Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called dots and dashes.
Morse code is named after Samuel Morse, one of the early developers of the system adopted for electrical telegraphy. HAM Operators typically use a telegraph key or paddle to manually input Morse code, which is then transmitted via radio waves.
In one of my previous videos (https://youtu.be/HGZTI0FyOiU) I described a device that automatically decodes Morse code characters into letters, whereby we can follow this type of communication without knowing the Morse code. In order to be able to communicate completely in this way, we also need a device that will convert plain text into a Morse code signal, which is compatible with the radio transmitter. Exactly such a device is described in the project that follows.
The text is entered through a standard ps/2 keyboard, and a 5V relay module is placed at the D7 output, through whose contacts the generated morse signal is sent to the transceiver. The relay contacts behave identically to the telegraph key.
There is also a small piezo buzzer for audio presentation. Specifically, in this case, instead of a relay, I put an LED that visually presents the signs. The typed text is displayed on the LCD display.
The device is really simple to make and consists of only a few components:
- Arduino Nano mikrocontroller board
- LCD Dispaly 128x64 dots with ST7565 driver chip
- ps/2 keyboard female connector
- Led (or 5V relay board
- and small Buzzer
And now let's see how the device works in real conditions.
The text that we type on the keyboard appears on the display. At the same time, we can edit or correct it, and then by pressing Enter, a Morse code is generated from that text, which we simultaneously hear on the buzzer. While the signal is being sent, we can enter new text. The transmission speed can be changed from 1-30 words per minute, and that speed can be changed using the PgDn and PgUp keys.
The device is built into the corresponding housing made of PVC material, and covered with self-adhesive colored wallpaper.
And finally a short conclusion. learning to transmit Morse code with a manual key, and decode it, seems to be an anachronism in the age of computers. In this and the previous project, I presented you a very simple and easy way to enter the world of DX communications without learning Morse code, which requires a lot of time, skill and effort.
/* Arduino morse Encoder
*
*PS2Keyboard library example
PS2Keyboard now requries both pins specified for begin()
keyboard.begin(data_pin, irq_pin);
Valid irq pins:
Arduino Uno: 2, 3
Arduino Due: All pins, except 13 (LED)
Arduino Mega: 2, 3, 18, 19, 20, 21
Teensy 3.0: All pins, except 13 (LED)
Teensy 2.0: 5, 6, 7, 8
Teensy 1.0: 0, 1, 2, 3, 4, 6, 7, 16
Teensy++ 2.0: 0, 1, 2, 3, 18, 19, 36, 37
Teensy++ 1.0: 0, 1, 2, 3, 18, 19, 36, 37
Sanguino: 2, 10, 11
for more information you can read the original wiki in arduino.cc
at http://www.arduino.cc/playground/Main/PS2Keyboard
or http://www.pjrc.com/teensy/td_libs_PS2Keyboard.html
Like the Original library and example this is under LGPL license.
Modified by Cuninganreset@gmail.com on 2010-03-22
Modified by Paul Stoffregen <paul@pjrc.com> June 2010
*/
#include <PS2Keyboard.h>
#include <U8g2lib.h>
#include "Lewis.h"
#include <TimerOne.h>
U8G2_ST7565_ERC12864_1_4W_SW_SPI u8g2 ( U8G2_R0, /* scl=*/ 13 , /* si=*/ 11 , /* cs=*/ 10 , /* rs=*/ 9 , /* rse=*/ 8 ) ;
const int DataPin = 3;
const int IRQpin = 2;
char* znak;
char* wiersz[10]; //char workline*
char* wiersz1[10]; //top line char*
int wiersz_M[10]; //workline in ASCII code
int wiersz_M1[10]; //top line in ASCII code
byte k;
int d, e, i; //helper variables
byte isnm = 7; //number of words per minute
char isnm_str[2];
byte kursor;
const byte index_key = 48; //number of characters in the array
const char* KeyChar[index_key] = {
"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s",
"t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9"," ",
"!","(",")","+",",","-",".","/","=","?","_"};
const int ASCII[index_key] = {
97, 98, 99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,
116,117,118,119,120,121,122, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 32,
33, 40, 41, 43, 44, 45, 46, 47, 61, 63, 95};
PS2Keyboard keyboard;
Lewis Morse;
void setup() {
delay(1000);
keyboard.begin(DataPin, IRQpin);
Serial.begin(9600);
// u8g2.begin ();
// u8g2.setContrast(20);
//Morse.begin(rx_pin, tx_pin, words_per_minute, use_interrupts)
Morse.begin(7,7, isnm, true);
u8g2.begin ();
u8g2.setContrast(40);
//use the TimerOne library for a 100Hz timer interrupt
Timer1.initialize(1000);
Timer1.attachInterrupt(MorseISR);
}
void loop() {
PS2(); //reading characters from the keyboard
if (znak == "enter" ) { Send_Morse();} //sending the line to broadcast
Display(); //display the line
Display(); //display the line
}
void PS2() {
if (keyboard.available()) {
// read the next key
char c = keyboard.read();
d = int(c);
// check for some of the special keys
if (c == PS2_ENTER) {
znak ="enter";
// } else if (c == PS2_TAB) {
// Serial.print("[Tab]");
// } else if (c == PS2_ESC) {
// Serial.print("[ESC]");
} else if (c == PS2_PAGEDOWN) {
isnm--;
if (isnm < 1 ) {isnm = 1;}
Morse.begin(7,7, isnm, true);
} else if (c == PS2_PAGEUP) {
isnm++;
if (isnm > 30) {isnm = 30;}
Morse.begin(7,7, isnm, true);
// } else if (c == PS2_LEFTARROW) {
// Serial.print("[Left]");
// } else if (c == PS2_RIGHTARROW) {
// Serial.print("[Right]");
// } else if (c == PS2_UPARROW) {
// Serial.print("[Up]");
// } else if (c == PS2_DOWNARROW) {
// Serial.print("[Down]");
} else if (c == PS2_DELETE) {
znak = "back";
i--;
znak = " ";
wiersz[i] = znak;
wiersz_M[i] = d;
} else {
// otherwise substitute a regular letter
getKeyChar(); //converting char to char*
wiersz[i] = znak;
wiersz_M[i] = d;
if (i > 9) {i = -1;}
if (znak == "enter"){i = -1;}
if (znak != "back" && znak != "enter") {i++;} //increase character counter
}
}
}
void Display() { //display data on the LCD
kursor++;
if (kursor >20){ kursor = 0;}
sprintf(isnm_str,"%d", isnm); //converting a number to a string
u8g2.firstPage();
do {
u8g2.setFont(u8g2_font_10x20_tr);
u8g2.drawStr(0, 15, "Morse");
u8g2.drawStr(75, 15, isnm_str);
u8g2.drawStr(98, 15, "w/m");
for (k = 0; k < 10; k++){
u8g2.drawStr(k*10, 40, wiersz1[k] );
u8g2.drawStr(k*10, 60, wiersz[k] );
}
if (kursor<15){u8g2.drawStr(i*10, 60, "_" );} //display the cursor
if (kursor>5){u8g2.drawStr(i*10, 60, " " );} //cursor blinking
} while ( u8g2.nextPage() );
}
void Send_Morse(){
znak = " ";
for (int k = 0; k < 10; k++) {
wiersz1[k] = " "; //cash
wiersz1[k] = wiersz[k]; //rewriting characters from the working line to the top
wiersz[k] = " "; //delete work line
wiersz_M1[k] = 32; //delete ASCII top line
wiersz_M1[k] = wiersz_M[k]; //rewrite ASCII from the working line to the top line
wiersz_M[k] = 32; //delete ASCII worklineroboczego
}
for (int k = 1; k < 10; k++){
e = wiersz_M1[k];
Morse.write(e); //morse the contents of the top line
}
i = 0;
}
void MorseISR(){
Morse.timerISR(); //function triggered by interrupts (keyboard)
}
void getKeyChar() { //converting a key code into a letter and an ASCII code
for (k = 0; k <= index_key; k++){
if (ASCII[k] == d) { znak = KeyChar[k];} //convert key code to letter
}
k = 0;
}
