RDA5807

Arduino Library for SINGLE-CHIP BROADCAST FM RADIO TUNER RDA5807

View on GitHub

RDA5807 Arduino Library

It is a cross-platform Arduino library for the RDA5807 and RDA7088 family of devices from RDA Microelectronics. This library is compatible with official Arduino boards, ATtiny, STM32, ESP32, and more. Utilizing the I2C protocol, it provides an easier interface for controlling the RDA5807 device. The library was developed based on the ‘RDA5807MS - SINGLE-CHIP BROADCAST FM RADIO TUNER - Rev.1.1–Aug.2015’ and the ‘RDA5807FP - SINGLE-CHIP BROADCAST FM RADIO TUNER’ documentation from RDA Microelectronics. Please refer to the table of contents below to make the best use of this documentation.

This library can be freely distributed using the MIT Free Software model. It means you can copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software. See MIT License for more details.

Copyright (c) 2019 Ricardo Lima Caratti.

Contact: pu2clr@gmail.com.

If you find this project useful, consider making a donation so that the author of this library can purchase components and modules for improvements and testing of this library. Click here to donate.

About Me

I hold a Master’s degree in Educational Technology from the Federal University of Ceará, where I delved into the ways technology can enhance learning experiences. My passion for computer science led me to specialize in it, focusing on Distributed Systems Development with an Object-Oriented approach, at the University of Brasília. My academic journey began with a Bachelor’s degree in Information Systems from the União Pioneira de Integração Social (UPIS-Brasília). Outside the classroom, my main hobbies are electronics and Amateur Radio.

Contents

  1. Preface
  2. RDA5807 family devices and RDA5807 Arduino Library
  3. Library Installation
  4. Minimal receiver implementation with this library
  5. Examples summary
  6. Boards where this library has been tested
  7. RDA5807M breakout
  8. RDA5807FP and RDA7088 standalone IC
  9. API Documentation
  10. MIT License
  11. Basic Schematic
  12. All Schematics, photos and videos
  13. Storing data into the EEPROM
  14. Extending RDA5807 class
  15. LilyGO/T-Embed and RDA5807 setup
  16. Source code - Arduino Sketches
  17. Videos about this library

Attention

Preface

The RDA5807 is an FM DSP integrated circuit receiver that operates in the 50 to 115MHz range and includes support for a low-noise amplifier. This device requires fewer external components compared to other similar products and offers features such as RDS/RBDS functionalities, direct auto gain control (AGC), and real-time adaptive noise cancellation. The PU2CLR RDA5807 Arduino Library was developed to maximize the functionalities of this device. The primary motivations for developing this library were to understand the operational aspects of this receiver and to share this knowledge. Currently, the library has over 80 functions implemented. I hope this work will prove useful to electronics experimenters and hobbyists.

This documentation reflects the author’s understanding of the IC RDA5807 family’s operation. With that said, there may be inaccuracies or incorrect information. If you find any errors, please bring them to my attention.

Please, check the API Documentation for more details.

Your support is important.

If you want to support this library development, consider joining this project via Github. Alternatively, make suggestions on new features and report errors if you find them. Thank you!

There is a Facebook group called DSP receivers for hobbyists where the purpose is exchanging experiences with projects based on RDA5807 IC devices.

RDA5807 family devices and RDA5807 Arduino Library

This library has been successfully tested on RDA5807M and RDA5807FP devices. The videos below show some examples of using this library with RDA5807M and RDA5807FP.


FM receiver based on RDA5807 and LilyGO/T-Embed panel


RDS and RDA5807 using this library


RDS - TFT Display

RDA5807 main features implemented by this library

  1. 76–108 MHz
  2. Seek tuning
  3. Automatic frequency control (AFC)
  4. Automatic gain control (AGC)
  5. Programmable de-emphasis (50/75 μs)
  6. Adaptive noise suppression
  7. Volume control
  8. Bass
  9. Mute control
  10. Mono/Stereo control
  11. RDS/RBDS Processor
  12. I2S Digital Audio (RDA5807FP)
  13. LNA (Low Noise Amplifiers)
  14. Softmute
  15. Stereo / Mono
  16. Step


Library Installation

The easiest method to install this library is via your Arduino IDE. All you have to do is:

  1. Select Tools menu;
  2. Select Manage Libraries option;
  3. In the text box (top windows), type PU2CLR or RDA5807;
  4. Select the PU2CLR RDA5807.

The images below show how you can install this library via your Arduino IDE from Manage Libraries tool.


Arduino IDE - Manage Libraries menu option


Arduino IDE - Looking for the library RDA5807

Installing via the repository

With this approach, you will have the most current version of the library. However, it may not be the most stable version. This is because the current version is always in development. Prefer releases. Do you need some old version (release) of this library? If yes, check here.

First, you have to download this library in zip format.
After, unzip the RDA5807-master.zip file in your Arduino Library folder.

Installing the most current version via arduino-cli

The commands below Install the latest version of the PU2CLR RDA5807 Arduino Library from github. As said before, unlike a release (installed from Arduino IDE) this method installs the current version of the PU2CLR RDA5807 Arduino Library (latest modifications even if not yet released).

On macOS or Linux

curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh
export ARDUINO_LIBRARY_ENABLE_UNSAFE_INSTALL=true
./bin/arduino-cli lib install --git-url https://github.com/pu2clr/RDA5807

On Windows 10 or 11

Run the command shell (cmd / Command Prompt) and follow the steps below.

echo off  
curl -fsSL https://downloads.arduino.cc/arduino-cli/arduino-cli_latest_Windows_64bit.zip --output arduinocli.zip
tar -xf arduinocli.zip 
set ARDUINO_LIBRARY_ENABLE_UNSAFE_INSTALL=true
.\arduino-cli lib install --git-url https://github.com/pu2clr/RDA5807

How to use the RDA5807 Arduino Library in your sketch

The following source-code snippet shows a common way of using the RDA5807 library in your application. Click here to know about all the functions integrated in this library.

#include <RDA5807.h>

RDA5807 rx;

void setup() {
    .
    .
    .
    // Start your receiver here
    rx.setup();
    rx.setVolume(6);
    rx.setFrequency(some_frequency); // Example 10390 for 103,9 MHz
    .
    .
    .
}

void loop() {
    //  Control your receiver here 
    .
    .
    .
}

Minimal receiver implementation with this library

The code below shows the minimal implementation using this library.

#include <RDA5807.h> 
RDA5807 rx; 
void setup() {
  rx.setup(); // Starts the receiver with default parameters
  rx.setFrequency(10390); // Tunes in 103.9 MHz  - Switch to your local favorite station
}
void loop() {

}

A minimalist receiver implementation with two pushbuttons

The following code illustrates a minimalist implementation of a receiver based on RDA5807 and this library. For this receiver, the user has two pushbuttons to tune station (Seek Up and Seek Down).

#include <RDA5807.h> // It is a minimal receicer with two push buttons (ATmega328 - Uno, Nano etc)
RDA5807 rx; 
void setup() {
  pinMode(4, INPUT_PULLUP); // Arduino pin 4 - Seek station down
  pinMode(5, INPUT_PULLUP); // Arduino pin 5 - Seek station up
  rx.setup(); // Starts the receiver with default parameters
  rx.setFrequency(10390); // Tunes in 103.9 MHz  - Switch to your local favorite station
}
void loop() {
  if (digitalRead(4) == LOW) rx.seek(RDA_SEEK_WRAP,RDA_SEEK_DOWN);
  if (digitalRead(5) == LOW) rx.seek(RDA_SEEK_WRAP,RDA_SEEK_UP);
  delay(200);
}


You can use the sketch above with the circuit shown below.


Minimalist receiver based on RDA5807


See also other schematics with RDA5807.



MINIMALIST RECEIVER WITH RDA5807 ARDUINO LIBRARY

Examples summary

The following table shows the main examples implemented in this library. These examples can guide you to build your own receiver.

Sketch Name Description
RDA5807_00_CIRCUIT_TEST Useful to check the circuit and many functions implemented in this library
RDA5807_00_MINIMAL_RECEIVER It is a minimal receicer with two push buttons (ATmega328 - Uno, Nano etc)
RDA5807_01_SERIAL_MONITOR/
RDA5807_01_ALL_TEST_SERIAL_MONITOR		 More about Tune, Volume, Seek and RDS features
RDA5807_01_SERIAL_MONITOR/
RDA5807_01_RDS_TEST_SERIAL_MONITOR		 Test RDS functions using Serial Monitor
RDA5807_01_SERIAL_MONITOR/
RDA5807_02_ESP32		 Test and validation of RDA5807 on ESP32 board
RDA5807_01_SERIAL_MONITOR/
RDA5807_03_STM32		 Test and validation of RDA5807 on STM32 board
RDA5807_02_TFT_display This sketch uses an Arduino Pro Mini, 3.3V (8MZ) with a SPI TFT ST7735 1.8
RDA5807_03_ATTINY_84_85 Test and validation of RDA5807 on ATtiny84 device
RDA5807_04_NOKIA5110 This sketch uses an Arduino Nano with NOKIA 5110 display
RDA5807_05_LCD16X02 This sketch uses an Arduino Nano with LCD16X02 DISPLAY
RDA5807_05_LCD16X02_ESP32 This sketch uses an ESP32 with LCD16X02 DISPLAY
RDA5807_05_LCD16X02_ESP32_I2S I2S setup - This sketch uses an ESP32 with LCD16X02 DISPLAY and MAX98357A I2S setup
RDA5807_06_UNO_TM1638 This sketch drives the RDA5807 FM receiver and TM1638 (seven-segment display control)
Arduino Nano and OLED with Tiny4kOLED library Nano and OLED implementation V1
Arduino Nano and OLED (Adafruit_GFX and Adafruit_SSD1306) This sketch works on Atmega328 and LGT8FX based board. It is a I2C OLED setup
LilyGO/T-Embed and RDA5807 setup This sketch was an adaptation of the Volos’s sketch and uses PU2CLR RDA5807 Arduino Library with LilyGO T-Embed.

See the folder examples do know more


Boards where this library has been tested

This library can be useful to develop cross-platform software. So far, it has been successfully tested on the architectures shown below. Please, pay attention to the pins used for I2C communication.

  Board Need voltage converter I²C Pins Features
1 Arduino Pro Mini 3.3V 8MHz No A4 and A5 More…
2 Mega 2560 Pro Yes 20 and 21 More…
3 ESP WEMOS LOLIN32 No GPIO21 and GPIO22 [4] More…
4 ESP32 Dev Module No GPIO21 and GPIO22 [4] More…
5 ESP32 Wrover Module No GPIO21 and GPIO22 [4] More…
6 ESP8266 No GPIO4 and GPIO5 More…
7 Arduino UNO Yes A4 and A5 More…
8 Arduino NANO ATmega 328 Yes A4 and A5 More…
9 Arduino NANO ATmega 168 Yes A4 and A5 More…
10 Arduino NANO 33 IoT No [6] A4 and A5 More…
11 Arduino Yún / ATmega-32u4 Yes 2 and 3 More…
12 ATtiny84 No 7 and 8 More…
13 ATtiny85 No 5 and 7 More…
14 Arduino DUE No 2 and 3 More…
15 BlueDuino 3.3V (ATmega-32u4) No 2 and 3 More…
16 Arduino Mini Pro 5V 16Mhz Yes 2 and 3 More…
17 STM32F746G-DISCO No - More…
18 STM32F103 Series No PB6 (SCL) and PB7(SDA) More…
19 STM32F411 Series No PB6 (SCL) and PB7(SDA) More…
20 Raspberry Pi Pico No GP0 (0) and GP1 (1) More…
21 WeAct Studio RP2040 Pico No GP0 (0) and GP1 (1) More…
22 Seeeduino XIAO No A4 and A5 More…
23 Teensy 3.1 No A4 and A5 More…
24 Teensy 4.1 No A4 and A5 More…
25 Atmega8 No PC4 and PC5 More…
26 Atmega32 No PC1 and PC0 More…
27 Atmega128 No PC1 and PC0 More…
28 LGT8F328P No A4 and A5 More…
29 LUATOS ESP32C3 No GPIO4 and GPIO5 More…
  1. More about ESP boards on ESPRESSIF Development Boards.
  2. More about BlueDuino on Seed.
  3. On Arduino.cc you can see the technical specification about many board.
  4. It seams that in some ESP32 board, the I²C bus is not configured properly by default. However, you can set almost any pin on ESP32 to setup I²C capabilities. All you have to do is call Wire.begin(SDA, SCL); where SDA and SCL are the ESP32 GPIO pins. See the folder examples to check how to use ESP32 devices.
  5. Arduino Nano 33 BLE only supports 3.3V I/Os and is NOT 5V tolerant so please make sure you are not directly connecting 5V signals to this board or it will be damaged. Also, as opposed to Arduino Nano boards that support 5V operation, the 5V pin does NOT supply voltage but is rather connected, through a jumper, to the USB power input.


RDA5807M breakout

The photos below show a Breakout that uses the RDA5807M.

Front side

RDA5807 Breakout board side A

Back side

RDA5807 Breakout board side B


RDA5807FP and RDA7088 standalone IC

If you are using the standalone RDA5807FP you must add some parts to make it work. In my opinion, there is no big reasons to use the RDA5807FP instead of the RDA5807M breakout in most applications. I think the most important situations are the possibility to use the digital audio configuration via I2S protocol or GPIO setup (Stereo indicator, interrupt etc). This library has function to deal with I2S and GPIO.

The RDA7088 has the same RDA5807FP pinout. However, I have noticed that some functions available in this library do not work prorpely. For example: RDS, Seek and Stereo functions have not worked on RDA7088 during tests with RDA5807 Arduino Library. In contrast, all functions implemented in this library work well on RDA5807FP. Prefer the RDA5807FP.

The photo below shows the RDA5807FP on a SOP16 board adapter.

RDA5807 Breakout board

RDA5807FP PINOUT

The image below shows the RDA5807FP pinout.

RDA5807 Breakout board


PIN Label Description
1 GPIO1 General purpose input/output
2 GND_1 Ground. Must be connected to ground
3 RFGND RF Ground. Must be connected to the ground or a special RF ground
4 FMIN FM signal input - Antenna
5 GND_2 Ground. Must be connected to ground
6 GND_3 Ground. Must be connected to ground
7 SCLK I2C clock
8 SDA I2C SDA/SDIO
9 RCLK 32.768kHz pasive crystal
10 VDD 3.3V power supply
11 GND_4 Ground. Must be connected to ground
12 ROUT Right audio output
13 LOUT Left audio output
14 GND_5 Ground. Must be connected to ground
15 GPIO3 General purpose input/output and stereo indicator
16 GPIO2 General purpose input/output

The two photos below shows the standalone RDA5807FP IC mounted on a homebrew board.

RDA5807 RDA5807FP setup 01


RDA5807 RDA5807FP setup 02


The schematic below shows the basic RDA5807FP setup.

RDA5807 RDA5807FP basic schematic

Components Value
R1 1K
R2 1K
R3 8 ~ 12K
R4 8 ~ 12K
C1 1nF (FMIN)
C2 and C3 4,7 ~ 10uF tantalum capacitor (stereo audio output)
Q1 32768 kHz passive crystal oscillator
J1 Audio stereo jack

The RDA5807FP on an Arduino Uno adapter

The photos below show the RDA5807FP setup on a Arduino Uno board adapter.

RDA5807FP on Arduino Uno Adapter 01

RDA5807FP on Arduino Uno Adapter 02

RDA5807FP on Arduino Uno Adapter 03


Video about the RDA5807, Arduino Uno and 7-segment display based on TM1638 device


MIT License

Copyright (c) 2019 Ricardo Lima Caratti

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


Schematic

The circuits below can help you to connect the arduino based board to the RDA5807 version you are using. In general, the RDA5807 can be found in kit or breakout form on Aliexpress, Amazon, eBay etc.

RDA5807M Breakout setup

RDA5807M Breakout setup

RDA5807M standalone IC setup (without breakout)

RDA5807M standalone IC setup (without breakout)

RDA5807FP standalone IC setup

RDA5807FP standalone IC setup

Arduino UNO, Pro mini or other based on ATmega 328 wireup.

Basic Schematic

RDA5807 / Description Arduino Pin
VCC 3.3V
SDA / SDIO A4
SCL / SCLK A5

Arduino, TFT7735 display and Push Buttons wireup.

Basic Schematic with TFT

Arduino UNO, Nano or other based on Atmega328 and SPI TFT ST7735 1.8” wireup

Device name Device Pin / Description Arduino Pin
Display TFT    
  RST (RESET) 8
  RS or DC 9
  CS or SS 10
  SDI 11
  CLK 13
RDA5807    
  VCC 3.3V
  SDIO (pin 8) A4
  SCLK (pin 7) A5
Buttons    
  Volume Up 4
  Volume Down 5
  Stereo/Mono 6
  RDS ON/off 7
  SEEK (encoder button) A0/14
Encoder    
  A 2
  B 3

RDA5807 breakout, ATtiny84, Encoder and Buttons schematic

Basic Schematic

RDA5807 breakout, ATtiny84, Encoder and Buttons wireup


RDA5807 pin Attiny84 REF pin Physical pin
SEEK_UP 3 10
SEEK_DOWN 5 8
ENCODER_PIN_A 0 13
ENCODER_PIN_B 1 12
SDIO / SDA SDA 7
SCLK / CLK SCL 9

RDA5807 breakout, Arduino Nano and Nokia 5110 display wireup

Device name Nokia 5110 Arduino
NOKIA 5110 Pin function Nano Pin
  (1) RST (RESET) 8
  (2) CE or CS 9
  (3) DC or DO 10
  (4) DIN or DI or MOSI 11
  (5) CLK 13
  (6) VCC (3V-5V) +VCC
  (7) BL/DL/LIGHT +VCC
  (8) GND GND
RDA5807 Pin Function  
  VCC 3.3V
  SDIO (pin 8) A4
  SCLK (pin 7) A5
Buttons    
  Volume Up 4
  Volume Down 5
  Stereo/Mono 6
  RDS ON/off 7
  SEEK (encoder button) A0/14
Encoder    
  A 2
  B 3

Basic Nokia 5110 Schematic


Arduino Nano, RDA5807 and Nokia 5110 setup on Breadboard

RDA5807 and Nokia 5110 on Breadboard

RDA5807 breakout, Arduino Nano and LCD16X02 display wireup

Basic LCD16X02 Schematic


Device name Device Pin / Description Arduino Pin
LCD 16x2 or 20x4    
  D4 D7
  D5 D6
  D6 D5
  D7 D4
  RS D12
  E/ENA D13
  RW & VSS & K (16) GND
  A (15) & VDD +Vcc
RDA5807    
  VCC 3.3V
  SDIO (pin 8) A4
  SCLK (pin 7) A5
Buttons    
  Volume Up 8
  Volume Down 9
  Stereo/Mono 10
  RDS ON/off 11
  SEEK (encoder button) D14/A0
Encoder    
  A 2
  B 3

RDA5807FP setup, ESP32 and LCD16X02 display wireup

Basic LCD16X02 Schematic


Wire up ESP32 Dev Module, RDA5807 and LCD16x02 or LCD16x04

Device name Device Pin / Description Arduino Pin
LCD 16x2 or 20x4    
  D4 GPIO18
  D5 GPIO17
  D6 GPIO16
  D7 GPIO15
  RS GPIO19
  E/ENA GPIO23
  RW & VSS & K (16) GND
  A (15) & VDD +Vcc
RDA5807FP (See schematic)    
  VCC 3.3V
  SDIO / SDA (pin 8) GPIO21
  SCLK (pin 7) GPIO22
Buttons    
  Volume Up GPIO32
  Volume Down GPIO33
  Stereo/Mono GPIO25
  RDS On/Off GPIO26
Encoder    
  A GPIO13
  B GPIO14
  PUSH BUTTON (encoder) GPIO27

ATTENTION: Be guided by the ESP32 IO/GPIO pins.

Storing Data into the EEPROM

The EEPROM has a lifespan of around 100,000 write/erase cycles. According to the “Atmel” datasheet, page 19, “The Atmel® ATmega328P contains 1Kbyte of data EEPROM memory. It is organized as a separate data space, in which single bytes can be read and written. The EEPROM has an endurance of at least 100,000 write/erase cycles.” Consequently, writing data to the EEPROM every time the system status changes could severely limit the application’s lifespan. To address this issue, several strategies can be used to optimize EEPROM writes.

Approach

This approach involves storing data only when crucial system statuses change. The aim is to minimize unnecessary writes to the EEPROM.

Steps:

  1. Select the Data: Choose the data you wish to store in the EEPROM.
  2. Monitor the Data: Add code to your sketch to monitor the selected data.
  3. Criteria for Saving Data: Define the criteria that will trigger a write to the EEPROM. Generally, a good criterion involves any useful data change AND a time interval. This will depend on your specific application.
  4. Optimize Writes: Consider using the EEPROM.update method instead of EEPROM.write. The .update method will not write information if it matches what is already stored. On ESP32 and other MCUs, the EEPROM.write implementation functions similarly to EEPROM.update.
  5. Restore Data: Add code to retrieve the data from EEPROM.
  6. Data Validation: Include code to check whether valid data exists in the EEPROM. This could be a single byte or an identification number (ID) that the system recognizes as valid data.
  7. Data Erasure: Add code to erase specific information in the EEPROM. This usually means changing the stored ID. Essentially, you do not need to erase all the data to reset the system—just alter the ID value.
  8. System Reset: Add code to reset the system. Upon system startup, check if a designated button is pressed and then erase the ID.

The code below can guide you to deal with the RDA5807 data and Arduino Board EEPROM


#define STORE_TIME 10000  	// Time of inactivity to make the current receiver status writable (10 seconds).

const uint8_t app_id = 35; 	// Application ID. Any value from 1 to 255.  It will be useful to check the EEPROM content before processing useful data
const int eeprom_address = 0;  // Address where the data will be stored into EEPROM
long storeTime = millis(); 	// elapsed time control

RDA5807 rx.

void setup() {

  .
  .
  .

  // If you want to reset the eeprom, keep the  button pressed during statup
  if (digitalRead(GIVEN_BUTTON) == LOW)
  {
	EEPROM.write(eeprom_address, 0); // Changes the application ID. It invalidates all stotred information.
	delay(2000);
  }

  .
  .
  .

  rx.setup();

  // Checking the EEPROM content and read if it has valid information
  if (EEPROM.read(eeprom_address) == app_id)
  {
	readAllReceiverInformation();
  }

  .
  .
  .

}


void saveAllReceiverInformation()
{
  EEPROM.update(eeprom_address, app_id);                  	// stores the app id;
  EEPROM.update(eeprom_address + 1, rx.getVolume());  	// stores the current Volume
  EEPROM.update(eeprom_address + 3, currentFrequency >> 8);   // Store the current frequency
  EEPROM.update(eeprom_address + 4, currentFrequency & 0XFF);
  .
  .
  .

}


void readAllReceiverInformation()
{
  volume = EEPROM.read(eeprom_address + 1);             	// Gets the stored volume;
  currentFrequency = EEPROM.read(eeprom_address + 3) << 8;  // Gets the stored frequency
  currentFrequency |= EEPROM.read(eeprom_address + 4);
  .
  .
  .
}


void loop() {
  .
  .
  .
  // Monitor your data and set statusChanged variable to true if any useful data has changed.
  .
  .
  .

  // check if some status was changed
  if ( statusChanged )
  {
	// If the status has changed and the elapsed time is less than minimal time, wait a bit more for saving new data.
	if ((millis() - storeTime) > STORE_TIME)
	{
  	saveAllReceiverInformation();
  	storeTime = millis();
  	statusChanged = false;
	}
  }

}

The sketches below use the Arduino board internal EEPROM to save data.

The following table shows some examples that implement functions that save and restore data using the Arduino based board EEPROM and ESP32.

Sketch Name Description
RDA5807_04_NOKIA5110 This sketch uses an Arduino Nano with NOKIA 5110 display
RDA5807_05_LCD16X02 This sketch uses an Arduino Nano with LCD16X02 DISPLAY
RDA5807_05_LCD16X02_ESP32 This sketch uses an ESP32 with LCD16X02 DISPLAY
RDA5807_06_UNO_TM1638 This sketch drives the RDA5807 FM receiver and TM1638 (seven-segment display control)

Extending the RDA5807 Arduino Library by exteding RDA5807 class

The most effective way to customize the PU2CLR RDA5807 Arduino Library for your specific requirements is by extending the existing library using the C++ Object-Oriented Programming (OOP) approach.

When Should You Extend the RDA5807 Class?

There are at least two compelling reasons to extend the RDA5807 class:

  1. You need functionality that is not yet implemented in the RDA5807 library.
  2. You want to modify the behavior of an existing function.

The code below shows these tow situations.

#include <RDA5807.h>
class MyCustomRDA5807 : public RDA5807 {  // extending the original class RDA5807

private: 
  // Implements some specific members and methods to the new class if necessary
  uint16_t up_limit, down_limit;

  void getBandLimits() { 
    if (this->getBand3Status() == 0) {
      up_limit = 6500;
      down_limit = 5000;
    } else {
      up_limit = this->endBand[this->currentFMBand];
      down_limit = this->startBand[this->currentFMBand];
    }
  }

public:
  // Implements some new members functions to the new class
  int getSoftBlendEnable() {  // A RDA5807 command that PU2CLR RDA5807 Arduino Library does not implement
    rda_reg07 tmp;
    tmp.raw = this->getDirectRegister(0x07).raw;
    return tmp.refined.SOFTBLEND_EN;
  }

  uint16_t getDeviceInfo() {  // another RDA5807 command that PU2CLR RDA5807 Arduino Library does not implement
      rda_reg00 tmp;
      tmp.raw = this->getDirectRegister(0x00).raw;
      return tmp.refined.HIGH_CHIP_ID;
  }

  // Overwriting parent method setFrequencyUp - Chenging the behavior of the setFrequencyUp function
  void setFrequencyUp() {
    getBandLimits();
    if (this->currentFrequency < up_limit)
      this->currentFrequency += (this->fmSpace[currentFMSpace]);
    else
      this->currentFrequency = down_limit;

    setFrequency(this->currentFrequency);
  }

  // Overwriting parent method setFrequencyDown - Chenging the behavior of the setFrequencyDown function
  void setFrequencyDown() {
    getBandLimits();
    if (this->currentFrequency > down_limit)
      this->currentFrequency -= (this->fmSpace[currentFMSpace]);
    else
      this->currentFrequency = up_limit;

    setFrequency(this->currentFrequency);
  }
};

MyCustomRDA5807 radio;  // the instance of your custom class based on RDA5807 class

void setup() {
  Serial.begin(9600);
  while (!Serial);
  Serial.println("Customizing RDA5807 class example.");
  radio.setup();
  radio.setFrequency(10390);
  Serial.println(radio.getSoftBlendEnable());
  Serial.println(radio.getDeviceInfo());
  radio.setBand(3);
  radio.setBand3_50_65_Mode(0);
}

void loop() {

  radio.setFrequency(6500);
  Serial.println(radio.getFrequency());
  delay(2000);
  radio.setFrequencyUp();  // Go to 50 MHz
  Serial.println(radio.getFrequency());
  delay(2000);
  radio.setFrequencyDown();  // Go to 65 MHz
  Serial.println(radio.getFrequency());
  delay(2000);
}

By adopting this approach, all you need to do is download the latest version of the PU2CLR RDA5807 Arduino Library. Instead of using the original RDA5807 class directly, you can use your own class that extends it. This ensures that you always have a version of the library tailored to your needs, without requiring additional work when updating the PU2CLR RDA5807 Arduino Library. In other words, your custom code will always be synchronized with the latest version of the PU2CLR RDA5807 Arduino Library.

Please, see the Sketches RDA5807_90_EXTENDING_CLASS and RDA5807_91_EXTENDING_CLASS for more details.

See also:

Thanks

See also

More Arduino Projects developed by author

References

Videos about RDA5807 and this Arduino Library