Skip to content

void DCC_Decoder::State_Execute() seems to not follow NMRA spec in one case..  #5

Description

@wbertels

While fiddeling around with the DCC monitor and decoder I found the line:

        ///////////////////////////////////////////////////////////
        // Handle as a extd accessory decoder packet  (4 bytes)
    if( ((gPacket[0] & 0xC0) == 0x80)  &&  ((gPacket[1] & 0x85) == 0x01) )

As the NMRA standard
https://www.nmra.org/sites/default/files/s-9.2.1_2012_07.pdf

describes the bytes for the extended accessory decoder as:
{preamble} 0 10AAAAAA 0 0AAA0AA1 0 000XXXXX 0 EEEEEEEE 1

        Comment: check 0x85 is a mask with 10000101, should be 10001001 according to NMRA standard??? 

it seems the 0x85 should be 0x89, as the bits 7, 3 and 0 need to be checked and masked, adding up 0x80 +0x08 +0x01.

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions