* update faq

Author: lxowalle

docs/doc/en/faq.md

@@ -320,3 +320,6 @@ After that, open `http://<your_computer_IP>:8000/maixpy/index.html` in your brow
 
 Additionally, if you just want to save a single page for offline viewing, you can press `Ctrl + P` on that page and select "Print as PDF" to save the page as a local PDF file.
 
+## When recording is set to non-blocking mode, no audio data is captured
+
+When recording in non-blocking mode on MaixCam2, after starting recording, you need to wait for the audio data preparation to complete before being able to obtain the data. Therefore, there should be an interval between two recording operations. For example, if you need to record 60ms of audio data, you can call the recording function again every 50ms.

docs/doc/zh/faq.md

@@ -300,3 +300,7 @@ MaixCAM 自带的**相机**应用拍摄的照片和视频可以在自带的**相
 然后访问`http://电脑IP:8000/maixpy/index.html`即可离线查看文档。
 
 另外如果你只是想离线查看某一篇文档，你也可以在文档页面按`Ctrl+ P` 选择打印为 PDF 来保存单页面为 PDF到本地。
+
+## 录音时设置为非阻塞模式后, 录音没有数据
+
+MaixCam2在非阻塞模式下录音时, 开始录音后需要等待录音数据准备完成后才能拿到数据。因此两次录音之间需要间隔一段时间. 比如如果需要录入60ms的录音数据, 可以每50ms再调用一次录音函数.