CRC16 calculation in Elixir using constant 0xA001

crc16.ex

defmodule CRC16 do
	use Bitwise	
	@constant 0xA001	

	def calculate(data) do
		crc = 0x0000
		table = init_table()
		:binary.bin_to_list(data)
		|> Enum.reduce(crc, fn(value, crc) ->
			(crc >>> 8) ^^^ Enum.at(table, (crc ^^^ value) &&& 0x00ff)
		end)
	end

	defp init_table() do
		Enum.map(0..255, fn(i) ->
			Enum.reduce(0..7, i, fn(_, crc) ->
				case crc &&& 0x0001 do
					0x0001 -> (crc >>> 1) ^^^ @constant
					_ -> crc >>> 1
				end	
			end)
		end)
	end
end

data = File.read! "filu.bin"
crc = Integer.to_string(CRC16.calculate(data), 16)
IO.puts("CRC is #{crc}")

Hi, does this implementation works correctly? Can you tell me what is the type of input that you are using for this? (an example input would be great!). Thanks.

Hi,

Sorry for the late reply. Github doesn't notify gist's comments so I didn't notice your comment until now.

This should work correctly. I have tested it against other implementations (e.q. https://github.com/cristianav/PyCRC) and it returned same value. Input type is a binary data object. Any normal file or even strings when converted to binary, can be used as an input.