SET_CAN_BUS_FILTER
Python Code
from flojoy import flojoy, DeviceConnectionManager, DataContainer
from typing import Optional
import can
@flojoy(deps={"python-can": "4.3.1"})
def SET_CAN_BUS_FILTER(
CAN_address: str,
can_id: int = 0x0000001,
can_mask: int = 0xFFFFFFFF,
extended: bool = False,
default: Optional[DataContainer] = None,
) -> Optional[DataContainer]:
"""Attach a message filter to a CAN bus connection.
Setup a message filtering can be set up for each bus.
The binary operation is as follow: <received_can_id> & can_mask == can_id & can_mask
All messages that match at least one filter are returned.
Where the interface supports it, this is carried out in the hardware or kernel layer - not in Python.
A connection to the device is required. Use a CAN_CONNECT block to connect to a CAN device.
Parameters
----------
CAN_address : str
The CAN bus address to attach the filter to.
can_id : int
The ID of the message to filter.
can_mask : int
Apply a binary mask to the ID and can_id.
extended : bool
If true, only matches messages where <received_is_extended> == extended.
Returns
-------
DataContainer
Optional: None
"""
connection: can.interface.Bus = DeviceConnectionManager.get_connection(
CAN_address
).get_handle()
connection.set_filters(
[{"can_id": can_id, "can_mask": can_mask, "extended": extended}]
)
return None
Example
This application demonstrates how to use multiple CAN blocks to connect to a PEAK-USB device and read messages from it. The PEAK-USB device is a USB-to-CAN interface that enables you to connect a computer to a CAN network. This device is used in this case to capture the messages of a particular sensor by filtering them directly at the kernel level, thus reducing the load on the CPU, and save those messages to a log file locally.
Once the app is done, the generated logs are exported to an S3 bucket to keep a record of the sensor’s data for further analysis.
To replicate this application, you must connect the PEAK-USB to your computer and install the required driver (refer to the PEAK_CONNECT blocks for more information on the necessary driver for your platform). Then, simply specify the PEAK-USB channel in the required blocks, and this Flojoy application will log the messages received by the device!
Detecting channels
A valuable block is the PEAK_DETECT_AVAILABLE_DEVICE. This block allows you to display the devices using the PCAN interface that are connected to your computer.