#include<Arduino.h>
#include<Wire.h>
#include<SI4735.h>
#define RESET_PIN 42 // GPIO12
#define TOUCH_BAND_BUTTON_UP 13 // Next band (GPIO13)
#define TOUCH_BAND_BUTTON_DOWN 14 // Previous band (GPIO14)
// I2C bus pin on ESP32
#define ESP32_I2C_SDA 15 // GPIO21
#define ESP32_I2C_SCL 16 // GPIO22
#define CAPACITANCE 30
#define AM_FUNCTION 1
#define FM_FUNCTION 0
uint16_t currentFrequency;
uint16_t previousFrequency;
uint8_t bandwidthIdx = 0;
const char *bandwidth[] = {"6", "4", "3", "2", "1", "1.8", "2.5"};
SI4735 si4735;
void showHelp()
{
Serial.println("Type F to FM; A to MW; L to LW; and 1 to SW");
Serial.println("Type U to increase and D to decrease the frequency");
Serial.println("Type S or s to seek station Up or Down");
Serial.println("Type + or - to volume Up or Down");
Serial.println("Type 0 to show current status");
Serial.println("Type B to change Bandwidth filter");
Serial.println("Type ? to this help.");
Serial.println("==================================================");
delay(1000);
}
// Show current frequency
void showStatus()
{
si4735.getStatus();
si4735.getCurrentReceivedSignalQuality();
Serial.print("You are tuned on ");
if (si4735.isCurrentTuneFM())
{
Serial.print(String(currentFrequency / 100.0, 2));
Serial.print("MHz ");
Serial.print((si4735.getCurrentPilot()) ? "STEREO" : "MONO");
}
else
{
Serial.print(currentFrequency);
Serial.print("kHz");
}
Serial.print(" [SNR:");
Serial.print(si4735.getCurrentSNR());
Serial.print("dB");
Serial.print(" Signal:");
Serial.print(si4735.getCurrentRSSI());
Serial.println("dBuV]");
}
int touchUp, touchDown;
int readX(int pin) {
int val;
val = 0;
for (int i = 0; i < 50; i++ )
val += touchRead(pin);
return (val / 50);
}
void setup()
{
Serial.begin(115200);
while(!Serial);
digitalWrite(RESET_PIN, HIGH);
Serial.println("AM and FM station tuning test.");
showHelp();
// The line below may be necessary to setup I2C pins on ESP32
Wire.setPins(ESP32_I2C_SDA, ESP32_I2C_SCL);
Wire.begin();
delay(500);
si4735.setup(RESET_PIN, 0, FM_FUNCTION, SI473X_ANALOG_AUDIO, 1,0);
// Starts defaul radio function and band (FM; from 84 to 108 MHz; 103.9 MHz; step 100kHz)
si4735.setFM(8400, 10800, 10390, 10);
delay(500);
currentFrequency = previousFrequency = si4735.getFrequency();
si4735.setVolume(55);
showStatus();
}
// Main
void loop()
{
touchUp = readX(TOUCH_BAND_BUTTON_UP);
touchDown = readX(TOUCH_BAND_BUTTON_DOWN);
if (Serial.available() > 0)
{
char key = Serial.read();
switch (key)
{
case '+':
si4735.volumeUp();
break;
case '-':
si4735.volumeDown();
break;
case 'a':
case 'A':
si4735.setAM(570, 1710, 810, 10);
break;
case 'f':
case 'F':
si4735.setFM(8600, 10800, 10390, 10);
break;
case '1':
si4735.setAM(9400, 9990, 9600, 5);
break;
case 'U':
case 'u':
si4735.frequencyUp();
break;
case 'D':
case 'd':
si4735.frequencyDown();
break;
case 'b':
case 'B':
if (si4735.isCurrentTuneFM())
{
Serial.println("Not valid for FM");
}
else
{
if (bandwidthIdx > 6)
bandwidthIdx = 0;
si4735.setBandwidth(bandwidthIdx, 1);
Serial.print("Filter - Bandwidth: ");
Serial.print(String(bandwidth[bandwidthIdx]));
Serial.println(" kHz");
bandwidthIdx++;
}
break;
case 'S':
si4735.seekStationUp();
break;
case 's':
si4735.seekStationDown();
break;
case '0':
showStatus();
break;
case '?':
showHelp();
break;
default:
break;
}
} else if ( (touchUp < CAPACITANCE) ) // goes to the next band
{
si4735.seekStationUp();;
delay(100);
}
else if ( (touchDown < CAPACITANCE) ) // goes to the previous band
{
si4735.seekStationDown();
delay(100);
}
delay(100);
currentFrequency = si4735.getCurrentFrequency();
if (currentFrequency != previousFrequency)
{
previousFrequency = currentFrequency;
showStatus();
delay(300);
}
}
