@spec decode_ascii(integer() | [integer()]) :: {:ok, binary()}

Decode integer value(s) representing ASCII characters to text

• Up to 2 ASCII characters are stored per register.
• 0 is interpreted as a terminator.

Examples

iex> decode_ascii(18537)
{:ok, "Hi"}

iex> decode_ascii([18537, 8448, 0])
{:ok, "Hi!"}

@spec decode_boolean(integer()) :: {:ok, boolean()} | {:error, binary()}

Interpret 1 as true and 0 as false

Examples

iex> decode_boolean(0)
{:ok, false}

iex> decode_boolean(1)
{:ok, true}

@spec decode_signed_int(integer()) :: {:ok, integer()}

Decode value to a signed integer.

Examples

iex> decode_signed_int(77)
{:ok, 77}

iex> decode_signed_int(65_535)
{:ok, -1}

@spec decode_unsigned_int(non_neg_integer()) :: {:ok, non_neg_integer()}

Decode value to an unsigned integer.

Examples

iex> decode_unsigned_int(65_535)
{:ok, 65_535}

@spec encode_ascii(binary(), ModBoss.Encoding.Metadata.t()) ::
  {:ok, [integer()]} | {:error, binary()}

Encode text to integers representing ASCII characters.

• Prepares zero or more characters to be stored in contiguous registers.
• Up to 2 ASCII characters can be stored per register.
• 0 is used as a terminator if fewer than the maximum characters are encoded.
• The ModBoss.Mapping is required in order to determine how many characters are supported.

Examples

iex> metadata = %ModBoss.Encoding.Metadata{type: :holding_register, address_count: 3}
iex> encode_ascii("Hi!", metadata)
{:ok, [18537, 8448, 0]}

iex> metadata = %ModBoss.Encoding.Metadata{type: :holding_register, address_count: 1}
iex> {:error, reason} = encode_ascii("Hi!", metadata)
iex> String.match?(reason, ~r/Too many characters/)
true

@spec encode_boolean(boolean()) :: {:ok, integer()} | {:error, binary()}

Encode true as 1 and false as 0

Examples

iex> encode_boolean(true)
{:ok, 1}

iex> encode_boolean(false)
{:ok, 0}

@spec encode_signed_int(integer()) :: {:ok, integer()} | {:error, binary()}

Encode value as a signed integer.

Valid values are -32,768 to 32,767.

This function assumes the expected output is a regular Elixir integer. It simply provides a guard against overly large values, then returns the provided value.

Examples

iex> {:ok, -32_768} = encode_signed_int(-32_768)
iex> {:error, _too_large} = encode_signed_int(32_768)

@spec encode_unsigned_int(non_neg_integer()) ::
  {:ok, non_neg_integer()} | {:error, binary()}

Encode value as an unsigned integer.

Valid values are 0 to 65,535.

This function assumes the expected output is a regular Elixir integer. It simply provides a guard against overly large values, then returns the provided value.

Examples

iex> {:ok, 65_535} = encode_unsigned_int(65_535)
iex> {:error, _too_large} = encode_unsigned_int(65_536)