ydpg – basic YDPG-01 functions

Constants

Name	Value
ydpg.USB_DISCONNECTED	0
ydpg.USB_POWERED	1
ydpg.USB_CONNECTED	2
ydpg.USB_COM_PORT	3

Functions

ydpg.version()

Returns:

YDPG-01 firmware version.

Return type:

str

ydpg.serial()

Returns:

YDPG-01 serial number.

Return type:

str

ydpg.sync()

Flush file system cache to internal flash disc. Force saving of changed Gateway settings (NMEA 2000 address, etc.).

ydpg.busvoltage()

Can be used to detect the connection to NMEA 2000 network: busvoltage() > 7.

Minimum measurable voltage is 3V, maximum is 16V. Internal capacitor takes up to 10 seconds to self discharge if voltage is less than 7V.

Returns:

CAN bus voltage.

Return type:

float

ydpg.cputemp()

Returns:

MCU internal temperature in °C, not correlated to MCU load.

Return type:

float

ydpg.usbstate()

Returns:

Current state of USB connection. See constants.

Return type:

int

ydpg.usbpowered()

Returns:

true if the Gateway is powered from USB.

Return type:

bool

ydpg.usbvcp()

Returns the virtual COM port parameters set by the PC application. These settings do not affect the actual speed of data exchange through the USB connection, but can be used in the user program to initialize e.g. NMEA 0183 ports to control the speed from the PC.

Parameters are returned in the same order and format as in pyb.UART.init(): baudrate, bits, parity, stop.

Usage example

n0183.deinit()

def usb_clbk(state):
    global uart_rx, uart_tx
    if state == ydpg.USB_COM_PORT:
        params = ydpg.usbvcp()
        uart_rx.init(*params)
        uart_tx.init(*params)

ydpg.usbcallback(usb_clbk)

Returns:

Last parameters of Virtual COM Port.

Return type:

tuple(int, int, int or None, int)

ydpg.usbclear()

Clear the transmit buffer of the USB virtual COM port. This function can be called in the USB state callback to remove the Python Gateway welcome message or obsolete data printed by user code.

ydpg.usbcallback(callback)

Sets callback on USB connection state change.

Parameters:

callback (function(int) or None) – Function to call on state change.

Classes

class ydpg.LED(state=LED.OFF, manual=False)

Initializes the Gateway’s LED and starts the periodic flashing of the normal operating signal sequence (see User Manual). The initialization code is usually included in boot.py. The sequence consists of five flashes, the user can add the sixth flash to the sequence to indicate the state of the program.

#	Color
1	RED if an error is detected on the CAN bus (NMEA 2000), otherwise GREEN.
2	GREEN if data is received from CAN bus, otherwise RED.
3	GREEN when data has been sent to the CAN bus, otherwise RED.
4	GREEN when line feed character (ASCII 10) is received from UART, otherwise RED.
5	GREEN when line feed character has been sent to UART, otherwise RED.
6	User defined, will be absent from the sequence if the user program doesn’t set it’s state.

The manual() method can be used to cancel the periodic flashing and allow the user code to take full control of the LED.

Constants

Name	Value
LED.OFF	0
LED.RED	1
LED.GREEN	2

Methods

deinit()

Turn off the LED and deinitialize the object.

state([state])

Set LED state. In the normal flashing sequence, this method sets the color of the sixth flash in the sequence (see constants). When the manual LED control is used, this method is used to switch the LED off or on and to set it’s color.

Parameters:

state (int) – LED color to set

Returns:

None or current value if state is not provided

Return type:

None or int

once([state])

Overrides the color of the sixths flash in the normal flash sequence for the next flash sequence only. It can be used to signal the occurrence of an event. This method has no effect when manual LED control is used.

Parameters:

state (int or None) – LED color to set

Returns:

None or current value if state is not provided

Return type:

None or int

manual([manual])

Turns on or off manual control of Gateway’s LED.

Parameters:

manual (bool) – manual mode state

Returns:

None or current value if manual is not provided

Return type:

None or bool

off()

In manual LED control mode, the equivalent of LED.state(LED.OFF), otherwise the equivalent of LED.once(LED.OFF).

red()

In manual LED control mode, the equivalent of LED.state(LED.RED), otherwise the equivalent of LED.once(LED.RED).

green()

In manual LED control mode, the equivalent of LED.state(LED.GREEN), otherwise the equivalent of LED.once(LED.GREEN).