eversan_serial_sync.rb

# Copyright 2011, 2014 Exavideo LLC.
# 
# This file is part of Exaboard.
# 
# Exaboard is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# Exaboard is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with Exaboard.  If not, see <http://www.gnu.org/licenses/>.

require_relative './serial_sync_helper'

##
# Parser for Eversan serial data stream
#
# This class implements a parser for the serial data stream available from
# some Eversan scoreboard consoles. This data stream is transmitted as RS-422
# at a non-standard baud rate, so some external hardware is needed to make 
# the data useful. Some consoles have the RS-422 port installed but are
# missing the driver chip. For these units, jumper wires may be installed 
# in place of the driver chip, making the port into a TTL-level serial output.
# An AVR C program is provided in hw_interface/eversan.c; this program
# translates the Eversan serial output to standard 115200bps 8N1 serial
# when run on appropriate hardware.
#
# The Eversan protocol is fairly simple: a string of digits is periodically
# transmitted. These digits correspond to the digits displayed in various
# locations on the scoreboard. The Eversan scoreboard that this code was 
# developed for was a simple model, displaying time, period, and score,
# so that's all it's able to sync. Given the protocol's simplicity, it 
# shouldn't be too difficult to extend this to work with more complex models.
class EversanSerialSync

	include SerialSyncHelper

	##
	# Initialize the Eversan serial stream parser.
	#
	# The parser will report its data to +app+. +options+ is a hash
	# of options, including:
	#
	# [+'port'+]        serial port to use
	def initialize(app, options)
		@app = app
		@stop_thread = false

		@sp = open_port(options, 115200)
		@sp.read_timeout = 500
		@thread = Thread.new { run_thread }
	end

	##
	# Shut down the Eversan parser and free the serial port.
	def shutdown
		STDERR.puts "Eversan serial sync thread shutting down"
		@stop_thread = true
		@thread.join
		@sp.close
		STDERR.puts "Eversan serial sync thread terminated"
	end

	##
	# Return the types of data that can be supplied by the parser.
	def capabilities
		['clock', 'score']
	end

	##
	# Parse the string of digits sent by the scoreboard, and send the data
	# to the app.
	def parse_digit_string(string)
		if string =~ /(\d{2})(\d{2})(\d)(\d{2})(\d{2})(\d)$/
			minutes = $1.to_i
			seconds = $2.to_i
			tenths = $3.to_i
			hscore = $4.to_i
			vscore = $5.to_i
			period = $6.to_i

			clock_value = minutes * 600 + seconds * 10 + tenths
			@app.sync_clock_time_remaining(clock_value)
			@app.sync_clock_period(period)

			@app.sync_hscore(hscore)
			@app.sync_vscore(vscore)
		end
	end

	##
	# Read from the serial port, building a string of digits until a delimiter
	# is received. Then call +parse_digit_string+ to extract game data from
	# the received string.
	def run_thread
		begin
			STDERR.puts "Eversan serial sync thread starting"
			digit_string = ''
			digits = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
			while not @stop_thread
				ch = @sp.read(1)
				if ch
					if digits.include?(ch)
						digit_string += ch
					else
						parse_digit_string(digit_string)
						digit_string = ''
					end
				end
			end
		rescue Exception => e
			STDERR.puts e.inspect
		end
	end
end