How can I communicate an Android Accessory with a USB Serial Port?

Question

Hereby the situation: I'm working on a Android Tablet that must work in Accessory mode. Reason why is because the tablet can't provide enough power to perform the communication with a Serial USB microcontroller and remain charging it's battery.

In order to achieve a successful communication, I must be able to set a few serial conditions for Modbus/RTU

• Serial Port Address (i.e. COM1, COM2...)
• Baud Rate (19200 bps)
• Data Bits (8)
• Stop Bits (1)
• Parity (None)

An excellent example in Delphi would be Modlink.

A good guidance would be UART https://github.com/ytai/ioio/wiki/UART

Meanwhile, I've found some useful projects but they were intended to work on Host mode.

https://github.com/mik3y/usb-serial-for-android https://github.com/ksksue/Android-USB-Serial-Monitor-Lite

I'm looking for any valuable information, guidance and references on how should I proceed to create an Android Application that can communicate with Serial USB.

How can I achieve this?

Note: I'm using Android Studio.

Answer 1

There's an excellent source code made by FTDI Chip, so if you ever need to perform USB/ftdi connections with Android try this application:

FTDI UART TERMINAL

Source code: http://www.ftdichip.com/Android.htm