Audio & BLE/SPP Pass-through Module Bluetooth 5.0 Wiki - DFRobot

Introduction

This Bluetooth module features Bluetooth/U-disk/TF-card playback, and Bluetooth call function, supporting simple and clear serial port control function, BLE pass-through, and SPP pass-through functions. The highlight of this product is the dual-mode Bluetooth, which also means that it can run the Bluetooth audio playback and data transmission at the same time, greatly reducing the development difficulty of embedded Bluetooth in other products.

Feature

Application

• Bluetooth Speaker with calling function
• Bluetooth Music Lamp
• MP3 Player

Specification

• Power Supply: 3.3V~5V
• Operating Current: 20mA
• Communication: UART
• Bluetooth: 5.0
• Operating Temperature Range: -40℃~80℃
• Operating Humidity Range: 5%RH~95%RH
• Dimension: 23*15.5mm/0.91*0.61”

Dimension Diagram

Board Overview

Tutorial

Note: it is recommended to use hardware serial to drive this module, since it may be unstable when using software serial, which may result in unknown errors.It is suggested to reduce the module's baud rate to 9600 when using software serial driver.

Requirements

• Hardware

  • DFRduino UNO R3 (or similar) x 1
  • BT401 x 1
  • Speaker with Amplifier
  • Dupont wires

• Software

  • Arduino IDE
  • Download and install the BT401 Library file and Sample Code (About how to install the library?)

Control by Arduino

API Function List

 /**
   * @brief Set volume
   * @param volume(0-30)
   * @return true or false
   */
  bool setVOl(uint8_t vol);

  /**
   * @brief Set working mode
   * @param eFunction_t
   * @return true or false
   */
  bool switchFunction(eFunction_t function);

  /**
   * @brief Set play mode 
   * @param ePlayMode_t
   * @return true or false
   */
  bool setPlayMode(ePlayMode_t mode);

  /**
   * @brief Play control  Only valid for playback by TF card and U-disk
   * @param ePlayControl_t
   * @return true or false
   */
  bool playControl(ePlayControl_t cmd);

  /**
   * @brief Next
   * @return true or false
   */
  bool next();

  /**
   * @brief Last 
   * @return true or false
   */
  bool last();

  /**
   * @brief Play the N-th file, play song of the specified number 
   * @param specified number
   * @return true or false
   */
  bool playSpecFile(uint16_t number);

  /**
   * @brief Play song of the specified path
   * @param specified path
   * @return true or false
   */
  bool playSpecFile(const char* path);

  /**
   * @brief Delete the currently playing file 
   * @return true or false
   */
  bool delCurFile();

  /**
   * @brief Dial a phone number 
   * @param phone number
   * @return true or false
   */
  bool callOut(const char* phoneNumber);

  /**
   * @brief Call control 
   * @param eControltalk_t
   * @return true or false
   */
  bool controltalk(eControltalk_t cmd);

  /**
   * @brief Obtain bluetooth status 
   * @return eBtStatus
   */
  eBtStatus getBtStatus();

  /**
   * @brief Obtain calling phone number 
   * @return phone number
   */
  String getTelNumber();

Sample Code 1- Playback

When the module powered on, enter the music mode, start playing the last recorded file, pause playing after 3S, play the next song after 3S, play the previous song after 3S, and play the first file copied into the device after 3 seconds.

/*!
 * @file playMusic.ino.ino
 * @brief Play song in TF card 
 * @n Experiment Phenomenon：play music and do the related actions 
 * @copyright  Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
 * @licence     The MIT License (MIT)
 * @author [Eddard](Eddard.liu@dfrobot.com)
 * @version  V1.0
 * @date  2020-12-29
 * @get from https://www.dfrobot.com
 * @url https://github.com/cdjq/DFRobot_ID809
*/

#include <DFRobot_BT401.h>
#include <SoftwareSerial.h>

SoftwareSerial btSerial(2, 3);  //RX TX

DFRobot_BT401 bt;

void setup(){
  btSerial.begin(115200);
  /*Delay 2s for the BT401 to start*/
  delay(2000);
  while(!bt.begin(btSerial)){
    Serial.println("Init failed, please check wire connection!");
    delay(1000);
  }
  bt.setVOl(30);
  bt.switchFunction(bt.eTFCard);
  bt.setPlayMode(bt.eDeviceCycle);
}

void loop(){
  //Play
  bt.playControl(bt.ePlay);
  delay(3000);
  //Pause 
  bt.playControl(bt.ePause);
  delay(3000);
  //Next 
  bt.next();
  delay(3000);
  //Last 
  bt.last();
  delay(3000);
  //Play song in the first file
  bt.playFileNum(1);
  while(1);
  /*Delete the currently playing file*/
  //bt.delCurFile();
}

Sample Code 2 - Incoming Call Control

/*!
 * @file answerCall.ino.ino
 * @brief Get incoming call information 
 * @n Experiment Phenomenon：Print phone number and answer the phone when a call comes 
 * @copyright  Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
 * @licence     The MIT License (MIT)
 * @author [Eddard](Eddard.liu@dfrobot.com)
 * @version  V1.0
 * @date  2020-12-29
 * @get from https://www.dfrobot.com
 * @url https://github.com/cdjq/DFRobot_ID809
*/

#include <DFRobot_BT401.h>
#include <SoftwareSerial.h>

SoftwareSerial btSerial(2, 3);  //RX TX

DFRobot_BT401 bt;

void setup(){
  Serial.begin(115200);
  btSerial.begin(115200);
  /*Delay 2s for the BT401 to start*/
  delay(2000);
  while(!bt.begin(btSerial)){
    Serial.println("Init failed, please check wire connection!");
    delay(1000);
  }
  bt.setVOl(30);
  bt.switchFunction(bt.eBluetooth);
}

void loop(){
    //If a call comes, print phone number and answer it 
    if(bt.getBtStatus() == bt.eCalling){
      Serial.println(bt.getTelNumber());
      delay(1000);
      //Answer
      bt.controltalk(bt.eAnswer);
      //Refuse to answer
      //bt.controltalk(bt.eRejectCall);
    }
    //If you are on the phone, print the incoming phone number 
    if(bt.getBtStatus() == bt.eOnphone){
      Serial.print("On the phone:");
      Serial.println(bt.getTelNumber());
      delay(1000);
      //Hang Up
      //bt.controltalk(bt.eHangUp);
    }
}

Connection

AT Command List

Note:

1. "\r\n is" omitted in all the commands below, and you need to add it to the end of the command in actual use. For example "AT+VOL=5\r\n", designate volume to "5".
   
2. Default serial baud rate: 115200
   

Volume Command

Control

Query

Working Mode Command

Control

Query

TF-card or U-disk Command

Control

Query

Bluetooth Audio Command

Control

Query

BLE Command

Control

BLE Query

Setting Command

Control

Most of the settings will take effect when repowering on the module.

Common Setting

Uncommon Setting

Query

BLE Pass-through

To use BLE Pass-through, please connect to BT401-BLE

SPP Pass-through

To use SPP Pass-through, please connect to BT401-AUDIO

FAQ

For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

More Documents