Android系统上如何使用UART串口

请参考谷歌说明：https://code.google.com/p/android-serialport-api/wiki/android_to_rs232_guideline。因为在国内上谷歌可能不太方便，所以如下直接把原文复制出来：

Introduction

Here is a page describing the different ways you could use to connect an Android device to an RS232 peripheral.

Solutions

Solution 1

• pros
  
  • No need for external API, the Android SDK provides the class BluetoothSocket
  • No need for hardware modifications
  • hardware flow control is supported
    
• cons
  
  • Bluetooth consume battery
  • high latency
  • low bandwidth
    
• API
  
  • Android SDK
    

Solution 2

• pros
  
  • USB to RS232 adapters are cheap and easy to find
  • no hardware modification needed
  • no external battery needed
  • low latency
  • high bandwidth
    
• cons
  
  • your Android device needs an USB host connector (most tablets have one, but phones usually don't)
  • your may need to root your device in order to change /dev/ttyUSB0 file permission, and to load a kernel module.
    
• API
  
  • android-serialport-api
    

Solution 3

• pros
  
  • The cheapest solution
    
• cons
  
  • hardware adapter must be built (http://www.instructables.com/id/Android-G1-Serial-Cable)
  • very few Android devices compatibles
  • hardware flow control is not supported (only RX/TX, no RTS/CTS signals)
    
• API
  
  • android-serialport-api
    

Solution 4

• pros
  
  • compatible with any Android device with an USB slave connector, i.e. 99.9% of the Android devices.
  • no need to root your phone
  • low latency
  • high bandwidth
  • you may use other GPIOs of the microcontroller at the same time
    
• cons
  
  • 
    
• API
  
  • https://github.com/ytai/ioio/wiki/UART