Ben Blinkenlights
=================

This is an umbrella project for various items related to using the 8:10
card slot of the Ben Nanonote. The "flagship" sub-project is no longer
the top-level LED board but the Universal Breakout Board, in ubb/

  .		The original blinkenlights, a board with a line of LEDs
  cam/		Outline of the board; obsolete
  ext/		UBB variant with ground between signals; obsolete
  ioscript/	GPIO test pattern generator; experimental
  libubb/	Helper functions for accessing UBB
  lpc111x-isp/	In-system programmer for NXP LPC111x MCUs
  nxuart/	Card with ATmega48 in UART configuration; incomplete
  swuart-chat/	Software-implemented UART (on UBB)
  ubb-usb/	Design for hypothetical UBB-based USB host
  ubb-vga/	VGA output using UBB and minimal circuitry
  ubb/		The Universal Breakout Board (UBB)


Blinkenlights
-------------

This project is a proof of concept implementation of Rikard Lindstrom's
idea of using the Ben's 8:10 card slot as a general extension interface
also for devices that don't speak MMC or SD/SDIO. The application is a
simple LED circuit, as suggested by David Samblas.

The 8:10 card slot gives access to six GPIOs, a 3.3 V supply that can
be switched on and off by software, and ground. We use a simple form of
multiplexing to drive ten LEDs with this interface.

Note that one should only light one LED at a time. If multiple LEDs are
lit, they will share the current though the common resistor, and will
thus be less bright than a single LED.