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.
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.
PCB View
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.
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.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 | #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 ; } } */ } |