Soundboard with Az-Nano V3 and DFPlayer Mini

A soundboard is a popular tool that is used in particular in television programs or live productions for accompanying acoustic effects. By pressing a button, sounds or noises can be played directly in advance, which enables quick and intuitive use. This functionality is mainly used in entertainment formats to loosen up reports, sketches or moderations and offer the audience an appealing experience.

The idea: Pressing one of the keys connected to the microcontroller is played with a corresponding sound file that was previously saved on an SD card via a DFPlayer module. Each button is assigned in the program of a specific file.

The DFPlayer plays a central role because it makes it possible to reproduce sounds in high quality with minimal hardware effort. The Nano serves as a control center that hits the selection of the sounds based on the pressed buttons and sends the corresponding control commands to the DFPlayer.

Construction of the circuit

• Dfplayer mini:The DFPlayer is via RX and TX with the Nano tied together, to the RX-PIN is connected to a 1kOhm resistance between the DFPlayer and microcontroller to ensure trouble -free operation. In addition, there is a connection to the power supply (5 V and GND). The loudspeaker is connected directly to the DFPlayer.
• Buttons and resistance:Each button is connected to its own digital pin of the microcontroller, while the other side is connected to mass (GND).The internal pull-up resistors are activated in the program, which means that no further resistors are necessary.
• Power supply:The microcontroller and the DFPlayer share the power supply in most cases. A USB connection or a battery via VIN PIN can be used here.

The structure on a cover board is ideal for the beginning to test the functionality and simply fix incorrect connections.📷

Software

Programming the board

The heart of the project is the software. The Nano is programmed to identify every key pressure and control the DFPlayer accordingly.

Preparation

• Download the Arduino Ide from the official Website down.
• Install the libraries: Dfplayer_mini_mp3 and Software. These are necessary for communication between the microcontroller and the DFPlayer. The libraries can be downloaded and installed with the internal library management.
• A driver for the CH340 chip is necessary for communication with the microcontroller via USB. This can after following instructions be installed.

Sample code

Download the following code By choosing the right board (Arduino Nano | ATMEGA328P) and real serial COM port (see device manager) on the microcontroller:

#including "Arduino.h"#including "Softwareerial.H"#including "DfrobotdfPlayermini.h"// pins#define Dfplayer_rx 10#define Dfplayer_tx 11// initialize the dfplayer and communicationSoftware myserial (dfplayer_tx, dfplayer_rx);Dfrobotdfplayermini MyDFPlayer;// array for buttons pinsintimately Button pins [] = {2, 3, 4, 5};void set up() { // serial monitor for debugging Serial.Begin(9600); // start dfplayer Myserial.Begin(9600); IF (! Mydfplayer.Begin(myserial)) { Serial.print("No DFPlayer Mini found!"); while (True); } Serial.print("Dfplayer Mini ready!"); // Define pins for buttons for (intimately I = 0; I < 4; I ++) { pin mode(Button pins [i], input_pullup); }}void loop() { for (intimately I = 0; I < 4; I ++) { IF (digital read(Button pins [i]) == Low) { mydfplayer.play (i + 1); // sound 1 to 10 delay(500); // depressing } }}

You can under this link download.

Prepare the SD card

Format the SD card in the FAT32 format. The sound files, e.g. in MP3 or WAV format, must be transferred to the SD card before use. It is important that they are numbered ascending before copying and renamed them accordingly so that the DFPlayer can access them correctly. Name the files according to the following scheme:

● `0001.mp3`

● `0002Name.mp3`(Description can be inserted optionally after numbering)

● `0003.mp3`

● etc.

Important: All files must be transferred to the SD card in a single copy process. If this is not observed and the files are copied one after the other or in several steps, the internal file name can be changed By the file system, which could lead to undesirable behavior.

Important: All files must be transferred to the SD card in a single copy process. If this is not observed and the files are copied one after the other or in several steps, the internal file name can be changed By the file system, which could lead to undesirable behavior.

Testing the function

After uploading the code and inserting the SD card, you can test the soundboard. Press a button and check whether the corresponding sound is played.

With the command mydfplayer.volume (30); the volume can be set, 30 is the maximum volume.

Housing

After testing the project on the Breadboard, you can finally go to a 3D-Build printed housing. The button is suitable as a button as a replacement for the previous microphone buttons, as they can simply be screwed into the housing.Print the.STL Files (Soundboard3d.stl,Soundboard3dtop.stl) with a 3D printer and assemble the button in the lid. You can solve the electronics to the 5x7 cm PCB with corresponding box strips. A 9V block battery on the VIN and GND connection can be closed to the power supplyn und are placed in the housing.

You are welcome to expand the project according to your ideas. For adjustments to the housing, they stand Raw files (Soundboard3d.fcstd,Soundboard3dtop.fcstd) available. This can be individually edited in Freecad, a free open source program.