How to get the Reading DID Response by my custom formula about python-udsoncan

[pylessard]

Hi, you are not so far from it. In your case, you need to define a codec with a decode method not encode and you must specify the codec object in your config, not a function. The payload comes in as a binary string. Something like that should do (untested).

class MyCustomCodec(DidCodec):
    def decode(self, payload):
        return (int(payload[0]) << 8 + int(payload[1])) * 0.01544

    def __len__(self):
        return 2

config['data_identifiers'] = {0x019E: MyCustomCodec}

[CSG2019]

Hello pylessard,
Thank you for your guidance.
It seems that I have to define a Class first, which contains the decode(formula) and the response length, then I can call this through the 'config'.
But I don't understand why it return (int(payload[0]) << 8 + int(payload(1))) * 0.01544, actually, I want to do something for the byte4 and byte5 of the response(0x05 0x62 0x01 0x9E 0x03 0x1F). Do the payload[0] and payload[1] represent byte4 and byte5?
Could you please help to explain again?
I tried to run below codes, but the error is TypeError: 'bytes' object is not callable

class MyCustomCodec(udsoncan.DidCodec):
    def decode(self, payload):
        return (int(payload[0]) << 8 + int(payload(1))) * 0.01544

    def __len__(self):
        return 2

config['data_identifiers'] = {0x019E: MyCustomCodec}

[pylessard]

Hi,
The problem is because of the paranthesis used for byte 1. Use square bracket instead. My apologies, I wrote paranthesis in my answer (I work a lot with Matlab, and that software use paranthesis instead of square brackets). I updated my answer.

As for the byte offset, the library strip off the rest of the response. It only feeds the Did data to the Codec.

Regards

[CSG2019]

Hello pylessard,

Thanks for your help. Now it can work as I hope. :) Really appreciated.
I am new to Python and this library. I also didn't notice the parentheses issue previously.
By the way, I can find the encode method in the example of ReadDataByIdentifier, I want to ask, in which case need to define this method?

[pylessard]

Good,
Encode is when you use WriteDataByIdentifier

[CSG2019]

Understand, thanks :)