PrusaConnect SDK for Printer

Requirements:	basic knowledge of PrusaConnect API docs.

Printer instance

You can create a Printer instance using the constructor and passing server and token to it. These you can find in prusa_printer_settings.ini.

from prusa.connect.printer import Printer, const

SERVER = "https://connect.prusa3d.com"
SN = 'SERIAL_NUMBER_FROM_PRINTER'
FINGERPRINT = 'Printer fingerprint'
TOKEN = 'secret token from prusa_printer_settings.ini'
printer = Printer(const.PrinterType.I3MK3, SN, SERVER, TOKEN)

printer.loop()  # communication loop

Or you can use Printer.from_config() method which reads these values from the ini file.

from prusa.connect.printer import Printer, const

SERVER = "https://connect.prusa3d.com"
SN = 'SERIAL_NUMBER_FROM_PRINTER'
printer = Printer.from_config("./prusa_printer_settings.ini",
                              const.PrinterType.I3MK3, SN)

printer.loop()  # communication loop

If the printer has not been registered yet, you need to use Printer.register() to get a temporary code. This code is then used in the Add Printer form in Connect Web. After the printer has been added to Connect, Printer.get_token() will return printer's persistent token.

from time import sleep
from prusa.connect.printer import Printer, const

SERVER = "https://connect.prusa3d.com"
SN = 'SERIAL_NUMBER_FROM_PRINTER'
printer = Printer(const.PrinterType.I3MK3, SN, SERVER)

tmp_code = printer.register()
print(f"Use this code `{tmp_code}` in add printer form "
      f"{SERVER}/printers/overview?code={tmp_code}.")

token = None
while token is None:
    token = printer.get_token(tmp_code)
    sleep(1)

print("Printer is registered with token %s" % token)

Telemetry

Printer must send telemetry to connect at least each second. Because obtaining telemetry values might not be atomic, this must be done in a different thread than Printer.loop.

from threading import Thread
from time import sleep

...

# start communication loop
thread = Thread(target=printer.loop)
thread.start()

# each second send telemetry to internal queue in the main-thread
while True:
    printer.telemetry(const.State.READY, temp_nozzle=24.1, temp_bed=23.2)
    sleep(1)

Events

Events are a way to send information about the printer to Connect. They can be split into a few groups:

Command answers - Response for Connect if the command was be ACCEPTED, REJECTED, etc. These are handled by the SDK in Printer.loop method or in Command.__call__ method.

State change - indicating that the printer state has changed. This are sent by Printer.set_state method.

FILE INFO events which are created by FileSystem object.

Alternatively you can inform Connect about other events like attaching/detaching of storage. You can do this by calling Printer.event_cb.

Examples for these groups follow below.

Event callback

You can inform Connect about some specific situation using events.

from threading import Thread

...

# start communication loop
thread = Thread(target=printer.loop)
thread.start()

try:
    ...
except Exception as err:
    # send event to internal queue
    printer.event_cb(const.Event.ATTENTION, const.Source.WUI,
                     reason=str(err))

Printer state

from threading import Thread
from time import sleep

...

# start communication loop
thread = Thread(target=printer.loop)
thread.start()

# toggle the state each second
while True:
    if printer.state == const.State.READY:
        printer.set_state(const.State.BUSY, const.Source.MARLIN)
    elif printer.state == const.State.BUSY:
        printer.set_state(const.State.READY, const.Source.MARLIN)
    sleep(1)

Files

Files are sent to Connect in a dictionary using the SEND_INFO command. Within the SEND_INFO commmand response, there's a files dictionary with all files and folders within the Filesystem. Here you can find info about file (or folder). Available info is type, name, ro (read only), m_timestamp (when the file was last modified), size and in case of folder, info about its children. Also you can find here information about free_space and total_space of the each storage, if available.

Commands

When Connect sends a command in the answer to telemetry, Printer.command object will be created. Please note that the Printer.loop only creates and parametrizes this command instance. It never calls this command's handler. It must happen in another (e.g. main) thread.

Each command handler must return a dictionary with at least the source key.

Normally each command is marked as finished by the FINISHED event. You might want to override it by some other event, e.g. INFO. In that case, also the event key must be set in the returned dictionary.

Additional data for this event is passed using the data key with a dictionary as a value.

For further detail see https://connect.prusa3d.com/docs/printer_communication or have a look at the implementation details in the SDK (INFO event handled by the Printer.get_info() method).

from threading import Thread
from time import sleep

...

@printer.handler(const.Command.START_PRINT)
def start_print(args: List[str]):
    """This handler will be called when START_PRINT command was sent to
       the printer."""
    printer.set_state(const.State.PRINTING, const.Source.CONNECT)
    print("Printing file: {args[0]}")
    ...

@printer.handler(const.Command.STOP_PRINT)
def start_print(args: List[str]):
    """This handler will be called when STOP_PRINT command was sent to
       the printer."""
    printer.set_state(const.State.READY, const.Source.CONNECT)
    print("Printing stopped")
    ...

# communication loop
thread = Thread(target=printer.loop)
thread.start()

# try run command handler each 100 ms
while True:
    printer.command()
    sleep(0.1)