stjordanis / ocpp

Python implementation of the Open Charge Point Protocol (OCPP).

OCPP

Python package implementing the JSON version of the Open Charge Point Protocol (OCPP). Currently OCPP 1.6 (errata v4), OCPP 2.0 and OCPP 2.0.1 (Final Version) are supported.

You can find the documentation on rtd.

Installation

You can either the project install from Pypi:

$ pip install ocpp

Or clone the project and install it manually using:

$ pip install .

Quick start

Below you can find examples on how to create a simple OCPP 2.0 central system as well as an OCPP 2.0 charge point.

Note

To run these examples the dependency websockets is required! Install it by running:

$ pip install websockets

Central system

The code snippet below creates a simple OCPP 2.0 central system which is able to handle BootNotification calls. You can find a detailed explanation of the code in the Central System documentation_.

import asyncio
import logging
import websockets
from datetime import datetime

from ocpp.routing import on
from ocpp.v201 import ChargePoint as cp
from ocpp.v201 import call_result

logging.basicConfig(level=logging.INFO)


class ChargePoint(cp):
    @on('BootNotification')
    async def on_boot_notification(self, charging_station, reason, **kwargs):
        return call_result.BootNotificationPayload(
            current_time=datetime.utcnow().isoformat(),
            interval=10,
            status='Accepted'
        )


async def on_connect(websocket, path):
    """ For every new charge point that connects, create a ChargePoint
    instance and start listening for messages.
    """
    try:
        requested_protocols = websocket.request_headers[
            'Sec-WebSocket-Protocol']
    except KeyError:
        logging.info("Client hasn't requested any Subprotocol. "
                 "Closing Connection")
    if websocket.subprotocol:
        logging.info("Protocols Matched: %s", websocket.subprotocol)
    else:
        # In the websockets lib if no subprotocols are supported by the
        # client and the server, it proceeds without a subprotocol,
        # so we have to manually close the connection.
        logging.warning('Protocols Mismatched | Expected Subprotocols: %s,'
                        ' but client supports  %s | Closing connection',
                        websocket.available_subprotocols,
                        requested_protocols)
        return await websocket.close()

    charge_point_id = path.strip('/')
    cp = ChargePoint(charge_point_id, websocket)

    await cp.start()


async def main():
    server = await websockets.serve(
        on_connect,
        '0.0.0.0',
        9000,
        subprotocols=['ocpp2.0.1']
    )
    logging.info("WebSocket Server Started")
    await server.wait_closed()

if __name__ == '__main__':
    asyncio.run(main())

Charge point

import asyncio
import logging
import websockets

from ocpp.v201 import call
from ocpp.v201 import ChargePoint as cp

logging.basicConfig(level=logging.INFO)


class ChargePoint(cp):

   async def send_boot_notification(self):
       request = call.BootNotificationPayload(
               charging_station={
                   'model': 'Wallbox XYZ',
                   'vendor_name': 'anewone'
               },
               reason="PowerUp"
       )
       response = await self.call(request)

       if response.status == 'Accepted':
           print("Connected to central system.")


async def main():
   async with websockets.connect(
       'ws://localhost:9000/CP_1',
        subprotocols=['ocpp2.0.1']
   ) as ws:

       cp = ChargePoint('CP_1', ws)

       await asyncio.gather(cp.start(), cp.send_boot_notification())


if __name__ == '__main__':
   asyncio.run(main())

Debugging

Python's default log level is logging.WARNING. As result most of the logs generated by this package are discarded. To see the log output of this package lower the log level to logging.DEBUG.

import logging
logging.basicConfig(level=logging.DEBUG)

However, this approach defines the log level for the complete logging system. In other words: the log level of all dependencies is set to logging.DEBUG.

To lower the logs for this package only use the following code:

import logging
logging.getLogger('ocpp').setLevel(level=logging.DEBUG)
logging.getLogger('ocpp').addHandler(logging.StreamHandler())

License

Except from the documents in docs/v16 and docs/v201 everything is licensed under MIT. © The Mobility House

The documents in docs/v16 and docs/v201 are licensed under Creative Commons Attribution-NoDerivatives 4.0 International Public License.