/*

• Title: suffrage
• Author: Richard Thai and Garrick Merrill
• Created: 12/16/2010
• Modified: 2/22/2011
• Prerequisite: IMPORTANT! The IXM's that download this code MUST have an
• integer ID programmed in beforehand. Use the IXM BIOS to set the board
• NAME ((n=NAME) according to the help menu). Note that the input is stored
• on the boards in base-36 so that it can accept letters in addition to
• integers (26 letters + 10 integers = 36 symbols). You don't need an
• 'integer' ID, but it's certainly a good idea since the IXM's are typically
• shipped with a unique 8 digit identifying sticker.
• Info on accessing the BIOS can be found in the Antipasto Hardware Wiki on
• http://antipastohw.pbworks.com/w/page/30205779/IXM-Bios-Tutorial.
• Description: This is a demonstration of the redundant qualities of the IXM.
• Each board performs the same calculation (finding the n_th prime number) and
• casts its answer as a vote within its interval-ping (heart-beat). All votes
• are distributed among the connected boards and a majority is determined with
• every new vote. Each board then recognizes the status of the grid (majority,
• minority, or tie) and lights up its green, red or no LED respectively. A
• blue LED lights up to signify that it is currently processing (if you can
• catch it, it's rather fast).
• Button Function:
• To simulate incorrect answers, the button on
• the IXM can be pressed the adjust what the affected IXM calculates. In this
• case, the "incorrect" calculation is for the (n + 1)_th prime instead of the
• n_th prime.
• Terminal Commands:

• x - force a reboot to all IXM's in the grid

• t - request to stop sending heart-beat packets (starts with "r"

• followed by a combination of numbers and commas) and to start
• displaying the local IXM's internal table which will update on
• an interval

• cN - request to initiate a calculation for the N_th prime to all

• IXM's within the grid. The vote for said calculation will be
• broadcast the moment it is generated. Replace the 'N' with
• the N_th prime to calculate, for example: c15 is a request to
• calculate the 15th prime. There is a limit programmed within
• the boards as to how high of a prime they can take which can be
• found within the header file as "PRIME_THRESHOLD" and
• "PRIME_ARR_THRESHOLD" which is the prime sequence and the prime
• value plus one, respectively. Change those for higher primes!
• Notes:
• The boards do not rely on a slave/master setup, meaning that every internal
• could potentially be different. A weakness is that IXM(s) in the grid could
• have discordant data. However, this setup also allows IXM's to have no single
• point of failure should an arbitrary board encounter a data/network fault
• (assuming grid with redundant networking paths).
• As the amount of IXM's increase, data and networking redundancy increase:
• • 2+ boards allow a consensus to be made
• • 3+ boards allow an incorrect vote to be determined
• • 4+ boards (in grid formation) ensure that a single failed board will
• not disrupt data paths for remaining boards */