#!/usr/bin/env ruby

a = "PUBX,41,1,0007,0003,19200,0"
b0 = "PUBX,41,0,0007,0001,115200,1"
b1 = "PUBX,41,1,0007,0001,115200,1"
b2 = "PUBX,41,2,0007,0001,115200,1"
c = "PUBX,41,0,0007,0001,57600,0"

def ex_or(a, b); return a ^ b; end

def checksum(array)
	res = array.shift
	while(array.size > 0)
		res = ex_or(res, array.shift)
	end
	return res
end

p checksum(a.unpack("c*")).to_s(16)
p checksum(b0.unpack("c*")).to_s(16)
p checksum(b1.unpack("c*")).to_s(16)
p checksum(b2.unpack("c*")).to_s(16)
p checksum(c.unpack("c*")).to_s(16)