Electronics Hobby Circuits

DIY CW Keyer for Ham Radio

2024-01-25T04:48:00.000-08:00

Telegraphic CW keyer for HamRadio

( Based on Cheap Micro controller - ATTiny13 and 8 Pin IC )

Main FEATURES

1. Uses Left and Right switch paddles for sending CW ( telegraphy codes)

2. Works in 5V dc SUPPLY

3. Very less power consumption

4. Built in SIDE TONE

5. Can Adjust Speed of sending in real time, using potentio-meter rotary control

6. Can connect to Ham Radio for sending CW

7. Can be used for CW learning / training

Get More Details in Link

https://github.com/vu3ave/ATTiny13-keyer

https://docs.google.com/document/d/10ovmRRI6KD7Igxck4vUOjzKiFODersbDDlenNkgg5Q4/edit?pli=1#heading=h.lfnnqlbxlyqh

CODE USED IN THIS ATTIY CIRCUIT

  
// Simple Iambic Keyer v1.00
// by Ernest PA3HCM
// modified by VU3AVE for  ATTINY13 (1.2 MHz internal clock 
// speed) IC use, which is much cheaper than arduino board


//  You can edit below 2 lines

int Maximum_speed_WPM=30;
int Minimum_speed_WPM=3;

// DONT edit below this line

/*
 1) DOT( dit) is 5th physical pin of the IC ATTINY13
 2) DASH is 6th pin physical pin of the IC ATTINY13
 3) CW out put is at 7th physical pin of the IC ATTINY13
 4) 10k potentiometer(speed control) , center lead connection
    to 2nd physical pin of the IC ATTINY13
 5) Audio tone in output at 3rd physical pin of the IC ATTINY13
 */
#define P_DOT    0   // Connects to the dot lever of the paddle
#define P_DASH   1   // Connects to the dash lever of the paddle
#define P_CW     2   // Output of the keyer, connect to your radio
#define P_SPEED A3   // Attached to center pin of potmeter, 
                     // allows you to set the keying speed.
int speed;
#define P_AUDIO 4   // Audio output through speaker // for ATTINY13

void setup()
{
  pinMode(P_DOT, INPUT);
  pinMode(P_DASH, INPUT); 
  pinMode(P_AUDIO, OUTPUT);
  pinMode(P_CW, OUTPUT);
 
}


void loop()
{
speed = 60000 / (map(analogRead(P_SPEED), 0, 1023, Maximum_speed_WPM, Minimum_speed_WPM) * 73);

  // speed = 100;
 if(!digitalRead(P_DOT))        // If the dot lever is presssed..
     {
    keyAndBeep(speed);           // ... send a dot at the given speed
    delay(speed);                //     and wait before sending next
     }


  
if(!digitalRead(P_DASH))       // If the dash lever is pressed...
    {
   keyAndBeep(speed*3);         // ... send a dash at the given speed
   delay(speed);                //     and wait before sending next
    }
  
}


// Key the transmitter and sound a beep
void keyAndBeep(int speed)
{
  digitalWrite(P_CW, HIGH);            // Key down
  for (int i=0; i < speed; i++)    // Beep loop
  {
   digitalWrite(P_AUDIO, HIGH);
   delay(1);
   digitalWrite(P_AUDIO, LOW);
   delay(1);
  }
   digitalWrite(P_CW, LOW);             // Key up
 }
 
 /////////////code complete////////////



EXPLANATION OF CODE AND CONNECTION IN HARDWARE SIDE



#define P_DOT    0   // Connects to the dot lever of the paddle 
#define P_DASH   1   // Connects to the dash lever of the paddle 


This means: you have to connect digital pin 0 to DOT sending
connector of external paddle key -  Also Place a 10 K ohm resistor
from pin 0 to +5V of the circuit board (called pull up resistor)

This means: you have to connect digital pin 1 to DASH sending
connector of external paddle key-  Also Place a 10 K ohm resistor
from pin 0 to +5V of the circuit board (called pull up resistor)




EXPLANATION OF CODE AND CONNECTION IN HARDWARE SIDE


#define P_CW     2   // Output of the keyer, connect to your radio 
#define P_SPEED A3   // Attached to center pin of potmeteru
                     // , allows you to set the keying speed.
#define P_AUDIO 4   // Audio output through speaker



This means: you have to connect digital pin 2 to ge CW on/off
( 0 - 5V ) digital output. you can use it to switch a relay to
trigger cw input of your wireless set

This means: you have to connect digital pin A3 to variation
pin (center pin) of a volume control variable resistor (10 k Pot)
the other free two terminals to 0v and 5V

This means: Connect a 8 ohm speaker through a 10 micro farad 
capacitor from digital pin 4. Other end of the speaker to
GND ( negative terminal of the circuit board)

VIDEO DEMO OF ACTUAL CIRCUIT MADE BY ME

Ham radio, or amateur radio, is a hobby where people communicate with each other using radio waves. One of the most important and traditional modes of communication in ham radio is CW telegraphy, which uses Morse code for communication.

Is straight key / electronic key is better

for sending CW (Morse code)

It depends on your individual preferences and goals.
Here's a breakdown of the pros and cons of each:

Straight Key:

Pros:

Develops good fist: Using a straight key forces you to develop good timing and control over your sending, resulting in a clear and consistent "fist" (sending style).

Sense of accomplishment: Mastering the straight key can be a rewarding challenge and a source of pride for many CW operators.

Portable and simple: Straight keys are typically small and lightweight, making them easy to take with you and operate in the field. They also require no batteries or external power.

Cons:

Slower sending speeds: Straight keys typically limit sending speeds to around 25-30 wpm (words per minute). Electronic keys can reach much higher speeds (up to 60 wpm or more).

More physically demanding: Sending with a straight key requires sustained physical effort, which can be tiring for long periods.

Can be challenging to learn: Developing good fist with a straight key takes time and practice.

Electronic Key:

Pros:

Faster sending speeds: Electronic keys can significantly increase your sending speed, allowing you to make more contacts and participate in faster-paced QSOs (conversations).

Reduced physical effort: Electronic keys require minimal physical effort to operate, making them less tiring for long sessions.

Flexibility: Many electronic keys offer features like adjustable dits/dahs ratios, memory keyers, and iambic keying (which automatically spaces the dits within a dah), allowing you to customize your sending style.

Cons:

Can be expensive: (Our case is different ) High-quality electronic keys can be quite expensive compared to straight keys.

May not develop good fist: Reliance on an electronic key can hinder the development of good timing and fist.

Requires batteries or power: Electronic keys need batteries or an external power source to operate.

Micro Controller : ATtiny 13

ATTINY13 IC

The AtTiny13 is a high-performance, low-power 8-bit AVR RISC-based micro controller from Microchip Technology. It's a popular choice for hobbyists and makers due to its small size, ease of use, and affordability. Here are some of its key features:

Low operating voltage (2.7V to 5.5V): This makes it suitable for battery-powered projects.
Multiple power-saving modes: These allow you to put the micro controller into a low-power state when not needed, extending battery life.
Brown-out detection: This protects the micro controller from voltage dips that could cause it to malfunction.

CIRCUIT DIAGRAM

PROGRAME CODE USED

https://github.com/vu3ave/ATTiny13-keyer

Contact Me :

Anish VR,

Vazheparambil, poosaripady

near llittle heart school

North Paravur

KERALA - INDIA

pin: 683513

MOBILE/Whatsapp number : 91 9995957776

email: vu3ave@gmail.com , anishvrajan@gmail.com

USB Keyboard telegraphic CW keyer

2024-01-24T03:18:00.000-08:00

USB Keyboard telegraphic CW keyer for Ham radios

Circuit and Program by VU3AVE
Anish VR, North Paravur
Phone: +91 9995957776

Use USB / PS2 keyboard to send cw message : Using Arduino nano

Thanks to VU3AJU Ajan PJ, Moothakunnam for code support

Find video details at: www.youtube.com/watch?v=Y5XYUysJYd8

Sending CW in ameature radio

Using a Computer Keyboard (PS/2 model or USB model)

for typing and sending cw telegraphic codes is the discussion here.

Code reference from: https://www.codeproject.com/Articles/1250929/Sending-Morse-Code-with-your-Arduino

http://www.arduino.cc/playground/Main/PS2Keyboard

http://www.pjrc.com/teensy/td_libs_PS2Keyboard.html

This code modified for “String” variable for convenience of adding a keyboard

Support ( thanks to AJAN PJ, VU3AJU )

Features

Use USB or PS2 keyboard to send CW directly
Speed up / down using arrow keys
Preset messages sending

Hardware

Arduino nano
PS2 keyboard
8 ohm speaker
Buzzer (optional)
BC148 (1 nos), 10 K ohm ( 2 nos)

Wire Connections:

PS2 Keyboard - to - Arduino nano

USB keyboard - to - Arduino nano

V = connected to + 5V of Arduino

G - Ground = connected to GND of Arduino

D - Data = connected Pin = 8 DataPin of Arduino [ or D+ pin of USB keyboard ]

C - Clock = connected Pin = 3 , IRQpin of Arduino [ or D- pin of USB keyboard ]

for more information you can read the original wiki in arduino.cc at

http://www.arduino.cc/playground/Main/PS2Keyboard

http://www.pjrc.com/teensy/td_libs_PS2Keyboard.html

Speaker connection

Pin 7 of .Arduino nano is connected through a 100 mico farad capacitor to 8 ohm speaker, and other end of the speaker is connected to ground, GND

This provide tone() while speeding Up and Down keyer speed (WPM)

CW Key connection

Pin 13 of Arduino is connected through 10 K ohm resistance to Base of BC148 transistor. Its Emitter is connected to common ground, GND.

Collector if BC148 connected to CW KEY , centre lead of the Transceiver RIG

Arduino is given +5 volt via its own USB connector.

IMPORTANT

1. Used shield wire for PTT / KEY outgoing wires

2. Use RF choke, by looping wires through toroids, in 9V DC line

Hardware used

Arduino nano

Programming Software

Arduino IDE ( www.arduino.cc )

Connection Diagram

USB Keyboard Modification

Popular keyboard nowadays is the USB keyboard.

Use the connections change as the below figure and this programme

Work smoothly on the usb keyboard too!!

Arduino nano PIN	USB keyboard Pin	PS2 keyboard Pin
5V	5V	5V
GND	GND	GND
D3	- D	Clock (c)
D8	+ D	Data (d)

Use " ps2keyboard "Library by Christian Weichel, Paul Stoffregan

Source Code DOWNLOAD FROM GITHUB

// code begin here

#include <PS2Keyboard.h>

// PS2 KEYBOARD

const int DataPin = 8; // DATA out of ps2 keyboard

const int IRQpin = 3; // for arduino nano //clock out of ps2 keyboard

PS2Keyboard keyboard;

// AUTOMATIC KEYER USING PADDLE AND USB/PS2 KEYBOARD

int Maximum_speed_WPM=30;

int Minimum_speed_WPM=3;

int P_DOT = 2; // Connects to the dot lever of the paddle

int P_DASH = 4; // Connects to the dash lever of the paddle 3 to 4

int P_AUDIO = 7; // Audio output

// int P_AUDIO = 12; // Audio output

int P_CW = 13; // Output of the keyer, connect to your radio

#define P_SPEED A0 // Attached to center pin of potmeter, allows you

int speed;

////////////////////////////// CW sender/////

String mappings[] = {

".-", // A

"-...",

"-.-.",

"-..",

".",

"..-.",

"--.",

"....",

"..",

".---",

"-.-",

".-..",

"--",

"-.",

"---",

".--.",

"--.-",

".-.",

"...",

"-",

"..-",

"...-",

".--",

"-..-",

"-.--",

"--..", // Z

".----", // 1

"..---",

"...--",

"....-",

".....",

"-....",

"--...",

"---..",

"----.",

"-----", // 0

"..--..", // ?

".-.-.-", // .

"--..--", // ,

"-..-.", // /

"...-.-" // @

};

String morsecode;

String message;

const String characters = "abcdefghijklmnopqrstuvwxyz1234567890?.,/";

int sm_time;

int time_step=100; // initial timer

int TIME_UNIT;

String inputString = ""; // a String to hold incoming data

bool stringComplete = false; // whether the string is complete

////////////////////////////

int KEY_PIN=13; // relay drive to transimit cw in port

// tone frequency for speaker

int notes[] = {

1047, 1319, 1175, 1568

};

void setup() {

delay(1000);

keyboard.begin(DataPin, IRQpin);

Serial.begin(9600);

Serial.println("Keyboard Test:");

pinMode(13, OUTPUT); // connect a buzzer at pin 13 to listen cw

pinMode(9, OUTPUT); // connect and LED in pin 9

pinMode(6, OUTPUT); // Local speaker or LED

// reserve 200 bytes for the inputString:

inputString.reserve(200);

pinMode(P_DOT, INPUT);

pinMode(P_DASH, INPUT);

pinMode(P_AUDIO, OUTPUT);

digitalWrite(P_CW, LOW); // Start with key up

// sound welcome tone

speeddown();

speedup();

// speeddown_mute();

speedup_mute();

}

void loop() {

//// LAMBIC KEYER START

speed = 60000 / (map(analogRead(P_SPEED), 0, 1023, Maximum_speed_WPM, Minimum_speed_WPM) * 73);

// speed = 100;

if(!digitalRead(P_DOT)) // If the dot lever is presssed..

{

keyAndBeep(speed); // ... send a dot at the given speed

delay(speed); // and wait before sending next

}

if(!digitalRead(P_DASH)) // If the dash lever is pressed...

{

keyAndBeep(speed*3); // ... send a dash at the given speed

delay(speed); // and wait before sending next

}

//// LAMBIC KEYER CLOSE

// print the string when a newline arrives:

if (stringComplete)

{

Serial.println(inputString);

message=inputString;

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

// clear the string:

inputString = "";

stringComplete = false;

}

// print the string when a newline arrives:

if (keyboard.available()) {

// read the next key

char c = keyboard.read();

// check for some of the special keys

if (c == PS2_ENTER) {

// Serial.println();

} else if (c == PS2_TAB) {

Serial.print("[Tab]");

message="vu2acc";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == PS2_ESC) {

// Serial.print("[ESC]");

message="hi";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == PS2_PAGEDOWN) {

//Serial.print("[PgDn]");

message="qrz?";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == PS2_PAGEUP) {

//Serial.print("[PgUp]");

message="cq cq cq de vu2acc vu2acc vu2acc pse k";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == PS2_LEFTARROW) {

Serial.print("[Left]");

} else if (c == PS2_RIGHTARROW) {

Serial.print("[Right]");

} else if (c == PS2_DELETE) {

// Serial.print("[Del/Backspace]");

message="de vu2acc tks fer qso 73 tu i";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == PS2_UPARROW) {

//Serial.print("[Up]- Speed UP");

speedup();

} else if (c == PS2_DOWNARROW) {

//Serial.print("[Down]- Speed DOWN");

speeddown();

} else if (c =='=') {

//Serial.print("CQ Call");

message="cq cq cq de vu2acc vu2acc vu2acc k";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == '?') {

// Serial.print("qrz call");

message="qrz ? de vu2acc k";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == '-') {

message="de vu2acc tks fer qso 73 tu i";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else if (c == '%') {

message="hi";

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

} else {

// otherwise, just print all normal characters

Serial.print(c);

///test

message=c;

digitalWrite(9,HIGH);

delay(100);

int result= messagetocw();

digitalWrite(9,LOW);

///test

}

}// 'if' is close

}// LOOP() close

////LAMBIC FUNCTIONS START

// Key the transmitter and sound a beep

void keyAndBeep(int speed)

{

digitalWrite(P_CW, HIGH); // Key down

for (int i=0; i < speed; i++) // Beep loop

{

digitalWrite(P_AUDIO, HIGH);

delay(1);

digitalWrite(P_AUDIO, LOW);

delay(1);

}

digitalWrite(P_CW, LOW); // Key up

}

////LAMBIC FUNCTIONS CLOSE

void speedup()

{

time_step=time_step-10;

if(time_step<=10)

{

time_step=10;

}

for (int thisSensor = 0; thisSensor < 4; thisSensor++) {

tone(7, notes[thisSensor]);

delay(time_step);

noTone(7);

}

void speeddown()

{

time_step=time_step+10;

for (int thisSensor = 3; thisSensor >= 0; thisSensor--) {

tone(7, notes[thisSensor]);

delay(time_step);

noTone(7);

}

void speedup_mute(){

time_step=time_step-10;

if(time_step<=10)

{

time_step=10;

}

int messagetocw()

{

// FUNCTION messagetocw() START

// int size = strlen(message);

int size = message.length();

int TIME_UNIT = 50; // default time for DIT

///

if(TIME_UNIT==time_step)

{

}

else

{

TIME_UNIT=time_step;

}

///

if(TIME_UNIT<=10)

{

TIME_UNIT=10;

time_step=10;

}

///

const int DOT = TIME_UNIT;

const int DASH = 3 * TIME_UNIT;

const int SYMBOL_SPACE = TIME_UNIT;

const int LETTER_SPACE = 3 * TIME_UNIT - SYMBOL_SPACE;

const int WORD_SPACE = 7 * TIME_UNIT - LETTER_SPACE;

message.toLowerCase();

for (int i = 0; i < size; i++) {

// const char* ch = strchr(characters, tolower(message[i]));

char ch = characters.charAt(characters.indexOf(message.charAt(i)));//

// if (ch != NULL){

if (ch != '\0'){

// int position = ch-characters;

int position = characters.indexOf(message.charAt(i));

morsecode = mappings[position];

// int count = strlen(morsecode);

int count = morsecode.length();

//Serial.print("symbol ");

//Serial.print(message[i]);

//Serial.print(" is in position ");

//Serial.print(position);

//Serial.print("\n");

//Serial.print(morsecode);

//Serial.print("\n---------------\n");

for( int j=0; j< count; j++)

{

char symbol = morsecode[j];

if(symbol =='.')

{

sm_time = DOT;

}

if(symbol =='-')

{

sm_time = DASH;

}

digitalWrite(KEY_PIN, HIGH);

delay(sm_time);

digitalWrite(KEY_PIN, LOW);

delay(SYMBOL_SPACE);

}// for loop close2

delay(LETTER_SPACE);

}

delay(WORD_SPACE);

}// for loop close1

} // FUNCTION messagetocw() close

SerialEvent occurs whenever a new data comes in the hardware serial RX. This routine is run between each time loop() runs, so using delay inside loop can delay response. Multiple bytes of data may be available.

void serialEvent()

{

while (Serial.available()) {

// get the new byte:

char inChar = (char)Serial.read();

// add it to the inputString:

inputString += inChar;

// if the incoming character is a newline, set a flag so the main loop can

// do something about it:

if (inChar == '\n') {

stringComplete = true;

}

// thanks de vu3ave

// code complete

Thank you

Anish VR

VU3AVE

Mobile phone: 91 9995957776

vu3ave@gmail.com

Use this code as a reference, make changes as necessary

FM Transmitter using 2N918

2011-12-20T18:50:00.000-08:00

In my college days I have made 2 transistor FM transmitter that have a range of 500meter. It works on 3v battery and used 2N918 transistor. The circuit was from the Malayalam magazine "Electronics for you". I made this circuit on 1995, as my B.Sc Physics, Electronic Project.

FM Transmitter with 2N918, 3V DC

The working circuit for FM Transmitter

Now I am on a project of making 3 transistor FM with 2N2222. Here the first transistor acting as audio amplifier and second one acting as VHF oscillator. Third one acting as buffer /RF amplifier

Water level Controller

2011-11-26T22:59:00.000-08:00

Water level Controller using CD4001

Working details :

1. Motor operates only if, Reservoir tank is not empty. If it empty while running motor pump, it is switched off

2. When water level at Low level indicated, Motor starts ( If also, reservoir is not empty)

3. When water level reaches High level, Motor stops.

Additional Features:

1. Circuit is compensated for, false switching due to ripples in water tank.

2. Only DC, small voltage is used in circuit and sensing leads.

3. Low current (Serried through 1M ohm to 100 M ohm resistance) sensing

4. Sensing by grounding method is used, so no charge accumulation any where

5. LED indication of Hi, Low, Reservoir Low, Motor status.

6. Manual Operation of Motor using parallel switch.

Circuit Diagram

Truth Table

Hi Level Low Level Low level (R) Motor

False True False ON

After Motor starts, it continue to be ON

False False False ON

Motor continue to run, till the situation as below

True False False OFF

Or in a situation, if the Reservoir is go empty

False False True OFF

Components and Board

I started assembling this circuit today. I used 10 M resistors for all 3 resistors.

Tested it with water taken in a glass. Worked good.

Found that there is no problem even in case the two sensor leads touch directly each other. It is becouse, of the High value resistor (10M) limits the current through circuit.

Circuit was done in a general purpose PCB, with IC base. To get 9V supply, a regulator IC

was used. I tested the circuit with an LED (Green) at the pin 11 of the IC, with a resistor in series.

Testing connections before giving power supply

The Circuit worked good, with 30 meters of cable routed to the Top tank. Water Level Controller fixed near the water pump. Additional indicator LED s were placed on front panel to visual indication of Motor ON, and Power ON for the controller circuit. The same cable was routed for bottom reservoir tank. So the project is successful, as far as it is completed and functioning well.

Electronics Hobby Circuits

DIY CW Keyer for Ham Radio

Telegraphic CW keyer for HamRadio

( Based on Cheap Micro controller - ATTiny13 and 8 Pin IC )

Main FEATURES

Get More Details in Link

https://github.com/vu3ave/ATTiny13-keyer

VIDEO DEMO OF ACTUAL CIRCUIT MADE BY ME

Is straight key / electronic key is better

for sending CW (Morse code)

It depends on your individual preferences and goals. Here's a breakdown of the pros and cons of each:

Straight Key:

Electronic Key:

Micro Controller : ATtiny 13

CIRCUIT DIAGRAM

PROGRAME CODE USED

https://github.com/vu3ave/ATTiny13-keyer

Contact Me :

USB Keyboard telegraphic CW keyer

USB Keyboard telegraphic CW keyer for Ham radios

Code reference from: https://www.codeproject.com/Articles/1250929/Sending-Morse-Code-with-your-Arduino

Connection Diagram

Use " ps2keyboard "Library by Christian Weichel, Paul Stoffregan

Source Code DOWNLOAD FROM GITHUB

FM Transmitter using 2N918

Water level Controller

It depends on your individual preferences and goals.
Here's a breakdown of the pros and cons of each: