8-Bit Interface Board with USB Feature

The project is intended to operate with microcontroller boards by easily connecting a small USB 8-bit interface board.

The target microcontroller board should be supporting USB-powered and externally powered operation. There are 8 parallel data lines that the interface board can used to connect to the USB. A small internal FIFO and 4 handshake lines that comes with the interface which makes it appropriate to interface microcontroller designs to the USB. When the bitbang mode is enabled, it can be used as an 8-bit I/O and will produce the bits in chunks of 64 bytes with specified baud rate followed by a delay instead of coming out with a constant bit rate.

The required features such as direct flip-mounting on microcontroller board, connectors for all control & handshake lines, EEPROM configuration, power LED, USB-powered & self-powered operation, are retained while keeping the circuit as small as possible.

The Pins 1 & 2 on the SUPPLY pin header is connected externally when the board is used as USB-powered device while the Pin 1 is left open and Pins 2 & 3 is applied with 5V when the board is used as externally-powered device.

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