Results 1 to 5 of 5

Thread: Panasonic Dynamic IR Codes

  1. #1
    Automated Home Guru JonS's Avatar
    Join Date
    Dec 2007
    Location
    Suffolk
    Posts
    201

    Question Panasonic Dynamic IR Codes

    I've had a little sucess with IR code relay and actuation but ha never been able to control an old Panasonic TV. I've done some more tests and by repeatedly recording the same IR-button to different buttons on the Cortex-IR-handset, exporting the handset to the IR store and then a file, and then comparing the strings. It appears that each time the code for a given function changes.
    Has anyone come across this type of dynamic behaviour before, or better worked out how to get idratek devices and Cortex to cope?
    Thanks
    JonS

  2. #2
    Automated Home Legend Karam's Avatar
    Join Date
    Mar 2005
    Posts
    821

    Default

    I haven't looked at this stuff for a while but it seems odd that it should change codes repeatedly - doesn't seem to make sense unless they are trying to encrypt for some reason. The only code changing I have been aware of is in RC5/6 where one bit is toggled on each press, and on a remote with function select for example where you might select CD player (anyone remember these ? ) as opposed to tuner then the codes for the same buttons eg. numbers might then change.

    Only other thing I can think of is it might look like the code is changing but that this is infact due to tolerances of the pulse measurements. The strings show numbers representing successive pulse durations. Of course these are subject to measurement errors which can be worse if the environment is IR noisy (TV's themselves are sometimes a good source ....). The firmware/software already has tolerance acceptance filtering to deal with this but obviously you can only go so far. So if you did the tests with the TV on or with fluorescents on try doing again without.

  3. #3
    Automated Home Guru JonS's Avatar
    Join Date
    Dec 2007
    Location
    Suffolk
    Posts
    201

    Default

    I hadn't considered noise, so I recorded a single button 6 times with no lights, screens etc on. Checking with notepad++ only 2 of the recordings are the same, none work, showing minor differences between the different recordings e.g. in some character positions I saw 90 in one and A0 in the same position in another record.. On comparing the TV codes with the others I've recorded I noted that they are all significantly longer - 205 characters between the $ whereas the max for the other remotes is only ~170 characters
    When I press the virtual button, the LED on the TV which usually lights when a remote button is pressed doesn't, so the infared word isn't correctly formed let along recognised.
    So maybe I've hit a limit either in length or rate of the burst?
    JonS

  4. #4
    Automated Home Legend Karam's Avatar
    Join Date
    Mar 2005
    Posts
    821

    Default

    Might be worth sending these to us, or perhaps better to do a node profile on the module which learnt the codes - at least up to the end of the IR RX frame stores - and send this.

  5. #5
    Automated Home Guru JonS's Avatar
    Join Date
    Dec 2007
    Location
    Suffolk
    Posts
    201

    Default

    To close the thread I sent the codes through and yes they do overrun the store size. Karam offered a fix (increase store size, reduce number of stores) but I've not followed up as its not a big issue for me.
    JonS

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •