Transports

Transport implementations Kv4pRadio can be constructed with.

class kv4p.transports.Kv4pTransport

Bases: object

Documents the interface Kv4pRadio needs from a transport.

Not enforced via abc/@abstractmethod on purpose: the shape a future Bluetooth transport needs isn’t known yet, and a formal contract would just be a breaking change waiting to happen. Subclass and implement.

open(on_frame, on_error=None)

Open the transport and start delivering incoming KISS frames to on_frame.

on_error is called (from the transport’s own background thread, if it has one) when the connection is lost unexpectedly, e.g. a disconnected USB cable or a device reboot mid-read. It is not called on a normal close().

Parameters:

• on_frame (Callable[[int, bytes], None])

• on_error (Callable[[Exception], None] | None)

Return type:

None

close()

Close the transport.

Return type:

None

write_frame(command, payload)

Write one KISS frame.

Parameters:

• command (int)

• payload (bytes)

Return type:

None

flush()

Wait until pending output is written.

Return type:

None

reset()

Reset the radio so it re-announces itself via HELLO.

Return type:

None

Serial Transport

class kv4p.transports.serial.Kv4pSerialTransport(device, baudrate)

Bases: Kv4pTransport

Blocking serial transport with an RX thread, for use with Kv4pRadio.

Parameters:

• device (str)

• baudrate (int)

__init__(device, baudrate)

Parameters:

• device (str)

• baudrate (int)

Return type:

None

open(on_frame, on_error=None)

Open serial port and start the RX thread.

Parameters:

• on_frame (Callable[[int, bytes], None])

• on_error (Callable[[Exception], None] | None)

Return type:

None

close()

Stop RX thread and close serial port.

Return type:

None

reset()

Hardware-reset the ESP32 into its normal firmware via an RTS pulse.

DTR is held deasserted throughout so GPIO0 stays in run mode (not bootloader mode); RTS is pulsed to toggle EN/CHIP_PU.

Return type:

None

write_frame(command, payload)

Write one KISS frame.

Parameters:

• command (int)

• payload (bytes)

Return type:

None

flush()

Wait until serial output is written.

Return type:

None

Dummy Transport

class kv4p.transports.dummy.DummyTransport(*, firmware_version=17, window_size=2048, min_radio_freq=134.0, max_radio_freq=174.0, features=0, device_state_flags=0)

Bases: Kv4pTransport

Transport with no real radio: answers reset() with a synthetic HELLO.

Parameters:

• firmware_version (int)

• window_size (int)

• min_radio_freq (float)

• max_radio_freq (float)

• features (int)

• device_state_flags (int)

__init__(*, firmware_version=17, window_size=2048, min_radio_freq=134.0, max_radio_freq=174.0, features=0, device_state_flags=0)

Parameters:

• firmware_version (int)

• window_size (int)

• min_radio_freq (float)

• max_radio_freq (float)

• features (int)

• device_state_flags (int)

Return type:

None

open(on_frame, on_error=None)

Open the transport and start delivering incoming KISS frames to on_frame.

on_error is called (from the transport’s own background thread, if it has one) when the connection is lost unexpectedly, e.g. a disconnected USB cable or a device reboot mid-read. It is not called on a normal close().

Parameters:

• on_frame (Callable[[int, bytes], None])

• on_error (Callable[[Exception], None] | None)

Return type:

None

close()

Close the transport.

Return type:

None

reset()

Reset the radio so it re-announces itself via HELLO.

Return type:

None

write_frame(command, payload)

Write one KISS frame.

Parameters:

• command (int)

• payload (bytes)

Return type:

None

flush()

Wait until pending output is written.

Return type:

None