Simple FM Radio Receiver Using Arduino And RDA5807M

Today we belong to a new world, and different kinds of modern gadgets are built every day. Almost everyone has mobile phones to listen to their favourite music, news, podcasts, etc. But a few years back, we were not as developed as the present situation. All are depending on local FM Radios to listen to every day’s latest news and songs. Slowly these Radios are losing their popularity, but when the internet is down in your locality, radios take place in a vital role to transmit information to the listeners. Radio signals are always present in the atmosphere (which are generally broadcast from radio stations), and all we need to receive this FM audio signal by an FM receiver circuit. In previous projects, we previously built an FM Transmitter circuit, please check it out.

In this project, we are going to design an Arduino based FM Radio Receiver circuit using the RDA5807 FM receiver module. We will use the RDA5807 FM Receiver module with Arduino Nano and play the desired tuned FM radio station which can be displayed also in the I2C OLED display. To boost the audio volume, we will also add a PAM8403 audio amplifier module along with the circuit. So, let’s do this.

Table of Contents

Circuit Diagram

Components Required

Arduino Nano
RDA5807M (V.1/V.2) FM Receiver Module
I2C OLED Display
10K Resistor (x3)
Connection Wire
Antenna
Breadboard
9V Battery

What is an RDA5807M FM Frequency Receiver?

The RDA5807M is a simple stereo radio frequency receiver IC that can support worldwide FM bands from 50 MHz to 115 MHz. It contains a fully integrated synthesizer, intermediate frequency (IF) selectivity, RDS/RBDS, and an MPX decoder.

This IC has a powerful low intermediate frequency digital audio processor, which generally means that you can directly listen to your favourite station via headphones through a 3.5mm audio jack. If you want a louder sound, connect this circuit output signal to an amplifier circuit. I am using the PAM8403 stereo audio amplifier module here for demonstration purposes.

PCB Design

After designing the schematic diagram of the FM Radio, the assembled components and wiring are too clumsy and looked very unprofessional. In fact, the wiring also has a chance of loose connection. To give it a clean and professional look and also to compress the size, I decided to build its PCB prototype using EasyEDA software as it is so simple to use. Now come to the main part, where we need to order our PCB prototype. I always prefer PCBWay for their quality assurance, fastest delivery and also for 24/7 customer support.

Download Gerber File

PCB View

Why I Choose PCBWay as My First Preference?

I’ve done several runs with PCBWay and am happy with the results, it’s good quality. It is one of the most experienced PCB manufacturing companies based in China with an experience of more than a decade in the field of PCB prototype and fabrication. PCBWay has always been committed to technological innovation and meeting the needs of their customers from different industries in terms of quality, delivery, cost-effectiveness and any other demanding requests. The etching, solder mask, and hole sizes are all done well and that is what matters to me. It takes a few hours for a design to get approved and then a couple of days to finish and ship.

With more than a decade in the field of PCB prototypes and fabrication, PCBWay has proved its assurance from time to time. They always look at the customer’s needs from different regions in terms of quality, on-time delivery, cost-effectiveness and any other demanding requests.

These PCBs were manufactured by PCBWay and the finish quality really impressive, especially with the gold finish path. If you want to finish your product faster you could also ask PCBWay to make a panelized order where you receive multiple PCBs in a single panel. With this, you will also receive SMT Stencil from PCBWay, saving you time and effort. All the orders are high quality and could select a lot of settings such as thickness, flexible PCB, the colour of the solder masks, the number of layers, material, surface finish and more.

How to Order PCB from PCBWay?

Working Principle of FM Radio Circuit Using Arduino

The radio stations convert electrical signals to radios signals, and these signals need to be modulated before transmitting through the antenna. There are two methods in which a signal can be modulated namely AM and FM. As the name implies, amplitude modulation (AM) modulates amplitude before transmitting a signal whereas, in frequency modulation (FM), the frequency of the signal is modulated before transmitting through the antenna. Radio stations use frequency modulation to modulate the signal and then transmit the data.

Now, all we need to build is a FM receiver that can receive the signals and tuned to certain frequencies. After that, it demodulates and converts these electrical signals to audio signals.

Arduino Code

To compile the Arduino code, we need to install Adafruit_SSD1306, RDA5807M libraries.

#include <EEPROM.h>
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_GFX.h>
//#include <TFT_ILI9163C.h>
#include <Adafruit_SSD1306.h>
#include <RDA5807M.h>
#include <RDSParser.h>
#include <radio.h>
//extern const uint8_t icon_radio[];
//extern const uint8_t icon_volume[];
RDA5807M radio;    ///< Create an instance of a RDA5807 chip radio
#define DEBUG 0
#define OLED_RESET 4
Adafruit_SSD1306 tft(OLED_RESET);
RDSParser rds;
enum RADIO_STATE {
  STATE_PARSECOMMAND, ///< waiting for a new command character.
  STATE_PARSEINT,     ///< waiting for digits for the parameter.
  STATE_EXEC          ///< executing the command.
};
RADIO_STATE state; ///< The state variable is used for parsing input characters.
const int entrada = A0;
int entradaV = 0;
int menu;
#define MAXmenu  3
int menux;
#define MAXmenux  3
static char* menuS[] = {" ", "MANUAL TUNE", "VOLUME     ", "AUTO TUNE", "INFO        "};
int volumen, volumenOld = 7;
int frecuencia, frecuenciaOld;
int signal_level;
unsigned int z, z1;
byte xfrecu, xfrecuOld;
unsigned int estado[6];
unsigned long time, time1, time2, time3;
char buffer[30];
unsigned int RDS[4];
char seg_RDS[8];
char seg_RDS1[64];
char indexRDS1;
char hora, minuto, grupo, versio;
unsigned long julian;
int mezcla;
//radio.debugEnable();
void RDS_process(uint16_t block1, uint16_t block2, uint16_t block3, uint16_t block4) {
  rds.processData(block1, block2, block3, block4);
}
void setup()
{
  Wire.begin();
  //Serial.begin(9600);
  Serial.begin(57600);
  tft.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  radio.init();
  radio.debugEnable();
  tft.display();
  delay(20);
  // Clear the buffer.
  tft.clearDisplay();
  // read value of last frequency
  frecuencia = EEPROM.read(201);
  volumen = EEPROM.read(202);
  if (volumen < 0) volumen = 0;
  if (volumen > 15) volumen = 15;
  if (frecuencia < 0) frecuencia = 0;
  if (frecuencia > 210) frecuencia = 210;
  tft.setRotation(0);
  tft.setTextColor(WHITE);
  tft.setCursor(95, 0);
  // tft.print("Nivel semnal :");
  tft.print(signal_level); tft.display();
  tft.print("/15 ");
  // draw an antenna
  tft.drawLine(103, 9, 103, 13, WHITE);
  tft.drawCircle(103, 9, 2, WHITE);
  WriteReg(0x02, 0xC00d); // write 0xC00d into Reg.2 ( soft reset, enable,RDS, )
  WriteReg(0x05, 0x84d8); // write ,0x84d8 into Reg.3
  time3 = time2 = time1 = time = millis();
  menu = 3;
  canal(frecuencia);
  // clearRDS;
  state = STATE_PARSECOMMAND;
  // setup the information chain for RDS data.
  radio.attachReceiveRDS(RDS_process);
  rds.attachServicenNameCallback(tftServiceName);
  //  rds.attachTimeCallback(tftTime);
}
void tftServiceName(char *name)
{
  size_t len = strlen(name);
  tft.setCursor(0, 25);
  tft.setTextSize(1.5);
  tft.setTextColor(WHITE, BLACK);
  tft.print(name); tft.setTextColor(WHITE, BLACK);  tft.display();
  while (len < 8) {
    tft.print(' '); tft.setTextColor(WHITE, BLACK); tft.display();
    len++;
  } // while
} // tftServiceName()
void loop() {
  int newPos;
  unsigned long now = millis();
  // static unsigned long nextFreqTime = 0;
  static unsigned long nextRadioInfoTime = 0;
  char c;
  entradaV = analogRead(entrada);
#if DEBUG
  Serial.print("sensor = " );  Serial.println(entradaV); delay(50);
#endif
  // Boton menu
  if (entradaV > 500 && entradaV < 524)
  {
    Serial.print(entradaV);
    menu++;
    if (menu > MAXmenu)menu = 1;
    Visualizar();
#if DEBUG
    Serial.print("menu = " );  Serial.println(menu);
#endif
    while (1020 > analogRead(entrada))delay(5);
  }
  // Boton derecho
  if ( entradaV < 50)
  {
    Serial.print(entradaV);
    menux++;
    if (menux > MAXmenux)menux = MAXmenux;
#if DEBUG
    Serial.print("menux = " );  Serial.println(menux);
#endif
    switch (menu)
    {
      case 1:
        frecuencia++;
        if (frecuencia > 210)frecuencia = 210; // верхняя граница частот
        delay(130);
        break;
      case 2:
        volumen++;
        if (volumen > 15)volumen = 15;
        while (1020 > analogRead(entrada))delay(5);
        break;
      case 3:
        busqueda(0);
        while (1020 > analogRead(entrada))delay(5);
        break;
      case 4:
        // LcdClear();
        tft.clearDisplay();
        // visualPI();
        delay(3000);
        // LcdClear();
        tft.clearDisplay();
        frecuenciaOld = -1;
        break;
    }
  }
  // Boton izquierdo
  if ( entradaV < 700 && entradaV > 660)
    //if( entradaV<700 && entradaV>660)
  {
    Serial.print(entradaV);
    menux--;
    if (menux < 1)menux = 1;
#if DEBUG
    Serial.print("menux = " );  Serial.println(menux);
#endif
    switch (menu)
    {
      case 1:
        frecuencia--;
        if (frecuencia < 0)frecuencia = 0;
        delay(130);
        break;
      case 2:
        volumen--;
        if (volumen < 0)volumen = 0;
        while (1020 > analogRead(entrada))delay(5);
        break;
      case 3:
        busqueda(1);
        while (1020 > analogRead(entrada))delay(5);
        break;
      case 4:
        // LcdClear();
        tft.clearDisplay();
        //tft.print(frecuencia);
        //visualPTY();
        delay(3000);
        // LcdClear();
        tft.clearDisplay();
        frecuenciaOld = -1;
        break;
    }
  }
  if ( millis() - time2 > 50)
  {
    ReadEstado();
    time1 = millis();
    //RDS
    if ((estado[0] & 0x8000) != 0) {
      get_RDS();
    }
  }
  if ( millis() - time3 > 500)
  {
    time3 = millis();
    Visualizar();
  }
  if ( frecuencia != frecuenciaOld)
  {
    frecuenciaOld = frecuencia;
    z = 870 + frecuencia;
    EEPROM.write(201, frecuencia);
#if DEBUG
    Serial.print("Frecuencia = " );  Serial.println(frecuencia);
#endif
    sprintf(buffer, "%04d ", z);
    // tft.drawBitmap(80, 2,  icon_volume, 24, 10, WHITE);
    //tft.display();
    tft.setCursor(0, 0);
    tft.setTextSize(2);
    tft.setTextColor(WHITE, BLACK);
    for (z = 0; z < 5; z++)
    {
      if (z == 0) {
        if (frecuencia < 130) tft.print(" ");
        else tft.print(buffer[0]); tft.setTextColor(WHITE, BLACK);
      }
      if (z == 3)  tft.print(","); tft.setTextColor(WHITE, BLACK);
      if (z > 0) tft.print(buffer[z]); tft.setTextColor(WHITE, BLACK);
    }
    //   LcdString("MHz");
    tft.setCursor(65, 5);
    tft.setTextSize(1);
    tft.setTextColor(WHITE, BLACK);
    tft.print("MHz");
    tft.setTextColor(WHITE, BLACK);
    tft.display();
    canal(frecuencia);
    //  clearRDS();
  }
  //Cambio de volumen
  if (volumen != volumenOld)
  {
    volumenOld = volumen;
    sprintf(buffer, "Volum %02d", volumen); tft.setCursor(62, 25); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print(buffer); tft.print(" ");
    tft.display(); tft.print("/15");
    WriteReg(5, 0x84D0 | volumen);
    EEPROM.write(202, volumen);
  }
  // check for RDS data
  radio.checkRDS();
}
void busqueda(byte direc)
{
  byte i;
  if (!direc) WriteReg(0x02, 0xC30d); else  WriteReg(0x02, 0xC10d);
  for (i = 0; i < 10; i++)
  {
    delay(200);
    ReadEstado();
    if (estado[0] & 0x4000)
    {
      //Serial.println("Emisora encontrada");
      frecuencia = estado[0] & 0x03ff;
      break;
    }
  }
}
void Visualizar(void)
{
  //  tft.setCursor(3, 13); tft.setTextSize(2); tft.setTextColor(WHITE, BLACK); tft.print("FM");
  // tft.setCursor(27, 20); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print("RDA5807-");
  sprintf(buffer, "%s", menuS[menu]); tft.setCursor(5, 17); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print(buffer);
  //Detectar se&#241;al stereo
  tft.display();
  tft.setCursor(85, 15);
  tft.setTextColor(BLACK, WHITE);
  if ((estado[0] & 0x0400) == 0)  tft.print("");   else     tft.setTextColor(BLACK, WHITE); tft.print("Stereo");  tft.setTextColor(BLACK, WHITE);
  tft.display();
  //Se&#241;al
  //  z=estado[1]>>10; sprintf(buffer,"S-%02d",z); tft.setCursor(58,0); tft.setTextColor(WHITE, BLACK); tft.print(buffer); tft.setCursor(25,0);tft.setTextColor(WHITE, BLACK);tft.print("Canal");
  sprintf(buffer, "Volum %02d", volumen); tft.setCursor(62, 25); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print(buffer); //DUBLARE AFISARE VOLUM
  tft.display(); tft.print("/15");
  frecuencia = estado[0] & 0x03ff;
}
void canal( int canal)
{
  byte numeroH, numeroL;
  numeroH =  canal >> 2;
  numeroL = ((canal & 3) << 6 | 0x10);
  Wire.beginTransmission(0x11);
  Wire.write(0x03);
  Wire.write(numeroH);                     // write frequency into bits 15:6, set tune bit
  Wire.write(numeroL);
  Wire.endTransmission();
}
void WriteReg(byte reg, unsigned int valor)
{
  Wire.beginTransmission(0x11);
  Wire.write(reg); Wire.write(valor >> 8); Wire.write(valor & 0xFF);
  Wire.endTransmission();
  //delay(50);
}
//RDA5807_adrs=0x10;
// I2C-Address RDA Chip for sequential  Access
int ReadEstado()
{
  Wire.requestFrom(0x10, 12);
  for (int i = 0; i < 6; i++) {
    estado[i] = 256 * Wire.read () + Wire.read();
  }
  Wire.endTransmission();
}
//READ RDS  Direccion 0x11 for random access
void ReadW()
{
  // Wire.beginTransmission(0x11);            // Device 0x11 for random access
  // Wire.write(0x0C);                                // Start at Register 0x0C
  // Wire.endTransmission(0);                         // restart condition
  // Wire.requestFrom(0x11,8, 1);       // Retransmit device address with READ, followed by 8 bytes
  // for (int i=0; i<4; i++) {RDS[i]=256*Wire.read()+Wire.read();}        // Read Data into Array of Unsigned Ints
  // Wire.endTransmission();
}
void get_RDS()
{
  /* int i;
    ReadW();
    grupo=(RDS[1]>>12)&0xf;
       if(RDS[1]&0x0800) versio=1; else versio=0;  //Version A=0  Version B=1
       if(versio==0)
       {
        #if DEBUG
        sprintf(buffer,"Version=%d  Grupo=%02d ",versio,grupo); Serial.print(buffer);
     #endif
     switch(grupo)
     {
      case 0:
       #if DEBUG
       Serial.print("_RDS0__");
       #endif
       i=(RDS[1] & 3) <<1;
       seg_RDS[i]=(RDS[3]>>8);
       seg_RDS[i+1]=(RDS[3]&0xFF);
       //tft.setCursor(20,100);tft.setTextColor(BLUE, BLACK);
       for (i=0;i<8;i++)
       {
         #if DEBUG
         Serial.write(seg_RDS[i]);
         #endif
        // if(seg_RDS[i]>31 && seg_RDS[i]<128)
       //  tft.print(seg_RDS[i]);
        // else
       //  tft.setTextColor(BLUE, BLACK);
         //tft.clearScreen();
       }
       #if DEBUG
       Serial.println("---");
       #endif
       break;
      case 2:
       i=(RDS[1] & 15) <<2;
       seg_RDS1[i]=(RDS[2]>>8);
       seg_RDS1[i+1]=(RDS[2]&0xFF);
       seg_RDS1[i+2]=(RDS[3]>>8);
       seg_RDS1[i+3]=(RDS[3]&0xFF);
       #if DEBUG
       Serial.println("_RADIOTEXTO_");
               for (i=0;i<32;i++)  Serial.write(seg_RDS1[i]);
               Serial.println("-TXT-");
               #endif
               break;
               case 4:
               i=RDS[3]& 0x003f;
               minuto=(RDS[3]>>6)& 0x003f;
               hora=(RDS[3]>>12)& 0x000f;
               if(RDS[2]&1) hora+=16;
               hora+=i;
               z=RDS[2]>>1;
               julian=z;
               if(RDS[1]&1) julian+=32768;
               if(RDS[1]&2) julian+=65536;
               #if DEBUG
               Serial.print("_DATE_");
               Serial.print(" Juliano=");Serial.print(julian);
              // sprintf(buffer," %02d:%02d ",hora,minuto); tft.setCursor(50,110); tft.setTextColor(CYAN, BLACK); tft.print(buffer);
               Serial.println(buffer);
               #endif
               break;
               default:
               #if DEBUG
               Serial.println("__");
               #endif
               ;
             }
           }
  */
}

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#include <EEPROM.h>

#include <Wire.h>

#include <SPI.h>

#include <Adafruit_GFX.h>

//#include <TFT_ILI9163C.h>

#include <Adafruit_SSD1306.h>

#include <RDA5807M.h>

#include <RDSParser.h>

#include <radio.h>

//extern const uint8_t icon_radio[];

//extern const uint8_t icon_volume[];

RDA5807M radio; ///< Create an instance of a RDA5807 chip radio

#define DEBUG 0

#define OLED_RESET 4

Adafruit_SSD1306 tft(OLED_RESET);

RDSParser rds;

enum RADIO_STATE {

STATE_PARSECOMMAND, ///< waiting for a new command character.

STATE_PARSEINT, ///< waiting for digits for the parameter.

STATE_EXEC ///< executing the command.

};

RADIO_STATE state; ///< The state variable is used for parsing input characters.

const int entrada = A0;

int entradaV = 0;

int menu;

#define MAXmenu 3

int menux;

#define MAXmenux 3

static char* menuS[] = {" ", "MANUAL TUNE", "VOLUME ", "AUTO TUNE", "INFO "};

int volumen, volumenOld = 7;

int frecuencia, frecuenciaOld;

int signal_level;

unsigned int z, z1;

byte xfrecu, xfrecuOld;

unsigned int estado[6];

unsigned long time, time1, time2, time3;

char buffer[30];

unsigned int RDS[4];

char seg_RDS[8];

char seg_RDS1[64];

char indexRDS1;

char hora, minuto, grupo, versio;

unsigned long julian;

int mezcla;

//radio.debugEnable();

void RDS_process(uint16_t block1, uint16_t block2, uint16_t block3, uint16_t block4) {

rds.processData(block1, block2, block3, block4);

}

void setup()

{

Wire.begin();

//Serial.begin(9600);

Serial.begin(57600);

tft.begin(SSD1306_SWITCHCAPVCC, 0x3C);

radio.init();

radio.debugEnable();

tft.display();

delay(20);

// Clear the buffer.

tft.clearDisplay();

// read value of last frequency

frecuencia = EEPROM.read(201);

volumen = EEPROM.read(202);

if (volumen < 0) volumen = 0;

if (volumen > 15) volumen = 15;

if (frecuencia < 0) frecuencia = 0;

if (frecuencia > 210) frecuencia = 210;

tft.setRotation(0);

tft.setTextColor(WHITE);

tft.setCursor(95, 0);

// tft.print("Nivel semnal :");

tft.print(signal_level); tft.display();

tft.print("/15 ");

// draw an antenna

tft.drawLine(103, 9, 103, 13, WHITE);

tft.drawCircle(103, 9, 2, WHITE);

WriteReg(0x02, 0xC00d); // write 0xC00d into Reg.2 ( soft reset, enable,RDS, )

WriteReg(0x05, 0x84d8); // write ,0x84d8 into Reg.3

time3 = time2 = time1 = time = millis();

menu = 3;

canal(frecuencia);

// clearRDS;

state = STATE_PARSECOMMAND;

// setup the information chain for RDS data.

radio.attachReceiveRDS(RDS_process);

rds.attachServicenNameCallback(tftServiceName);

// rds.attachTimeCallback(tftTime);

}

void tftServiceName(char *name)

{

size_t len = strlen(name);

tft.setCursor(0, 25);

tft.setTextSize(1.5);

tft.setTextColor(WHITE, BLACK);

tft.print(name); tft.setTextColor(WHITE, BLACK); tft.display();

while (len < 8) {

tft.print(' '); tft.setTextColor(WHITE, BLACK); tft.display();

len++;

} // while

} // tftServiceName()

void loop() {

int newPos;

unsigned long now = millis();

// static unsigned long nextFreqTime = 0;

static unsigned long nextRadioInfoTime = 0;

char c;

entradaV = analogRead(entrada);

#if DEBUG

Serial.print("sensor = " ); Serial.println(entradaV); delay(50);

#endif

// Boton menu

if (entradaV > 500 && entradaV < 524)

{

Serial.print(entradaV);

menu++;

if (menu > MAXmenu)menu = 1;

Visualizar();

#if DEBUG

Serial.print("menu = " ); Serial.println(menu);

#endif

while (1020 > analogRead(entrada))delay(5);

}

// Boton derecho

if ( entradaV < 50)

{

Serial.print(entradaV);

menux++;

if (menux > MAXmenux)menux = MAXmenux;

#if DEBUG

Serial.print("menux = " ); Serial.println(menux);

#endif

switch (menu)

{

case 1:

frecuencia++;

if (frecuencia > 210)frecuencia = 210; // верхняя граница частот

delay(130);

break;

case 2:

volumen++;

if (volumen > 15)volumen = 15;

while (1020 > analogRead(entrada))delay(5);

break;

case 3:

busqueda(0);

while (1020 > analogRead(entrada))delay(5);

break;

case 4:

// LcdClear();

tft.clearDisplay();

// visualPI();

delay(3000);

// LcdClear();

tft.clearDisplay();

frecuenciaOld = -1;

break;

}

// Boton izquierdo

if ( entradaV < 700 && entradaV > 660)

//if( entradaV<700 && entradaV>660)

{

Serial.print(entradaV);

menux--;

if (menux < 1)menux = 1;

#if DEBUG

Serial.print("menux = " ); Serial.println(menux);

#endif

switch (menu)

{

case 1:

frecuencia--;

if (frecuencia < 0)frecuencia = 0;

delay(130);

break;

case 2:

volumen--;

if (volumen < 0)volumen = 0;

while (1020 > analogRead(entrada))delay(5);

break;

case 3:

busqueda(1);

while (1020 > analogRead(entrada))delay(5);

break;

case 4:

// LcdClear();

tft.clearDisplay();

//tft.print(frecuencia);

//visualPTY();

delay(3000);

// LcdClear();

tft.clearDisplay();

frecuenciaOld = -1;

break;

}

if ( millis() - time2 > 50)

{

ReadEstado();

time1 = millis();

//RDS

if ((estado[0] & 0x8000) != 0) {

get_RDS();

}

if ( millis() - time3 > 500)

{

time3 = millis();

Visualizar();

}

if ( frecuencia != frecuenciaOld)

{

frecuenciaOld = frecuencia;

z = 870 + frecuencia;

EEPROM.write(201, frecuencia);

#if DEBUG

Serial.print("Frecuencia = " ); Serial.println(frecuencia);

#endif

sprintf(buffer, "%04d ", z);

// tft.drawBitmap(80, 2, icon_volume, 24, 10, WHITE);

//tft.display();

tft.setCursor(0, 0);

tft.setTextSize(2);

tft.setTextColor(WHITE, BLACK);

for (z = 0; z < 5; z++)

{

if (z == 0) {

if (frecuencia < 130) tft.print(" ");

else tft.print(buffer[0]); tft.setTextColor(WHITE, BLACK);

}

if (z == 3) tft.print(","); tft.setTextColor(WHITE, BLACK);

if (z > 0) tft.print(buffer[z]); tft.setTextColor(WHITE, BLACK);

}

// LcdString("MHz");

tft.setCursor(65, 5);

tft.setTextSize(1);

tft.setTextColor(WHITE, BLACK);

tft.print("MHz");

tft.setTextColor(WHITE, BLACK);

tft.display();

canal(frecuencia);

// clearRDS();

}

//Cambio de volumen

if (volumen != volumenOld)

{

volumenOld = volumen;

sprintf(buffer, "Volum %02d", volumen); tft.setCursor(62, 25); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print(buffer); tft.print(" ");

tft.display(); tft.print("/15");

WriteReg(5, 0x84D0 | volumen);

EEPROM.write(202, volumen);

}

// check for RDS data

radio.checkRDS();

}

void busqueda(byte direc)

{

byte i;

if (!direc) WriteReg(0x02, 0xC30d); else WriteReg(0x02, 0xC10d);

for (i = 0; i < 10; i++)

{

delay(200);

ReadEstado();

if (estado[0] & 0x4000)

{

//Serial.println("Emisora encontrada");

frecuencia = estado[0] & 0x03ff;

break;

}

void Visualizar(void)

{

// tft.setCursor(3, 13); tft.setTextSize(2); tft.setTextColor(WHITE, BLACK); tft.print("FM");

// tft.setCursor(27, 20); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print("RDA5807-");

sprintf(buffer, "%s", menuS[menu]); tft.setCursor(5, 17); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print(buffer);

//Detectar señal stereo

tft.display();

tft.setCursor(85, 15);

tft.setTextColor(BLACK, WHITE);

if ((estado[0] & 0x0400) == 0) tft.print(""); else tft.setTextColor(BLACK, WHITE); tft.print("Stereo"); tft.setTextColor(BLACK, WHITE);

tft.display();

//Señal

// z=estado[1]>>10; sprintf(buffer,"S-%02d",z); tft.setCursor(58,0); tft.setTextColor(WHITE, BLACK); tft.print(buffer); tft.setCursor(25,0);tft.setTextColor(WHITE, BLACK);tft.print("Canal");

sprintf(buffer, "Volum %02d", volumen); tft.setCursor(62, 25); tft.setTextSize(1); tft.setTextColor(WHITE, BLACK); tft.print(buffer); //DUBLARE AFISARE VOLUM

tft.display(); tft.print("/15");

frecuencia = estado[0] & 0x03ff;

}

void canal( int canal)

{

byte numeroH, numeroL;

numeroH = canal >> 2;

numeroL = ((canal & 3) << 6 | 0x10);

Wire.beginTransmission(0x11);

Wire.write(0x03);

Wire.write(numeroH); // write frequency into bits 15:6, set tune bit

Wire.write(numeroL);

Wire.endTransmission();

}

void WriteReg(byte reg, unsigned int valor)

{

Wire.beginTransmission(0x11);

Wire.write(reg); Wire.write(valor >> 8); Wire.write(valor & 0xFF);

Wire.endTransmission();

//delay(50);

}

//RDA5807_adrs=0x10;

// I2C-Address RDA Chip for sequential Access

int ReadEstado()

{

Wire.requestFrom(0x10, 12);

for (int i = 0; i < 6; i++) {

estado[i] = 256 * Wire.read () + Wire.read();

}

Wire.endTransmission();

}

//READ RDS Direccion 0x11 for random access

void ReadW()

{

// Wire.beginTransmission(0x11); // Device 0x11 for random access

// Wire.write(0x0C); // Start at Register 0x0C

// Wire.endTransmission(0); // restart condition

// Wire.requestFrom(0x11,8, 1); // Retransmit device address with READ, followed by 8 bytes

// for (int i=0; i<4; i++) {RDS[i]=256*Wire.read()+Wire.read();} // Read Data into Array of Unsigned Ints

// Wire.endTransmission();

}

void get_RDS()

{

/* int i;

ReadW();

grupo=(RDS[1]>>12)&0xf;

if(RDS[1]&0x0800) versio=1; else versio=0; //Version A=0 Version B=1

if(versio==0)

{

#if DEBUG

sprintf(buffer,"Version=%d Grupo=%02d ",versio,grupo); Serial.print(buffer);

#endif

switch(grupo)

{

case 0:

#if DEBUG

Serial.print("_RDS0__");

#endif

i=(RDS[1] & 3) <<1;

seg_RDS[i]=(RDS[3]>>8);

seg_RDS[i+1]=(RDS[3]&0xFF);

//tft.setCursor(20,100);tft.setTextColor(BLUE, BLACK);

for (i=0;i<8;i++)

{

#if DEBUG

Serial.write(seg_RDS[i]);

#endif

// if(seg_RDS[i]>31 && seg_RDS[i]<128)

// tft.print(seg_RDS[i]);

// else

// tft.setTextColor(BLUE, BLACK);

//tft.clearScreen();

}

#if DEBUG

Serial.println("---");

#endif

break;

case 2:

i=(RDS[1] & 15) <<2;

seg_RDS1[i]=(RDS[2]>>8);

seg_RDS1[i+1]=(RDS[2]&0xFF);

seg_RDS1[i+2]=(RDS[3]>>8);

seg_RDS1[i+3]=(RDS[3]&0xFF);

#if DEBUG

Serial.println("_RADIOTEXTO_");

for (i=0;i<32;i++) Serial.write(seg_RDS1[i]);

Serial.println("-TXT-");

#endif

break;

case 4:

i=RDS[3]& 0x003f;

minuto=(RDS[3]>>6)& 0x003f;

hora=(RDS[3]>>12)& 0x000f;

if(RDS[2]&1) hora+=16;

hora+=i;

z=RDS[2]>>1;

julian=z;

if(RDS[1]&1) julian+=32768;

if(RDS[1]&2) julian+=65536;

#if DEBUG

Serial.print("_DATE_");

Serial.print(" Juliano=");Serial.print(julian);

// sprintf(buffer," %02d:%02d ",hora,minuto); tft.setCursor(50,110); tft.setTextColor(CYAN, BLACK); tft.print(buffer);

Serial.println(buffer);

#endif

break;

default:

#if DEBUG

Serial.println("__");

#endif

;

}

Simple FM Radio Receiver Using Arduino And RDA5807M

Circuit Diagram

Components Required

What is an RDA5807M FM Frequency Receiver?

PCB Design

Working Principle of FM Radio Circuit Using Arduino

Arduino Code

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