data.rb

require "serialport"
require "em-websocket"
require "json"

serial = SerialPort.open("/dev/cu.usbmodem1411")

# while data = serial.gets
#   raw = data.chomp
#   p raw
# end

EM.run do
  EM::WebSocket.run(host: "0.0.0.0", port: 1666) do |ws|
    EM.defer do
      filter = Array.new(4, 0)
      
      while data = serial.gets(";")
        raw = data.chomp
        # p raw
        values = raw.split(",").map { |value| value.to_i >= 10 }
        next if values.size != 4
        
        message = values.each_with_index.map do |active, i|
          if active
            filter[i] = [filter[i] + 1, 3].min
          else
            filter[i] = [filter[i] - 2, 0].max
          end
          
          filter[i] >= 2
        end.to_json
        
        p filter
        
        begin
          ws.send message
        rescue => e
          p e.message
        end
      end
    end
  end
end