Published October 8, 2022 © GPL3+

DIY Arduino Due TEA5767 FM Radio

How to make a small FM Radio with oled display which all functions are controlled by a single rotary encoder.

IntermediateFull instructions provided4,138

Things used in this project

Hardware components

Arduino Due

tea5767 Radio module

LM4811 smd IC

Graphic OLED, 128 x 64 Pixels

Rotary Encoder with Push-Button

PAM8403 small D-Class Audio amplifier

Resistors, capacitors

Speaker: 0.25W, 8 ohms

Software apps and online services

Arduino IDE

Story

This time I will show you how to make a small FM Radio with oled display which all functions are controlled by a single rotary encoder. So far I have made several FM radios, but this is my first project with an Arduino Due board.

The Arduino Due is a microcontroller board based on the Atmel ARM Cortex-M3 CPU. It is the first Arduino board based on a 32-bit ARM core microcontroller.

It has 54 digital input/output pins of which 12 can be used as PWM outputs, 12 analog inputs, 4 UARTs, a 84 MHz clock, an USB OTG capable connection, 2 (digital to analog), 2 TWI, a power jack, an SPI header, a reset button and an erase button.

The Due is compatible with all Arduino shields that work at 3.3V. The project is taken from https://www.changpuak.ch/ where it is named "Wacharamod" in honor of Khwankeo Vajarodaya, and where you can find the original schematic diagrams and code. In the hardware section I have omitted some resistors and filter capacitors for simplicity.

Otherwise, the device is relatively simple to build and contains the following components:

- TEA5767 small Radio board which is the basis of the whole project

- Arduino Due microcontroller board

- SH1106 Oled display

- LM4811 Headphone Amplifier with Digital Volume Control

- PAM8403 small audio D-class amplifier board

- Speaker

- and Rotary encoder

The radio module and other parts are mounted on a separate PCB compatible with Arduino Due pins, in my case it's experimental, but you can make a professional PCB, the cheapest, fastest, and highest quality at PCBWay. How to order is very easy and you will get 10 Pcs PCB for $5 with very great PCB quality TG150-160. Also You can design your own Gerber files for this circuit and upload it on their site (www.pcbway.com) Generally, shipping of the orders takes only 3 to 5 days.

Since this is my first project with Arduino Due, let me briefly explain how to upload a sketch to this board. First, we go to the Tools tab, then the board manager and in the search field we write Due. Now we need to install Arduino SAM Boards, which in my case are installed. Exit the board manager, and go to Tools > Board > Arduino Arduino ARM (32-bits) Boards. The Arduino Due has two USB ports available. We choose Programming port wich is the default for uploading sketches and communicating with the Arduino. After that we select the appropriate com port and we can upload the given sketch.

And now let's see how the radio works in real conditions. Immediately after switching on, the start screen appears on the screen with a logo and information about the software version. After that, the frequency of the radio station that was previously set in the code appears. In my case it is 94.8 megahertz where we can hear the local radio station. Short presses of the encoder change the focus under the frequency numbers, and rotating changes the value of the digit. After a few clicks, the focus moves to the volume bar, and now we can change the sound intensity by rotating it. With a long press on the rotary encoder, the radio switches to SEEK mode and starts automatic station search.

Finally, the device is installed in a suitable box made of PVC plastic with thicknesses of 3mm and 5mm and coated with a colored self-adhesive tape.

Schematics

Code

Arduino code

/* ///////////////////////////////////////////////////////////////////// 
ARDUINO/Genuino DUE Sketch for "Wachara 1"
https://www.changpuak.ch/electronics/Arduino-Shield-WACHARA1.php
As Wachara 1 passed away already, we use a white display
"Wachara 1" was the callsign of H.E. Khwankeo Vajarodaya, 
*03.09.1928 †28.01.2017, my teacher for Siamese Culture and Art
Software Version 3.9, 
03.09.2019, Alexander Sse Frank, 
//////////////////////////////////////////////////////////////////////*/
 
 
// /////////////////////////////////////////////////////
// Includes
// /////////////////////////////////////////////////////
 
 
#include <Adafruit_GFX.h>
#include <Adafruit_SH1106.h>
 
// OLED 128x64 with SH1106 Controller
// from https://www.displaymodule.com/
// E.G. DM-OLED13-625
#define OLED_MOSI  10
#define OLED_CLK   9
#define OLED_DC    12
#define OLED_CS    13
#define OLED_RESET 11
Adafruit_SH1106 display(OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS);
 
#if (SH1106_LCDHEIGHT != 64)
#error("Height incorrect, please fix Adafruit_SH1106.h!");
#endif
 
 
int CURSOR = 2 ;
 
float RX_FREQ = 107.6 ;    // Radio Basilisk <3
// float freq = 102.50 ;   // Surf 102.5 FM Hua Hin
float freq = 94.8 ;       // KCS Radio Hua Hin
long int pll ;
 
int MAX_BAR_LENGTH = 45 ;
int MIN_BAR_LENGTH = 1 ;
float MULTI = 2.9 ;
 
// /////////////////////////////////////////////////////
// LM4811
// /////////////////////////////////////////////////////
int VolUpDownPin = A0 ;
int VolClkPin = A2 ;
int VolShutDownPin = A1 ;
 
int VOLUME = 0 ;
int SETVOL = 4 ;          
int VOLMIN = 0 ;
int VOLMAX = 15 ;     // 16 STEPS
 
// /////////////////////////////////////////////////////
// TEA 5767
// /////////////////////////////////////////////////////
const int BusMode = A5 ;
const int WriteRead = A4 ;
const int CursorX = 115 ;
const byte TEA5767_ADR = 0x60 ;
byte RAM[] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00} ;
float BandStart = 87.5 ;
float BandStop = 108.0 ;
int RX_CLK_PIN = 21 ;
int RX_DAT_PIN = 20 ;
// /////////////////////////////////////////////////////
// WRITE
// /////////////////////////////////////////////////////
int HLSI  = 1 ;   // High Side Injection
int MUTE = 0 ;    // L+R UNMUTED
int SM = 0 ;      // NOT IN SEARCH MODE
int SUD = 1 ;     // SEARCH UP
int SSL = 1 ;     // SEARCH STOP LEVEL = LOW ADC output = 5
int MS = 0 ;      // STEREO
int MR = 0 ;      // RIGHT CHANNEL UNMUTED
int ML = 0 ;      // LEFT CHANNEL UNMUTED
int BL = 0 ;      // BAND LIMITS EUROPE
int XTAL = 1 ;    // 32.768 kHz 
int SMUTE = 1 ;   // SOFT MUTE IS ON
int HCC = 0 ;     // HIGH CUT CONTROL IS OFF
int SNC = 1 ;     // STEREO NOISE CANCELLING IS ON
int DTC = 0 ;     //  de-emphasis time constant is 50 µs
// /////////////////////////////////////////////////////
// READ
// /////////////////////////////////////////////////////
int RF = 0 ;
int BLF = 0 ;
int Stereo = 0 ;
int RSSI = 0 ;
int IFCounts = 0 ;
 
 
volatile boolean SearchMode = false ;
 
 
 
// ////////////////////////////////////////////////////////////////////
// ROTARY ENCODER
// ////////////////////////////////////////////////////////////////////
 
const int KEY1 = 6 ;
const int KEY2 = 7 ;
const int KEY3 = 5 ;    // PRESSED
 
volatile boolean action = false ;
volatile boolean pressed = false ;
volatile boolean clockwise = false ;
volatile boolean rotation = false ;
 
unsigned int ShortLongPressTime = 600 ; // MILLISECONDS
// IF THE KNOB WAS PRESSED SHORTER, IT IS CONSIDERED "SHORT"
// IF THE KNOB WAS PRESSED LONGER, IT IS CONSIDERED "LONG"
boolean LongPress = false ;
 
void ISR_K1 (void)
{
  byte autre = digitalRead(KEY2) ;
  if (autre == 1) clockwise = true ;
  else clockwise = false ;
  action = true ;
  pressed = false ;
  rotation = true ;
}
 
void ISR_K2 (void)
{
  byte autre = digitalRead(KEY1) ;
  if (autre == 1) clockwise = true ;
  else clockwise = false ;
  action = true ;
  pressed = false ;
  rotation = true ;
}
 
void ISR_K3 (void)
{
  pressed = true ;
  action = true ;
  rotation = false ;
}
 
 
// ////////////////////////////////////////////////////////////////////
 
byte HIBYTE(unsigned int data) 
{
  return ((data & 0xFF00) >> 8) ;
}
 
// ////////////////////////////////////////////////////////////////////
 
byte LOBYTE(unsigned int data) 
{
  return (data & 0x00FF) ;
}
 
// ////////////////////////////////////////////////////////////////////
 
void VolumeUp(int HowMuch) 
{
  digitalWrite(VolUpDownPin, HIGH);
  for(int i=0; i < HowMuch; i++)
  {
    VOLUME += 1 ;
    digitalWrite(VolClkPin, HIGH);
    delay(100) ;
    digitalWrite(VolClkPin, LOW);
    delay(100) ;
    UpdateOLED() ;
  }
}
 
// ////////////////////////////////////////////////////////////////////
 
void VolumeDown(int HowMuch) 
{
  digitalWrite(VolUpDownPin, LOW);
  for(int i=0; i < HowMuch; i++)
  {
    digitalWrite(VolClkPin, HIGH);
    digitalWrite(VolClkPin, LOW);
  }
  VOLUME = 0 ;
  UpdateOLED() ;
}
// ////////////////////////////////////////////////////////////////////
 
void SET_VOLUME() 
{
  digitalWrite(VolUpDownPin, LOW);
  for(int i=0; i < 18; i++)
  {
    digitalWrite(VolClkPin, HIGH);
    digitalWrite(VolClkPin, LOW);
  }
  digitalWrite(VolUpDownPin, HIGH);
  for(int i=0; i < VOLUME; i++)
  {
    digitalWrite(VolClkPin, HIGH);
    digitalWrite(VolClkPin, LOW);
  }  
  UpdateOLED() ;
}
 
// ////////////////////////////////////////////////////////////////////
 
void VolumeMute() 
{
  digitalWrite(VolShutDownPin, HIGH);
}
 
// ////////////////////////////////////////////////////////////////////
 
void VolumeUnMute() 
{
  digitalWrite(VolShutDownPin, LOW);
}
 
// ////////////////////////////////////////////////////////////////////
 
void setup() 
{
  // TEA5767
  pinMode(BusMode, OUTPUT);
  digitalWrite(BusMode, HIGH);
  pinMode(RX_DAT_PIN, OUTPUT);
  digitalWrite(RX_DAT_PIN, LOW);
  pinMode(RX_CLK_PIN, OUTPUT);
  digitalWrite(RX_CLK_PIN, LOW);
  pinMode(WriteRead, OUTPUT);
  digitalWrite(WriteRead, HIGH);
 
  // LMX4811
  pinMode(VolUpDownPin, OUTPUT);
  digitalWrite(VolUpDownPin, LOW); // JUST TO HAVE A DEFINED LEVEL
  pinMode(VolClkPin, OUTPUT);
  digitalWrite(VolClkPin, LOW);
  pinMode(VolShutDownPin, OUTPUT);
  digitalWrite(VolShutDownPin, LOW); // SWITCH THAT THING ON
  // This shutdown function is activated by applying a logic high 
  // to the SHUTDOWN pin.
     
  Serial.begin(9600);    // SERIAL
  
  // INIT OLED  
  display.begin(SH1106_SWITCHCAPVCC);
   
  // SHOW STARTUP SCREEN
  display.clearDisplay();
  display.drawLine(0, 14, 128, 14, WHITE);
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,0); display.print("*****") ;
  display.setCursor(33,0); display.print(" MIRCEMK") ;
  display.setCursor(90,0); display.print("******") ;
  display.setTextSize(1);
  display.setCursor(0,21);
  display.println("A MULTIBAND RECEIVER");
  display.setCursor(0,33);
  display.println("WITH NXP's TEA5767");
  display.setCursor(0,45);
  display.println("IN MEMORIAM WACHARA 1");
  display.setCursor(0,57);
  display.println("BUILT 03.09.2019");
  display.display();
  delay(4999) ;
 
  VolumeDown(18) ; // YES, WE USE THE COMMODORE 1541 APPROACH HERE
   
  // FREQ_TEA5767(freq) ;
  HiLoOptimiser() ;
 
  delay(100) ;
 
  // FREQ_TEA5767(freq) ;
  HiLoOptimiser() ;
 
   
  Serial.println("TEA5767 RADIO, TYPE WACHARA 1");
  Serial.println("-----------------------------");  
  READ_TEA5767() ;
  Serial.println(RAM[0],HEX) ;   
  Serial.println(RAM[1],HEX) ;   
  Serial.println(RAM[2],HEX) ;   
  Serial.println(RAM[3],HEX) ;   
  Serial.println(RAM[4],HEX) ;   
  Serial.println("-----------------------------");
   
  VOLUME = SETVOL ;
  SET_VOLUME() ; 
 
  UpdateOLED() ;
  
  // ROTARY ENCODER
  pinMode(KEY1, INPUT_PULLUP) ;
  pinMode(KEY2, INPUT_PULLUP) ;
  pinMode(KEY3, INPUT_PULLUP) ;
 
  // INTERRUPTS ROTARY ENCODER
  attachInterrupt(digitalPinToInterrupt(KEY1), ISR_K1, RISING);   // ROT 
  attachInterrupt(digitalPinToInterrupt(KEY2), ISR_K2, FALLING);  // ROT
  attachInterrupt(digitalPinToInterrupt(KEY3), ISR_K3, FALLING);  // PRESS
   
  delay(3999);
 
  action = false ;
  pressed = false ;
  clockwise = false ;
  rotation = false ;
 
  // SCAN() ;
  freq = 94.80                                                                                                                                                                                               ;
  HiLoOptimiser() ;
 
 
}
 
// ////////////////////////////////////////////////////////////////////
 
void BAR(int x, int y, int value) 
{
  if (value > MAX_BAR_LENGTH) value = MAX_BAR_LENGTH ;
  if (value < MIN_BAR_LENGTH) value = MIN_BAR_LENGTH ;
  display.drawRect(x, y, MAX_BAR_LENGTH, 7, WHITE);
  display.fillRect(x, y, value, 7, WHITE);
}
 
 
// ////////////////////////////////////////////////////////////////////
 
 
void UpdateOLED() 
{
  display.clearDisplay();
  display.drawLine(0, 11, 128, 11, WHITE);
  display.drawLine(0, 32, 128, 32, WHITE);
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,0); display.print("*****") ;
  display.setCursor(33,0); display.print(" MIRCEMK") ;
  display.setCursor(90,0); display.print("******") ;
  display.setTextSize(2);
  display.setCursor(0,15);
  if(!SearchMode)
  {
  if (freq < 100.0) display.print(" ");
  if (freq < 10.0) display.print(" ");
  display.print(freq,3);
  // display.print("0");
  // CURSOR 
  if (CURSOR == 0) { display.setCursor( 0,19); display.print("_") ; }
  if (CURSOR == 1) { display.setCursor(12,19); display.print("_") ; }
  if (CURSOR == 2) { display.setCursor(24,19); display.print("_") ; }
  if (CURSOR == 3) { display.setCursor(48,19); display.print("_") ; }
  if (CURSOR == 4) { display.setCursor(60,19); display.print("_") ; }
  display.setCursor(92,15);
  display.print("MHz");
  }
  if(SearchMode)
  {
  display.setCursor(10,15);
  display.print("SEARCHING");
  }
  display.setTextSize(1);
  display.setCursor(0,37);
  display.print("RSSI "); 
  if(HLSI == 1) display.print("+"); 
  if(HLSI == 0) display.print("-");
  BAR(40, 37, (RSSI*3) ) ;  
  display.setCursor(91,37);
  if (Stereo == 1) display.print("STEREO");
  if (Stereo == 0) display.print("  MONO");  
  display.setCursor(0,47);
  display.print("VOLUME "); BAR(40, 47, (VOLUME*3) ) ; 
  if (CURSOR == 5) { display.setCursor(91,47); display.print("<<<") ; }
  display.setCursor(0,57);
  display.print("PRESS LONG TO SEARCH"); 
   
  display.display();
}
 
 
void ButtonPressed()
{
  // //////////////////////////////////////////////////
  // WAS IT PRESSED LONG >>> START SEARCH UP
  // //////////////////////////////////////////////////
  LongPress = false ;
  delay(ShortLongPressTime) ;
  if(digitalRead(KEY3) == 0) LongPress = true ;
   
  if(LongPress)
  {  
  // //////////////////////////////////////////////////
  // SEARCH UPWARDS
  // //////////////////////////////////////////////////
  Serial.println("PRESSED LONG") ; 
  SearchUP() ;
  pressed = false ;
   
   
  }
  // //////////////////////////////////////////////////
  // WAS IT PRESSED SHORT >>> MOVE CURSOR RIGHT
  // //////////////////////////////////////////////////
  if(!LongPress)
  {  
  Serial.println("PRESSED SHORT") ; 
  CURSOR += 1 ;
  if(CURSOR > 5) CURSOR = 2 ;
  }  
  pressed = false ;
}
 
 
void ButtonRotated()
{
  // //////////////////////////////////////////////////
  // WAS IT ROTATED RIGHT >>> INCREASE
  // //////////////////////////////////////////////////
  if(clockwise)
  {
  // Serial.println("CW") ; 
  switch(CURSOR)
  {
    case 2: 
      freq = freq - 1.0 ; 
      if(freq < BandStart) freq = BandStart ;
      HiLoOptimiser() ;
      delay(10) ;
      READ_TEA5767() ;  // RSSI
       break ;
    case 3: 
      freq = freq - 0.1 ; 
      if(freq < BandStart) freq = BandStart ;
      HiLoOptimiser() ;
      delay(10) ;
      READ_TEA5767() ;  // RSSI
      break ;
    case 4: 
      freq = freq - 0.01 ;
      if(freq < BandStart) freq = BandStart ; 
      HiLoOptimiser() ;
      delay(10) ;
      READ_TEA5767() ;  // RSSI
      break ;
    case 5: 
      VOLUME = VOLUME - 1 ;
      if(VOLUME < VOLMIN ) VOLUME = VOLMIN ;
      SET_VOLUME() ;
      break ;
  }
  rotation = false ;
  UpdateOLED() ; 
  }
 
   
  // //////////////////////////////////////////////////
  // WAS IT ROTATED LEFT >>> DECREASE
  // //////////////////////////////////////////////////
  if(!clockwise)
  {
  // Serial.println("CCW") ; 
  switch(CURSOR)
  {
    case 2: 
      freq = freq + 1.0 ; 
      if(freq > BandStop) freq = BandStop ;
      HiLoOptimiser() ;
      delay(10) ;
      READ_TEA5767() ;  // RSSI
      break ;
    case 3: 
      freq = freq + 0.1 ; 
      if(freq > BandStop) freq = BandStop ;
      HiLoOptimiser() ;
      delay(10) ;
      READ_TEA5767() ;  // RSSI
      break ;
    case 4: 
      freq = freq + 0.01 ;
      if(freq > BandStop) freq = BandStop ; 
      HiLoOptimiser() ;
      delay(10) ;
      READ_TEA5767() ;  // RSSI
      break ;
    case 5: 
      VOLUME = VOLUME + 1 ;
      if(VOLUME > VOLMAX ) VOLUME = VOLMAX ;
      SET_VOLUME() ;
      break ;
  }
  rotation = false ;
  UpdateOLED() ; 
  }
}
 
 
void READ_TEA5767()
{  
  pinMode(RX_DAT_PIN, INPUT);
  digitalWrite(RX_CLK_PIN, HIGH);
  delay(1) ;
  digitalWrite(WriteRead, HIGH); 
  delay(1) ;
  digitalWrite(WriteRead, LOW); 
  delay(1) ;
  RAM[0] = shiftIn(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST) ;
  RAM[1] = shiftIn(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST) ;
  RAM[2] = shiftIn(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST) ;
  RAM[3] = shiftIn(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST) ;
  RAM[4] = shiftIn(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST) ;
  Stereo = (RAM[2] & 0x80) >> 7 ;
  RSSI = (RAM[3] & 0xF0) >> 4 ;
  RF = (RAM[0] & 0x80) >> 7 ;
  BLF = (RAM[0] & 0x40) >> 6 ;
  IFCounts = RAM[2] & 0x7F ;
}
 
 
void WRITE_TEA5767()
{
  pinMode(RX_DAT_PIN, OUTPUT);
  digitalWrite(RX_CLK_PIN, LOW); delay(1) ;
  digitalWrite(WriteRead, LOW); delay(1) ;
  digitalWrite(WriteRead, HIGH); delay(1) ;
  if(HLSI == 1) pll=(int)(((freq+0.225)*122.0703125)+0.5);
  if(HLSI == 0) pll=(int)(((freq-0.225)*122.0703125)+0.5);
  RAM[5] = HIBYTE(pll) | (MUTE<<7) | (SM<<6) ; 
  RAM[6] = LOBYTE(pll) ; 
  RAM[7] = (SUD<<7)|(SSL<<5)|(HLSI<<4)|(MS<<3)|(MR<<2)|(ML<<1) ; 
  RAM[8] = (BL<<5)|(XTAL<<4)|(SMUTE<<3)|(HCC<<2)|(SNC<<1);
  RAM[9] = DTC<<6 ;  
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[5]);
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[6]);
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[7]);
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[8]);
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[9]);
}
 
 
void HiLoOptimiser()
{
  int RSSIHigh = 0 ;
  int RSSILow = 0 ;
  float Frequency = freq ;
  SM = 0 ;    // NOT IN SEARCH MODE
  VolumeMute() ;
  if (Frequency > BandStop) Frequency = BandStop ;
  if (Frequency < BandStart) Frequency = BandStart ;
  // //////////////////////////////////////////////////
  // RSSIHigh is at freq + 450 kHz
  // //////////////////////////////////////////////////
  freq = Frequency + 0.225 ;
  HLSI = 1 ;
  WRITE_TEA5767() ; 
  delay(10) ;
  READ_TEA5767() ;
  RSSIHigh = RSSI ;
  // //////////////////////////////////////////////////
  // RSSILow is at freq - 450 kHz
  // //////////////////////////////////////////////////
  HLSI = 0 ;
  freq = Frequency - 0.225 ;
  WRITE_TEA5767() ; 
  delay(10) ;
  READ_TEA5767() ;
  RSSILow = RSSI ;
  // //////////////////////////////////////////////////
  // EVALUATION SEE APPLICATION NOTE PAGE 27
  // //////////////////////////////////////////////////
  if(RSSIHigh < RSSILow)
  {
    // OPTIMUM SETTING IS HIGH SIDE INJECTION
    HLSI = 1 ;
    freq = Frequency ;
    WRITE_TEA5767() ; 
  }
  else
  {
    // OPTIMUM SETTING IS LOW SIDE INJECTION
    HLSI = 0 ; 
    freq = Frequency ;
    WRITE_TEA5767() ;    
  }
  delay(27);
  READ_TEA5767() ;
  VolumeUnMute() ;
  UpdateOLED() ;
}
 
 
void SCAN()
{
  freq = BandStart ;
  while(freq <= BandStop)
  {
    HiLoOptimiser() ;
    if(RSSI >=4)
    {
    if(freq <100.0) Serial.print(" ");
    Serial.print(freq,3); Serial.print(" RSSI: ");
    Serial.print(RSSI,DEC);
    Serial.print(" IFC: ");
    Serial.println(IFCounts,DEC);
    }
    freq += 0.098304 ;
    delay(30);
  } 
}
 
void SearchUP()
{
  Serial.println("SEARCHING ...");
  SearchMode = true ;
  UpdateOLED() ;
  int RSSILAST = 0 ;
  int RSSICURR = 0 ;
  int RSSINEXT = 0 ;
  boolean STOPSEARCH = false ;
  float Frequency = freq ;
  while(!STOPSEARCH)
  {
    freq += 0.098304 ;
    HiLoOptimiser() ;
    if(RSSI >=4)
    {
    if(freq <100.0) Serial.print(" ");
    Serial.print(freq,3); 
    Serial.print(" RSSI: ");
    if(RSSI < 10) Serial.print(" ");
    Serial.print(RSSI,DEC);
    Serial.print(" IFC: ");
    Serial.println(IFCounts,DEC);
    if((IFCounts > 56) && (IFCounts < 71))
      {
        STOPSEARCH = true ;
        SearchMode = false ;
        Serial.println("FOUND.");
      }
    } // END RSSI-IF
    if(freq >= BandStop)
    {
      freq = BandStart ;
      STOPSEARCH = true ;
      SearchMode = false ;
    } // END BANDSTOP
    delay(100);
    } // END WHILE 
  SearchMode = false ;
  UpdateOLED() ;
}
 
 
// ///////////////////////////////////////////////////////////// 
// UNUSED FUNCTIONS
// ///////////////////////////////////////////////////////////// 
 
void FREQ_TEA5767(float FRQ)
{
  int aux ;
  if (FRQ > BandStop) FRQ = BandStop ;
  if (FRQ < BandStart) FRQ = BandStart ;
  pll = (int)((( FRQ + 0.225 ) * 122.0703125 ) + 0.5 );
  RAM[5] = HIBYTE(pll) ;
  RAM[6] = LOBYTE(pll) ;
  // Search Up, Low Volume, High Side Injection, Stereo, No Mute
  RAM[7] = 0xC0; 
  // EU Band, Clock 32768, Stero Noise Cancelling On
  RAM[8] = 0x12 ; 
  RAM[9] = 0x00 ; // De-Emphasis Time Constant is 50 µs
  pinMode(RX_DAT_PIN, OUTPUT);
  delay(1) ;
  digitalWrite(WriteRead, LOW); 
  delay(1) ;
  digitalWrite(WriteRead, HIGH); 
  delay(1) ;
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[5]);
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[6]);
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[7]);
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[8]);  
  shiftOut(RX_DAT_PIN, RX_CLK_PIN, MSBFIRST, RAM[9]);
}
 
 
// ///////////////////////////////////////////////////////////// 
 
void loop() 
{
  if (action)
  {
    if(pressed) ButtonPressed() ;
    if(rotation) ButtonRotated() ;
    action = false ;
    UpdateOLED() ;
  }
  delay(9) ;
}
 
// ///////////////////////////////////////////////////////////// 
// END OF FILE
// /////////////////////////////////////////////////////////////

DIY Arduino Due TEA5767 FM Radio

Things used in this project

Hardware components

Software apps and online services

Story

Custom parts and enclosures

Speaker grill Stl file

Schematics

Schematic1

Schematic2

Code

Arduino code

Credits

Mirko Pavleski

Comments

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DIY Arduino Due TEA5767 FM Radio

DIY Arduino Due TEA5767 FM Radio

Things used in this project

Hardware components

Software apps and online services

Story

Custom parts and enclosures

Speaker grill Stl file

Schematics

Schematic1

Schematic2

Code

Arduino code

Credits

Mirko Pavleski

Comments

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