@spec close(port()) :: :ok

Closes a UDP socket opened with open/1.

Parameters

• socket (port()) — socket from open/1

Returns

Always :ok.

Examples

:ok = Drone.Adapters.Tello.Connection.close(socket)

@spec default_drone_ip() :: :inet.ip_address()

Default Tello station IP address.

Returns

:inet.ip_address() — {192, 168, 10, 1}.

Examples

{192, 168, 10, 1} = Drone.Adapters.Tello.Connection.default_drone_ip()

@spec default_drone_port() :: pos_integer()

Default Tello command UDP port.

Returns

8889.

Examples

8889 = Drone.Adapters.Tello.Connection.default_drone_port()

@spec default_local_port() :: pos_integer()

Default local UDP bind port.

Returns

8889.

Examples

8889 = Drone.Adapters.Tello.Connection.default_local_port()

@spec default_timeout() :: pos_integer()

Default command reply timeout in milliseconds.

Returns

10_000.

Examples

10_000 = Drone.Adapters.Tello.Connection.default_timeout()

@spec open(keyword()) :: {:ok, port()} | {:error, term()}

Opens a passive UDP socket bound to the local port.

Parameters

• opts (keyword()) — optional:
  • :local_port (non_neg_integer()) — bind port (default 8889)

Returns

• {:ok, port()} — open :gen_udp socket (active: false)
• {:error, term()} — bind failure (for example :eaddrinuse)

Examples

{:ok, socket} = Drone.Adapters.Tello.Connection.open(local_port: 0)
:ok = Drone.Adapters.Tello.Connection.close(socket)

@spec receive_response(port(), non_neg_integer()) ::
  {:ok, binary()} | {:error, term()}

Receives one UDP datagram from the Tello (or times out).

Charlist payloads from older OTP paths are converted to binaries.

Parameters

• socket (port()) — open UDP socket in passive mode
• timeout (non_neg_integer()) — milliseconds to wait

Returns

• {:ok, binary()} — reply bytes
• {:error, :timeout} — no packet received
• {:error, term()} — other :gen_udp.recv/3 errors

Examples

{:ok, data} = Drone.Adapters.Tello.Connection.receive_response(socket, 5_000)
{:error, :timeout} =
  Drone.Adapters.Tello.Connection.receive_response(socket, 1)

@spec send_command(port(), String.t(), keyword()) :: {:ok, term()} | {:error, term()}

Sends a command string and waits for one UDP reply.

Parameters

• socket (port()) — open UDP socket
• command (String.t()) — ASCII SDK command (from Drone.Adapters.Tello.Encoder.encode/1)
• opts (keyword()) — optional:
  • :drone_ip (:inet.ip_address()) — default {192, 168, 10, 1}
  • :drone_port (non_neg_integer()) — default 8889
  • :timeout (non_neg_integer()) — recv timeout ms (default 10_000)

Returns

• {:ok, binary()} — raw reply payload (not yet parsed)
• {:error, :timeout} — no datagram within the timeout
• {:error, term()} — send or socket failure

Examples

{:ok, reply} =
  Drone.Adapters.Tello.Connection.send_command(socket, "battery?",
    timeout: 3_000
  )

{:ok, percent} = Drone.Adapters.Tello.Parser.parse(reply)