Difference between revisions of "Microduino-Module AudioPro"

Microduino-AudioPro

Microduino AudioPro is a multifunctional audio module, with VS1053 as the decoder, integrating 2.2W stereo amplifying, and supporting 2.5mm stereo earphone interface and MIDI function.

Features

• Support multiple formats of decoding：MP3/WMA/AAC/WAV/Ogg Vorbis/MIDI.
• Can real-time imitate as much as 128 kinds of MIDI instruments.
• Integrate 2.2w stereo amplifier.
• With 2.5mm stereo earphone interface onboard.
• Earphone/extroverted automatic switch over function.
• SPI high-speed communication interface.
• Small, cheap, stackable and open;
• Open-source hardware circuit design, and compatible-with-Arduino programming development environment;
• Unified Microduino interface specification and abundant periphery modules, which can be quickly extended and connected with other modules and sensors which meet the Microduino interface specification, conveniently and flexibly;
• 2.54-spacing mother line interface is convenient for integration to the pegboard.

Specification

• Support multiple formats of decoding: MP3/WMA/AAC/WAV/Ogg Vorbis/MIDI
• Can real-time imitate as much as 128 kinds of MIDI instruments.
  • Universal MIDI and file 0 in SP‐MIDI format can be played, and files in format 1 and 2 must be transformed into format 0 by the users.
  • Number of polyphony is 64 at most, and the number of polyphony that can continue at most is 40.

• Integrate 2.2w stereo amplifier（LM4863）
  • Can control the enable through the GPIO4 of VS1053.
• With 2.5mm stereo earphone interface onboard.
• Earphone/extroverted automatic switch over function.
• 18-bit oversampling, multi-bit, sigma‐delta type high-precision DAC
  • Oversampling generally refers to higher sampling rate several times than the nominal sampling rate, and it is commonly used to improve the sampling accuracy. It means when restore the digital sound, use sampling rate several times higher than the nominal sampling rate to output, which can make the abrupt of the ladder of the audio flatten out, to lower the digital background noise and reduce the distortion, thereby get high-quality audio surpassing the effect of the original sampling rate outputting.

• SPI high-speed communication interface

• Electrical specification
  • VS1053: 3.3V, 30~60mA
  • LM4863: 5V, 1A

Introduction of Pins

• Pin D2 is real-time MIDI interface.
  • Real-time MIDI is not enabled by default. If you want to enable it, just short connect the jumper on the back of the module.
  • After enabling the real-time MIDI, the baud rate of UART should be 31250bps, and SPI interface at this time can't be used.

Microduino-AudioPro Spec

Documents

• Eagle SCH：File:AudioPro.pdf
• Materials of module vs1053(Chinese)：File:Vs1053 cn.pdf
• Materials of module vs1053(English)：File:Vs1053.pdf

Development

• You can implement the function test through _06_Microduino_AudioPlus_VS1053 library: github
• The relevant sample programs to download：github
  • Audio_MIDI during them is the sample program that the SPI interface real-time realizes MIDI through loading patches.
  • Audio_ROM during them is the sample program to play the audio files in ROM.
• The material of MIDI can be seen in the Appendix.
• Tool for the hexadecimal to audio files：File:DataToHex.zip

Application

FAQ

History

Gallery

Microduino-AudioPro TOP

Microduino-AudioPro BUT

Video

Appendix

MIDI numbers,Note names and frequencies

You can refer to：NUSW

MIDIlist

Note names, MIDI numbers and frequencies are related here in tables and via an application that converts them. The musical interval between two notes depends on the ratio of their frequencies. An octave is a ratio of 2:1 and, in equal temperament, an octave comprises 12 equal semitones. Each semitone therefore has a ratio of 21/12 (approximately 1.059). By convention, A4 is often set at 440 Hz. These data were used to calculate the first table below, which gives the frequency of any standard keyboard note or MIDI note number. To convert from any frequency to pitch (i.e. to the nearest note and how far it is out of tune). This table is reproduced inverted below, i.e. with high pitch at the top. To convert from any frequency to pitch (i.e. to the nearest note and how far it is out of tune, go to the frequency to note converter written by Andrew Botros. How to do the calculation? Suppose that two notes have frequencies f1 and f2, and a frequency ratio of f2/f1. An octave is a ratio of 2:1, so the number of octaves between f2 and f1 is no = log2(f2/f1). Now to divide the octave into smaller units. In equal temperament, where all semitones have the same frequency ratio of 21/12, conversion between note name and frequency is simple. First, one needs a reference note and frequency. This is usually A4, which is often set at 440 Hz. For a note that lies n semitones higher (or −n semitones lower), the frequency is then fn = 2n/12*440 Hz. Conversely, one can obtain n, the number of semitones from A4, from n = 12*log2(fn/440 Hz). Similar equations give no, the number of octaves from A4, and nc, the number of cents from A4: no = log2(fn/440 Hz) and nc = 1200*log2(fn/440 Hz). In electronic music, pitch is often given by MIDI number: let's call it m for our purposes. m for the note A4 is 69 and increases by one for each equal tempered semitone, so this gives us a simple conversion between frequencies and MIDI numbers (again using 440 Hz as the pitch of A4): m = 12*log2(fm/440 Hz) + 69 and fm = 2(m−69)/12(440 Hz). The notation used here is not universal: in German speaking countries, H is used instead of B, and B is used for Bb. (This allowed Bach to write his name in the Art of Fugue.) And of course when different tuning systems are used, different names are applied.

MIDI Melody Instruments Group(GM1)

MIDI Percussion Instruments Group(GM1+GM2)