# seeed-voicecard

The drivers for [ReSpeaker Mic Hat](https://www.seeedstudio.com/ReSpeaker-2-Mics-Pi-HAT-p-2874.html), [ReSpeaker 4 Mic Array](https://www.seeedstudio.com/ReSpeaker-4-Mic-Array-for-Raspberry-Pi-p-2941.html), [6-Mics Circular Array Kit](), and [4-Mics Linear Array Kit]() for Raspberry Pi.

### Install seeed-voicecard
Get the seeed voice card source code and install all linux kernel drivers
```bash
git clone https://github.com/respeaker/seeed-voicecard
cd seeed-voicecard
sudo ./install.sh
sudo reboot
```
It may probably happen that the driver won't compile with the latest kernel when raspbian rolls out new patches to the kernel. If so, please try `sudo ./install.sh --compat-kernel` which uses an older kernel but ensures that the driver can work. 

## ReSpeaker Documentation

Up to date documentation for reSpeaker products can be found in [Seeed Studio Wiki](https://wiki.seeedstudio.com/ReSpeaker/)!
![](https://files.seeedstudio.com/wiki/ReSpeakerProductGuide/img/Raspberry_Pi_Mic_Array_Solutions.png)


### Coherence

Estimate the magnitude squared coherence using Welch’s method.
![4-mics-linear-array-kit coherence](https://user-images.githubusercontent.com/3901856/37277486-beb1dd96-261f-11e8-898b-84405bfc7cea.png)  
Note: 'CO 1-2' means the coherence between channel 1 and channel 2.

```bash
# How to get the coherence of the captured audio(a.wav for example).
sudo apt install python-numpy python-scipy python-matplotlib
python tools/coherence.py a.wav

# Requirement of the input audio file:
- format: WAV(Microsoft) signed 16-bit PCM
- channels: >=2
```

### uninstall seeed-voicecard
If you want to upgrade the driver , you need uninstall the driver first.

```
pi@raspberrypi:~/seeed-voicecard $ sudo ./uninstall.sh 
...
------------------------------------------------------
Please reboot your raspberry pi to apply all settings
Thank you!
------------------------------------------------------
```

Enjoy !

### FAQ

When you encounter any installation and use problems when you start your ReSpeaker Pi hat, please use the following image for testing. We have installed seeed-voicecard based on the latest PI image, which can be used by burning it directly on SD. If this still cannot solve your problem, you can ask in the issue. We will try our best to solve your problem.