The Handy Board has a USB-serial interface for communications with the host computer.
The USB Interface has similar features as the original Serial Interface:
- RJ11 telephone-style cable to connect to Handy Board
- trickle and rapid charge modes for Handy Board’s built-in nicad battery
- charge circuit powered by external 12v, 500mA DC adapter
It also provides communications with the Handy Board via the USB connection. The board has a driver chip from FTDI; download the “VCP” (virtual COM port) driver for your operating system (Windows, Mac, or Linux) from http://www.ftdichip.com/Drivers/VCP.htm.
Here is a schematic of the USB Interface Board. In addition to connecting to the Handy Board’s serial communications lines, the USB board also provides 0.1” headers for connecting to your own TTL-level serial circuit. Pads for supplying +5v, ground, TxD, and RxD are available.