MF4_CREATE_READER
Python Code
from flojoy import flojoy, File, Stateful, DataContainer
import can
from typing import Optional
@flojoy(deps={"python-can": "4.3.1", "asammdf": "7.4.1"})
def MF4_CREATE_READER(
file: File,
default: Optional[DataContainer] = None,
) -> Stateful:
"""Create a file reader for the MF4 format.
Read CAN data from an ASAM Measurement Data File v4 (.mf4) as specified by the ASAM MDF standard (see https://www.asam.net/standards/detail/mdf/).
Parameters
----------
file : File
The file to write from.
Returns
-------
Stateful
A stateful object that contains can a list of message.
"""
reader = can.io.MF4Reader(file.unwrap())
messages = []
for message in reader:
messages.append(message)
return Stateful(messages)
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.