Mixer bluetooth -- 2

What we have:

5 microphones (or line-input) (3.5' male jack connection) (or more for next release)

2 stereo speakers (3.5' male jack connection) (or more for next release)

Bluetooth device ready to communicate by app. (Take as reference a typical mobile phone with an Android version greater than 5.1 (Lollipop) install on it)

What we need:

1. Record sound from microphones and play it by Speakers in a "live" situation ( = very low latency system).

2. Apply some effects to microphones in terms of GAIN and Frequency on each channel input/output

a. WARNING: Gain could be also negative (reverse wave) in order to create a special sound effect.

b. On frequency, in octave band, we need to put (typical) filter like low pass band or high pass band, band equalizer …etc…

3. Play by Speakers the mixed sound with these possibilities:

a. Speaker 1 or 2 could play a combination of sound among the 5 MICs (so we can play MIC 1 and MIC 2 or all MICs or 3 of them and so on) independently. This meaning that we can also play MIC1 and MIC2 on Speaker 1 and MIC3 and MIC5 on Speaker 2 while MIC 4 is off, for example.

b. On each Speaker we can apply a sum of effects like to microphone. These effects can be set differently on each speaker.

4. All these settings are digital, so we need to record the sound, apply effects and choose what is played and what is not by Bluetooth interface in live mode.

Final release of electronic board need also to have:

1. Bluetooth communication on board (as wireless monitor and firmware upgrading).

2. COM port by mini USB female connection (as wired monitor and firmware upgrading).

3. I2C communication port using a RJ45 connector (following the specifications in a document apart) for compatibility to another system.

4. At least n°5 3.5' Jack female connection for the microphones (or more for next release).

5. At least n°2 3.5' Jack female connection for the speakers (or more for next release).

6. 1 connector for 230V power supply.

Minimal constrain:

1. No interference (noise) between the power supply and the sound play by speakers or recorded by microphones. (= EMC compatibility)

2. No interference (noise) between Bluetooth and the sound play by speakers or recorded by microphones. (= EMC compatibility)

3. CPU clock frequency MUST BE FAST enough to avoid problems on latency. DSP system with same constrains is needed also.

4. An SD card used to record sound could be take in consideration but need to be a fast record type.

Is up to you define a list of tecs specs of microphone and speaker compatible with hardware you are design.

Electronic Design Микроконтроллер PCB Design and Layout

ID проекта: #24398557

О проекте