming signal, you may have to fine tune the module as you lower the volume. The software tracks the speed of the sender's dahs to make its adjustments. The more dahs you send at the beginning the sooner it locks into solid copy. After a reset, the following text is very difficult to lock in on: 'SHE IS HIS SISTER' because there are only two dahs in the whole phrase and they come near the end. However, if you reset and then send 'CALL ME WOODY' it will match your speed quite quickly. This project is built around the 20x4 LCD display. The sketch includes funtions for word wrap and scrolling. If a word extends beyond the 20 column line, it will drop down to the next line. When the bottom line is filled, all lines will scroll up one row and new text will continue to appear at the bottom. This version makes use of the 4 digit parallel method of driving the display. If you are planning on using a 16x2 you will want to make some changes. Frankly, I don't think scrolling makes sense with only two lines. Sometimes long words or missed spaces will result in only two words left on your display. If you don't have a 20x4 (they're really only a few bucks more) you might want to leave out the word wrap and scrolling. Hook up your LCD panel to the Arduino using these pins: LCD pin 1 to GND LCD pin 2 to +5V LCD pin 4 to D7 LCD pin 6 to D6 LCD pin 11 to D5 LCD pin 12 to D4 LCD pin 13 to D3 LCD pin 14 to D2 LCD pin 15 to +5V LCD pin 16 to GND Data from pin 8 of the LM567C will be fed to D8 on the Arduino When this pin is HIGH there is no tone detected. When this pin is LOW a tone of the set frequency has been detected. *********************************************************************/ /********************************/ // include the library code #include <Wire.h> #include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x3F,20,4); // set the LCD address to 0x27 for a 16 chars and 2 line display /*********************************************************/ //#include <LiquidCrystal.h> // initialize the library with the numbers of the interface pins //LiquidCrystal lcd(7, 6, 5, 4, 3, 2); int audioPin = 8; // we read data from the tone detector module here int audio = 1; // will store the value we read on this pin int LCDline = 1; // keeps track of which line we're printing on int lineEnd = 21; // One more than number of characters across display int letterCount = 0; // keeps track of how may characters were printed on the line int lastWordCount = 0; // keeps track of how may characters are in the current word int lastSpace = 0; // keeps track of the location of the last 'space' // The next line stores the text that we are currently printing on a line, // The charcters in the current word, // Our top line of text, // Our second line of text, // and our third line of text // For a 20x4 display these are all 20 characters long char currentLine[] = "12345678901234567890"; char lastWord[] = " "; char line1[] = " "; char line2[] = " "; char line3[] = " "; boolean ditOrDah = true; // We have either a full dit or a full dah int dit = 10; // We start by defining a dit as 10 milliseconds // The following values will auto adjust to the sender's speed int averageDah = 240; // A dah should be 3 times as long as a dit int averageWordGap = averageDah; // will auto adjust long fullWait = 6000; // The time between letters long waitWait = 6000; // The time between dits and dahs long newWord = 0; // The time between words boolean characterDone = true; // A full character has been sent int downTime = 0; // How long the tone was on in milliseconds int upTime = 0; // How long the tone was off in milliseconds int myBounce = 2; // Used as a short delay between key up and down long startDownTime = 0; // Arduino's internal timer when tone first comes on long startUpTime = 0; // Arduino's internal timer when tone first goes off long lastDahTime = 0; // Length of last dah in milliseconds long lastDitTime = 0; // Length oflast dit in milliseconds long averageDahTime = 0; // Sloppy Average of length of dahs boolean justDid = true; // Makes sure we only print one space during long gaps int myNum = 0; // We will turn dits and dahs into a binary number stored here ///////////////////////////////////////////////////////////////////////////////// // Now here is the 'Secret Sauce' // The Morse Code is embedded into the binary version of the numbers from 2 - 63 // The place a letter appears here matches myNum that we parsed out of the code // #'s are miscopied characters char mySet[] ="##TEMNAIOGKDWRUS##QZYCXBJP#L#FVH09#8###7#####/-61#######2###3#45"; char lcdGuy = ' '; // We will store the actual character decoded here ///////////////////////////////////////////////////////////////////////////////// void setup() { lcd.init(); //initialize the lcd lcd.backlight(); //open the backlight lcd.setCursor ( 0, 0 ); // go to the top left corner //lcd.print(" Hello,world! "); // write this string on the top row lcd.print(" N7JCT "); //lcd.print("12345678901234567890"); lcd.setCursor ( 0, 1 ); // go to the 2nd row lcd.print(" Handcrafted "); // pad string with spaces for centering lcd.setCursor ( 0, 2 ); // go to the third row lcd.print(" With A Smile "); // pad with spaces for centering lcd.setCursor ( 0, 3 ); // go to the fourth row lcd.print(" And A Beer "); delay(2000); lcd.clear(); pinMode(audioPin, INPUT); pinMode(13,OUTPUT); // We're going to blink Arduino's onboard LED lcd.begin(20, 4); // Cuzz we have a 20x4 display lcd.clear(); // Get rid of any garbage that might appear on startup delay(2000); lcd.print("CW DECODER A.1"); lcd.setCursor(0,1); } void loop() { audio = digitalRead(audioPin); // What is the tone decoder doing? if (!audio) keyIsDown(); // LOW, or 0, means tone is being decoded if (audio) keyIsUp(); // HIGH, or 1, means no tone is there } void keyIsDown() { // The decoder is detecting our tone // The LEDs on the decoder and Arduino will blink on in unison digitalWrite(13,1); // turn on Arduino's LED if (startUpTime>0){ // We only need to do once, when the key first goes down startUpTime=0; // clear the 'Key Up' timer } // If we haven't already started our timer, do it now if (startDownTime == 0){ startDownTime = millis(); // get Arduino's current clock time } characterDone=false; // we're still building a character ditOrDah=false; // the key is still down we're not done with the tone delay(myBounce); // Take a short breath here if (myNum == 0) { // myNum will equal zero at the beginning of a character myNum = 1; // This is our start bit - it only does this once per letter } } void keyIsUp() { // The decoder does not detect our tone // The LEDs on the decoder and Arduino will blink off in unison digitalWrite(13,0); // turn off Arduino's LED // If we haven't already started our timer, do it now if (startUpTime == 0){startUpTime = millis();} // Find out how long we've gone with no tone // If it is twice as long as a dah print a space upTime = millis() - startUpTime; if (upTime<10)return; if (upTime > (averageDah*2)) { printSpace(); } // Only do this once after the key goes up if (startDownTime > 0){ downTime = millis() - startDownTime; // how long was the tone on? startDownTime=0; // clear the 'Key Down' timer } if (!ditOrDah) { // We don't know if it was a dit or a dah yet shiftBits(); // let's go find out! And do our Magic with the bits } // If we are still building a character ... if (!characterDone) { // Are we done yet? if (upTime > dit) { // BINGO! we're done with this one printCharacter(); // Go figure out what character it was and print it characterDone=true; // We got him, we're done here myNum=0; // This sets us up for getting the next start bit } downTime=0; // Reset our keyDown counter } } void shiftBits() { // we know we've got a dit or a dah, let's find out which // then we will shift the bits in myNum and then add 1 or not add 1 if (downTime < dit / 3) return; // ignore my keybounce myNum = myNum << 1; // shift bits left ditOrDah = true; // we will know which one in two lines // If it is a dit we add 1. If it is a dah we do nothing! if (downTime < dit) { myNum++; // add one because it is a dit } else { // The next three lines handle the automatic speed adjustment: averageDah = (downTime+averageDah) / 2; // running average of dahs dit = averageDah / 3; // normal dit would be this dit = dit * 2; // double it to get the threshold between dits and dahs } } void printCharacter() { justDid = false; // OK to print a space again after this // Punctuation marks will make a BIG myNum if (myNum > 63) { printPunctuation(); // The value we parsed is bigger than our character array // It is probably a punctuation mark so go figure it out. return; // Go back to the main loop(), we're done here. } lcdGuy = mySet[myNum]; // Find the letter in the character set sendToLCD(); // Go figure out where to put in on the display } void printSpace() { if (justDid) return; // only one space, no matter how long the gap justDid = true; // so we don't do this twice // We keep track of the average gap between words and bump it up 20 milliseconds // do avoid false spaces within the word averageWordGap = ((averageWordGap + upTime) / 2) + 20; lastWordCount=0; // start counting length of word again currentLine[letterCount]=' '; // and a space to the variable that stores the current line lastSpace=letterCount; // keep track of this, our last, space // Now we need to clear all the characters out of our last word array for (int i=0; i<20; i++) { lastWord[i]=' '; } lcdGuy=' '; // this is going to go to the LCD // We don't need to print the space if we are at the very end of the line if (letterCount < 20) { sendToLCD(); // go figure out where to put it on the display } } void printPunctuation() { // Punctuation marks are made up of more dits and dahs than // letters and numbers. Rather than extend the character array // out to reach these higher numbers we will simply check for // them here. This funtion only gets called when myNum is greater than 63 // Thanks to Jack Purdum for the changes in this function // The original uses if then statements and only had 3 punctuation // marks. Then as I was copying code off of web sites I added // characters we don't normally see on the air and the list got // a little long. Using 'switch' to handle them is much better. switch (myNum) { case 71: lcdGuy = ':'; break; case 76: lcdGuy = ','; break; case 84: lcdGuy = '!'; break; case 94: lcdGuy = '-'; break; case 97: lcdGuy = 39; // Apostrophe break; case 101: lcdGuy = '@'; break; case 106: lcdGuy = '.'; break; case 115: lcdGuy = '?'; break; case 246: lcdGuy = '$'; break; case 122: lcdGuy = 's'; sendToLCD(); lcdGuy = 'k'; break; default: lcdGuy = '#'; // Should not get here break; } sendToLCD(); // go figure out where to put it on the display } void sendToLCD(){ // Do this only if the character is a 'space' if (lcdGuy > ' '){ lastWord[lastWordCount] = lcdGuy; // store the space at the end of the array if (lastWordCount < lineEnd - 1) { lastWordCount++; // only bump up the counter if we haven't reached the end of the line } } currentLine[letterCount] = lcdGuy; // now store the character in our current line array letterCount++; // we're counting the number of characters on the line // If we have reached the end of the line we will go do some chores if (letterCount == lineEnd) { newLine(); // check for word wrap and get ready for the next line return; // so we don't need to do anything more here } lcd.print(lcdGuy); // print our character at the current cursor location } ////////////////////////////////////////////////////////////////////////////////////////// // The following functions handle word wrapping and line scrolling for a 4 line display // ////////////////////////////////////////////////////////////////////////////////////////// void newLine() { // sendToLCD() will call this routine when we reach the end of the line if (lastSpace == 0){ // We just printed an entire line without any spaces in it. // We cannot word wrap this one so this character has to go at // the beginning of the next line. // First we need to clear all the characters out of our last word array for (int i=0; i<20; i++) { lastWord[i]=' '; } lastWord[0]=lcdGuy; // store this character in the first position of our next word lastWordCount=1; // set the length to 1 } truncateOverFlow(); // Trim off the first part of a word that needs to go on the next line linePrep(); // Store the current line so we can move it up later reprintOverFlow(); // Print the truncated text and space padding on the next line } void truncateOverFlow(){ // Our word is running off the end of the line so we will // chop it off at the last space and put it at the beginning of the next line if (lastSpace==0) {return;} // Don't do this if there was no space in the last line // Move the cursor to the place where the last space was printed on the current line lcd.setCursor(lastSpace,LCDline); letterCount = lastSpace; // Change the letter count to this new shorter length // Print 'spaces' over the top of all the letters we don't want here any more for (int i = lastSpace; i < 20; i++) { lcd.print(' '); // This space goes on the display currentLine[i] = ' '; // This space goes in our array } } void linePrep(){ LCDline++; // This is our line number, we make it one higher // What we do next depends on which line we are moving to // The first three cases are pretty simple because we working on a cleared // screen. When we get to the bottom, though, we need to do more. switch (LCDline) { case 1: // We just finished line 0 // don't need to do anything because this for the top line // it is going to be thrown out when we scroll anyway. break; case 2: // We just finished line 1 // We are going to move the contents of our current line into the line1 array for (int j=0; j<20; j++){ line1[j] = currentLine[j]; } break; case 3: // We just finished line 2 // We are going to move the contents of our current line into the line2 holding bin for (int j=0; j<20; j++){ line2[j] = currentLine[j]; } break; case 4: // We just finished line 3 // We are going to move the contents of our current line into the line3 holding bin for (int j=0; j<20; j++){ line3[j] = currentLine[j]; } //This is our bottom line so we will keep coming back here LCDline = 3; //repeat this line over and over now. There is no such thing as line 4 myScroll(); //move everything up a line so we can do the bottom one again break; } } void myScroll(){ // We will move each line of text up one row int i = 0; // we will use this variables in all our for loops lcd.setCursor(0,0); // Move the cursor to the top left corner of the display lcd.print(line1); // Print line1 here. Line1 is our second line, // our top line is line0 ... on the next scroll // we toss this away so we don't store line0 anywhere // Move everything stored in our line2 array into our line1 array for (i = 0; i < 20; i++) { line1[i] = line2[i]; } lcd.setCursor(0,1); // Move the cursor to the beginning of the second line lcd.print(line1); // Print the new line1 here // Move everything stored in our line3 array into our line2 array for (i = 0; i < 20; i++) { line2[i]=line3[i]; } lcd.setCursor(0,2); // Move the cursor to the beginning of the third line lcd.print(line2); // Print the new line2 here // Move everything stored in our currentLine array into our line3 array for (i = 0; i < 20; i++) { line3[i] = currentLine[i]; } } void reprintOverFlow(){ // Here we put the word that wouldn't fit at the end of the previous line // Back on the display at the beginning of the new line // Load up our current line array with what we have so far for (int i = 0; i < 20; i++) { currentLine[i] = lastWord[i]; } lcd.setCursor(0, LCDline); // Move the cursor to the beginning of our new line lcd.print(lastWord); // Print the stuff we just took off the previous line letterCount = lastWordCount; // Set up our character counter to match the text lcd.setCursor(letterCount, LCDline); lastSpace=0; // clear the last space pointer lastWordCount=0; // clear the last word length }
Someone else made one too: https://www.evernote.com/shard/s145/sh/d55db86a-69a3-4ef5-b082-433d865a9eb7/1932c3268ec30ef166e149de0e8b9620