Homebrew 80/40m SSB/CW Base Rig

Audio Amplifier

Another audio amplifier option.

Double Balanced Mixers

Plessey Bidirectional IF Amplifiers

Mic Amp

RF Power Amp

Low Pass Filters

#include <Wire.h>

#include <SPI.h>

#include <LiquidCrystal_I2C.h>

#include <si5351.h>

const uint32_t band80mStart = 3500000;    // start of 80m

const uint32_t band80mEnd = 3900000;      // end of 80m

const uint32_t band40mStart = 7000000;    // start of 40m

const uint32_t band40mEnd = 7300000;      // end of 40m

const uint32_t bandInit =  3700000;       // where to initially set the frequency

volatile long oldfreq = 0;

volatile long old80mfreq = 3700000;

volatile long old40mfreq = 7100000;

volatile long currentfreq = 0;

volatile int updatedisplay = 0;

volatile int TX = 0;

volatile int oldTX = 0;

volatile int mode = 0;

volatile int oldmode = 0;

volatile int band = 0;

volatile int oldband = 0;

volatile uint32_t freq = bandInit ;     // this is a variable (changes) - set it to the beginning of the band

volatile uint32_t radix = 1000;         // how much to change the frequency by, clicking the rotary encoder will change this.

volatile uint32_t SSB_BFO_freq = 8999700;   // 8998050 (filter centre) + 2700/2 + 300

//volatile uint32_t SSB_BFO_freq = 9000300;   // 8998050 (filter centre) + 2700/2 + 300

volatile uint32_t CW_BFO_freq = 8997336;    // 8996750 (filter centre) + 700 - 114 (from test)

static const uint32_t CW_Filter_CentreFreq = 8996750;

// Rotary encoder pins and other inputs

static const int rotAPin = 2;

static const int rotBPin = 3;

static const int pushPin = 4;

// Mode switches

static const int BandPin = 5;

static const int ModePin = 6;

// Discrete Outputs

static const int CrystalFilterSelectPin = 10;

static const int PTTPin = 11;

// Rotary encoder variables, used by interrupt routines

volatile int rotState = 0;

volatile int rotAval = 1;

volatile int rotBval = 1;

// Instantiate the Objects

LiquidCrystal_I2C lcd(0x27, 16, 2);

Si5351 si5351;

void setup()

{

  // Set up frequency and radix switches

  pinMode(rotAPin, INPUT);

  pinMode(rotBPin, INPUT);

  pinMode(pushPin, INPUT);

  pinMode(ModePin, INPUT);

  pinMode(BandPin, INPUT);

  pinMode(PTTPin, INPUT);

  pinMode(CrystalFilterSelectPin, OUTPUT);

  // Set up pull-up resistors on inputs

  digitalWrite(rotAPin, HIGH);

  digitalWrite(rotBPin, HIGH);

  digitalWrite(pushPin, HIGH);

  digitalWrite(ModePin, HIGH);

  digitalWrite(BandPin, HIGH);

  digitalWrite(PTTPin, HIGH);

  digitalWrite(CrystalFilterSelectPin, LOW);

  // Set up interrupt pins

  attachInterrupt(digitalPinToInterrupt(rotAPin), ISRrotAChange, CHANGE);

  attachInterrupt(digitalPinToInterrupt(rotBPin), ISRrotBChange, CHANGE);

  // Initialize the display

  lcd.begin();

  lcd.backlight();

  lcd.cursor();

  UpdateDisplay();

  delay(1000);

  // Initialize the DDS

  si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0);

  si5351.set_correction(35980);

  si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);

  si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_8MA);

  si5351.drive_strength(SI5351_CLK2, SI5351_DRIVE_8MA);

//  si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_6MA);

//  si5351.drive_strength(SI5351_CLK2, SI5351_DRIVE_6MA);  si5351.set_freq((freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK0);

  si5351.set_freq((SSB_BFO_freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK2);

}

void loop()

{

  currentfreq = getfreq();                    // Interrupt safe method to get the current frequency

  if (currentfreq != oldfreq)

  {

    UpdateDisplay();

    SendFrequency();

    oldfreq = currentfreq;

  }

  if (digitalRead(pushPin) == LOW)

  {

    delay(10);

    while (digitalRead(pushPin) == LOW)

    {

      if (updatedisplay == 1)

      {

        UpdateDisplay();

        updatedisplay = 0;

      }

    }

    delay(50);

  }

  if (digitalRead(PTTPin) == HIGH)

    TX = 1;

  else

    TX = 0;

  if (digitalRead(ModePin) == LOW)

  {

    mode = 1;                                       // 0 = LSB, 1 = CW

    digitalWrite(CrystalFilterSelectPin, HIGH);     // Select CW filter

  }

  else

  {

    mode = 0;

    digitalWrite(CrystalFilterSelectPin, LOW);      // Select SSB filter

  }

  if (digitalRead(BandPin) == LOW)

    band = 1;                                       // 0 = 80m, 1 = 40m

  else

    band = 0;

  if (TX != oldTX)                              // Only update the display on mode change

  {

    //UpdateMode();

    UpdateDisplay();

    oldTX = TX;

  }

  if (mode != oldmode)                              // Only update the display on mode change

  {

    //UpdateMode();

    UpdateDisplay();

    SendFrequency();

    oldmode = mode;

  }

  if (band != oldband)                          // Only update the display on band change

  {

    // 0 = 80m, 1 = 40m

    if (band == 0)  // now 80m was 40m

    {

      old40mfreq = freq;

      freq = old80mfreq;

    }

    if (band == 1)  // now 40m was 80m

    {

      old80mfreq = freq;

      freq = old40mfreq;

    }

    UpdateDisplay();

    oldband = band;

  }

}

long getfreq()

{

  long temp_freq;

  cli();

  temp_freq = freq;

  sei();

  return temp_freq;

}

// Interrupt routines

void ISRrotAChange()

{

  if (digitalRead(rotAPin))

  {

    rotAval = 1;

    UpdateRot();

  }

  else

  {

    rotAval = 0;

    UpdateRot();

  }

}

void ISRrotBChange()

{

  if (digitalRead(rotBPin))

  {

    rotBval = 1;

    UpdateRot();

  }

  else

  {

    rotBval = 0;

    UpdateRot();

  }

}

void UpdateRot()

{

  switch (rotState)

  {

    case 0:                                         // Idle state, look for direction

      if (!rotBval)

        rotState = 1;                               // CW 1

      if (!rotAval)

        rotState = 11;                              // CCW 1

      break;

    case 1:                                         // CW, wait for A low while B is low

      if (!rotBval)

      {

        if (!rotAval)

        {

          // either increment radixindex or freq

          if (digitalRead(pushPin) == LOW)

          {

            updatedisplay = 1;

            if (radix == 1000000)

              radix = 100000;

            else if (radix == 100000)

              radix = 10000;

            else if (radix == 10000)

              radix = 1000;

            else if (radix == 1000)

              radix = 100;

            else if (radix == 100)

              radix = 10;

            else if (radix == 10)

              radix = 1;

            else

              radix = 1000000;

          }

          else

          {

            freq = (freq + radix);

            if (band == 0)          // 80m

              if (freq > band80mEnd)

                freq = band80mEnd;

            if (band == 1)          // 80m

              if (freq > band40mEnd)

                freq = band40mEnd;

          }

          rotState = 2;                             // CW 2

        }

      }

      else if (rotAval)

        rotState = 0;                               // It was just a glitch on B, go back to start

      break;

    case 2:                                         // CW, wait for B high

      if (rotBval)

        rotState = 3;                               // CW 3

      break;

    case 3:                                         // CW, wait for A high

      if (rotAval)

        rotState = 0;                               // back to idle (detent) state

      break;

    case 11:                                        // CCW, wait for B low while A is low

      if (!rotAval)

      {

        if (!rotBval)

        {

          // either decrement radixindex or freq

          if (digitalRead(pushPin) == LOW)

          {

            updatedisplay = 1;

            if (radix == 1)

              radix = 10;

            else if (radix == 10)

              radix = 100;

            else if (radix == 100)

              radix = 1000;

            else if (radix == 1000)

              radix = 10000;

            else if (radix == 10000)

              radix = 100000;

            else if (radix == 100000)

              radix = 1000000;

            else

              radix = 1;

          }

          else

          {

            freq = (freq - radix);

            if (band == 0)          // 80m

              if (freq < band80mStart)

                freq = band80mStart;

            if (band == 1)          // 80m

              if (freq < band40mStart)

                freq = band40mStart;

          }

          rotState = 12;                            // CCW 2

        }

      }

      else if (rotBval)

        rotState = 0;                               // It was just a glitch on A, go back to start

      break;

    case 12:                                        // CCW, wait for A high

      if (rotAval)

        rotState = 13;                              // CCW 3

      break;

    case 13:                                        // CCW, wait for B high

      if (rotBval)

        rotState = 0;                               // back to idle (detent) state

      break;

  }

}

void UpdateDisplay()

{

  lcd.setCursor(0, 0);

  lcd.print("        ");

  lcd.setCursor(0, 0);

  lcd.print(freq);

  lcd.setCursor(10, 0);

  lcd.print("ZL2CTM");

  lcd.setCursor(0, 1);

  lcd.print("   ");

  lcd.setCursor(0, 1);

  lcd.setCursor(0, 1);

  if (mode == 0)

    lcd.print("LSB");

  if (mode == 1)

    lcd.print("CW ");

  lcd.setCursor(5, 1);

  lcd.print("  ");

  lcd.setCursor(5, 1);

  if (TX == 1)

    lcd.print("TX");

  if (freq > 9999999)

  {

    if (radix == 1)

      lcd.setCursor(7, 0);

    if (radix == 10)

      lcd.setCursor(6, 0);

    if (radix == 100)

      lcd.setCursor(5, 0);

    if (radix == 1000)

      lcd.setCursor(4, 0);

    if (radix == 10000)

      lcd.setCursor(3, 0);

    if (radix == 100000)

      lcd.setCursor(2, 0);

    if (radix == 1000000)

      lcd.setCursor(1, 0);

  }

  if (freq <= 9999999)

  {

    if (radix == 1)

      lcd.setCursor(6, 0);

    if (radix == 10)

      lcd.setCursor(5, 0);

    if (radix == 100)

      lcd.setCursor(4, 0);

    if (radix == 1000)

      lcd.setCursor(3, 0);

    if (radix == 10000)

      lcd.setCursor(2, 0);

    if (radix == 100000)

      lcd.setCursor(1, 0);

    if (radix == 1000000)

      lcd.setCursor(0, 0);

  }

}

void SendFrequency()

{

  // CW_BFO_freq = 8997336;    // 8996750 (filter centre) + 700 - 114 (from test)

  // SSB_BFO_freq = 8999700;   // 8998050 (filter centre) + 2700/2 + 300

  // CW_Filter_CentreFreq = 8996750;

  if (mode == 1)      // CW

  {

    si5351.set_freq(((CW_Filter_CentreFreq - freq) * 100ULL), SI5351_PLL_FIXED, SI5351_CLK0);

    si5351.set_freq((CW_BFO_freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK2);

  }

  else                // SSB

  {

    si5351.set_freq(((SSB_BFO_freq - freq) * 100ULL), SI5351_PLL_FIXED, SI5351_CLK0);

    si5351.set_freq((SSB_BFO_freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK2);

  }

}

Portable 40m CW Transceiver

#include <Wire.h>
#include <SPI.h>
#include <TM1637Display.h>
#include <si5351.h>
#include "LowPower.h"

const uint32_t bandStart = 7000000;     // start of 80m
const uint32_t bandEnd =   7400000;     // end of 80m
const uint32_t bandInit =  7025000;     // where to initially set the frequency
volatile long oldfreq = 0;
volatile long currentfreq = 0;
volatile int currentTime = 0;
volatile int previousTime = 0;
volatile int elapsed = 0;
volatile int QSK_Timer = 1000;
int PTT = 0;

volatile uint32_t freq = bandInit ;     // this is a variable (changes) - set it to the beginning of the band
volatile uint32_t radix = 1000;         // how much to change the frequency by, clicking the rotary encoder will change this.

volatile uint32_t LSB_IF_freq = 9011500;    // Crystal filter centre freq
volatile uint32_t LSB_BFO_freq = 9000000;   // Crystal filter centre freq

// Rotary encoder pins and other inputs
static const int rotBPin = 2;
static const int rotAPin = 3;
static const int pushPin = 4;
static const int KeyInput = 7;
static const int PTTOutput = 8;
static const int brightnessPin = A3;
static const int tunespeedLED = A2;
static const int gnd = 10;
static const int vcc = 11;
static const int DIO = 12;
static const int CLK = 13;

// Rotary encoder variables, used by interrupt routines
volatile int rotState = 0;
volatile int rotAval = 1;
volatile int rotBval = 1;


volatile long remainder = 0;
volatile long OnesHz = 0;
volatile long TensHz = 0;
volatile long HundredsHz = 0;
volatile long OneskHz = 0;
volatile long TenskHz = 0;
volatile long HundredskHz = 0;
volatile long OnesMHz = 0;
volatile long TensMHz = 0;
volatile int Brightness = 3;
volatile int batterySave = 0;

// Instantiate the Objects
TM1637Display display(CLK, DIO);    // CLK, DIO
Si5351 si5351;

void setup()
{
  // Set up frequency and radix switches
  pinMode(rotAPin, INPUT);
  pinMode(rotBPin, INPUT);
  pinMode(pushPin, INPUT);
  pinMode(brightnessPin, INPUT);
  pinMode(gnd, OUTPUT);
  pinMode(tunespeedLED, OUTPUT);
  pinMode(vcc, OUTPUT);
  pinMode(KeyInput, INPUT);
  pinMode(PTTOutput, OUTPUT);

  // Set up pull-up resistors on inputs
  digitalWrite(rotAPin, HIGH);
  digitalWrite(rotBPin, HIGH);
  digitalWrite(pushPin, HIGH);
  digitalWrite(brightnessPin, HIGH);
  digitalWrite(gnd, LOW);
  digitalWrite(vcc, HIGH);
  digitalWrite(tunespeedLED, LOW);
  digitalWrite(KeyInput, HIGH);
  digitalWrite(PTTOutput, LOW);

  // Set up interrupt pins
  attachInterrupt(digitalPinToInterrupt(rotAPin), ISRrotAChange, CHANGE);
  attachInterrupt(digitalPinToInterrupt(rotBPin), ISRrotBChange, CHANGE);

  // Initialize the display
  display.setBrightness(Brightness, true);
  UpdateDisplay();
  delay(1000);

  // Initialize the DDS
  si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0);
  si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);
  si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_8MA);
  si5351.drive_strength(SI5351_CLK1, SI5351_DRIVE_8MA);
  si5351.drive_strength(SI5351_CLK2, SI5351_DRIVE_8MA);
  si5351.set_freq(((8999300 + freq) * 100ULL), SI5351_PLL_FIXED, SI5351_CLK0);
  si5351.set_freq((LSB_BFO_freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK2);
}


void loop()
{
  //LowPower.idle(SLEEP_60MS, ADC_OFF, TIMER2_OFF, TIMER1_OFF, TIMER0_OFF, SPI_OFF, USART0_OFF, TWI_OFF);
  LowPower.idle(SLEEP_60MS, ADC_OFF, TIMER2_OFF, TIMER1_OFF, TIMER0_ON, SPI_OFF, USART0_OFF, TWI_OFF);

  if (digitalRead(KeyInput) == LOW)
  {
    si5351.output_enable(SI5351_CLK1, 1);
    SendFrequency();
  }

  if (digitalRead(KeyInput) == HIGH)
  {
    si5351.output_enable(SI5351_CLK1, 0);
  }

  currentfreq = getfreq();                // Interrupt safe method to get the current frequency

  if (currentfreq != oldfreq)
  {
    UpdateDisplay();
    SendFrequency();
    oldfreq = currentfreq;
  }

  if (digitalRead(brightnessPin) == LOW)
  {
    Brightness--;
    display.setBrightness(Brightness, true);
    if (Brightness == -1)
    {
      display.setBrightness(0, false);
      digitalWrite(tunespeedLED, LOW);
      batterySave = 1;
    }
    if (Brightness == -2)
    {
      Brightness = 3;
      batterySave = 0;
    }
    UpdateDisplay();
    delay(500);
  }

  if ((radix == 100) && (batterySave == 0))
    digitalWrite(tunespeedLED, HIGH);

  if (radix == 1000)
    digitalWrite(tunespeedLED, LOW);
}


void wakeUp()
{
  // Just a handler for the sleep pin interrupt.
}


long getfreq()
{
  long temp_freq;
  cli();
  temp_freq = freq;
  sei();
  return temp_freq;
}


// Interrupt routines
void ISRrotAChange()
{
  if (digitalRead(rotAPin))
  {
    rotAval = 1;
    UpdateRot();
  }
  else
  {
    rotAval = 0;
    UpdateRot();
  }
}


void ISRrotBChange()
{
  if (digitalRead(rotBPin))
  {
    rotBval = 1;
    UpdateRot();
  }
  else
  {
    rotBval = 0;
    UpdateRot();
  }
}


void UpdateRot()
{
  switch (rotState)
  {

    case 0:                                         // Idle state, look for direction
      if (!rotBval)
        rotState = 1;                               // CW 1
      if (!rotAval)
        rotState = 11;                              // CCW 1
      break;

    case 1:                                         // CW, wait for A low while B is low
      if (!rotBval)
      {
        if (!rotAval)
        {
          // either increment radixindex or freq
          if (digitalRead(pushPin) == LOW)
          {
            if (radix == 1000)
              radix = 100;
            else if (radix == 100)
              radix = 1000;
          }
          else
          {
            freq = (freq + radix);
            if (freq > bandEnd)
              freq = bandEnd;
          }
          rotState = 2;                             // CW 2
        }
      }
      else if (rotAval)
        rotState = 0;                             // It was just a glitch on B, go back to start
      break;

    case 2:                                         // CW, wait for B high
      if (rotBval)
        rotState = 3;                               // CW 3
      break;

    case 3:                                         // CW, wait for A high
      if (rotAval)
        rotState = 0;                               // back to idle (detent) state
      break;

    case 11:                                        // CCW, wait for B low while A is low
      if (!rotAval)
      {
        if (!rotBval)
        {
          // either decrement radixindex or freq
          if (digitalRead(pushPin) == LOW)
          {
            if (radix == 100)
              radix = 1000;
            else if (radix == 1000)
              radix = 100;
          }
          else
          {
            freq = (freq - radix);
            if (freq < bandStart)
              freq = bandStart;
          }
          rotState = 12;                            // CCW 2
        }
      }
      else if (rotBval)
        rotState = 0;                             // It was just a glitch on A, go back to start
      break;

    case 12:                                        // CCW, wait for A high
      if (rotAval)
        rotState = 13;                              // CCW 3
      break;

    case 13:                                        // CCW, wait for B high
      if (rotBval)
        rotState = 0;                               // back to idle (detent) state
      break;
  }
}


void UpdateDisplay()
{
  TensMHz = freq / 10000000;                                // TensMHz = 12345678 / 10000000 = 1
  remainder = freq - (TensMHz * 10000000);                  // remainder = 12345678 - 10000000 = 2345678
  OnesMHz = remainder / 1000000;                            // OnesMhz = 2345678 / 1000000 = 2
  remainder = remainder - (OnesMHz * 1000000);              // remainder = 2345678 - (2 * 1000000) = 345678
  HundredskHz = remainder / 100000;                         // HundredskHz = 345678 / 100000 = 3
  remainder = remainder - (HundredskHz * 100000);           // remainder = 345678 - (3 * 100000) = 45678
  TenskHz = remainder / 10000;                              // TenskHz = 45678 / 10000 = 4
  remainder = remainder - (TenskHz * 10000);                // remainder = 45678 - (4 * 10000) = 5678
  OneskHz = remainder / 1000;                               // OneskHz = 5678 / 1000 = 5
  remainder = remainder - (OneskHz * 1000);                 // remainder = 5678 - (5 * 1000) = 678
  HundredsHz = remainder / 100;                             // HundredsHz = 678 / 100 = 6
  remainder = remainder - (HundredsHz * 100);               // remainder = 678 - (6 * 100) = 78
  TensHz = remainder / 10;                                  // TensHz = 78 / 10 = 7
  remainder = remainder - (TensHz * 10);                    // remainder = 78 - (7 * 10) = 8
  OnesHz = remainder;                                       // OnesHz = 8

  display.showNumberDec(((1000 * HundredskHz) + ( 100 * TenskHz) + (10 * OneskHz) + HundredsHz), true);
}


void SendFrequency()
{
  // PA TX Drive
 si5351.set_freq((freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK1);

  // VFO
  //si5351.set_freq((freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK0);
  si5351.set_freq(((8999300 + freq) * 100ULL), SI5351_PLL_FIXED, SI5351_CLK0);


  // BFO
  si5351.set_freq((LSB_BFO_freq * 100ULL), SI5351_PLL_FIXED, SI5351_CLK2);
}