Topics

  • How it all works together
  • Build the lirc serial interface
  • Build the lirc serial driver
  • Compile & install the daemon
  • Hey! This thing won't work!
  • How does lirc_keybd do things?

    • What you do when it won't

    Ok, so it doesn't work... Don't send me email unless you are willing to pay my hourly rate (I do accept PayPal ;-), otherwise you will be ignored! Just how do you find out what is wrong to find what it is that needs fixing? This is where some basic skills at problem solving are needed. First we have to know how it is supposed to work, then we need to verify that each part is working (or not). The chain of events is as follows:

    IR_diode->lirc_serial->lirc_dev->lircd->lirc_keybd->uinput

    If anything breaks in that chain, it won't work.
    Your problem is probably that nothing is being "heard" by the lirc_serial driver, assuming of course you did read someplace here that no other lirc driver is to be loaded along with the lirc_serial driver?

    TopTesting the lirc_serial driver

    Check that, get to text console, type in 'lsmod | grep lirc'. You should only see something like this:

    lirc_serial 12736 0
    lirc_dev 13324 1 lirc_serial

    This shows that the kernel modules are loaded. Next see if you have a /dev/lirc0 with "ls /dev/lirc0". This should be there, if not, you had either not done the "setserial /dev/ttyS? uart none" (replace '?' with serial port number) or the 8250 module was loaded. In either case, you will get some error being reported when you attempted to modprobe lirc_serial, check your system logs (/var/log/message & /var/log/kernel/{info,warnings,errors}).

    Next check to make sure that batteries are, in fact, in the keyboard. Sounds stupid, but I've done it myself. :-P A real simple test to see if the lirc_serial is working is to run mode2 (mode2 -d /dev/lirc0) and plug / unplug the IR phone plug repeatedly. You will see activity being reported from mode2, if not, you need to look carefully at your electronics, or throw that one away and build another?

    Seeing output from mode2 when pressing keys tells us a lot! We now know:

    1. electronics interface is working.
    2. lirc_serial has been properly built.
    3. we have selected the correct /dev/lircX device.


    TopTesting the lircd daemon

    Let us now try to see if lircd is working properly. Load lircd (maybe first kill the first instance of the daemon with "killall lircd") with "lircd -d /dev/lirc0". Interesting that lircd insists upon using /dev/lirc instead of /dev/lirc0, even if /dev/lirc doesn't exist, it won't look for /dev/lirc0. This is likely your problem, lircd will load if you give it the wrong device name to use, it will sit in the process stack (ps ax | grep lircd), but when you try to run irw, lircd will suddenly bail out and terminate. This can be frustrating if you don't know this behavior (what is more frustrating is attempting to read the docs on the lirc.sourceforge.net site! grrr!).

    Before running lircd, ensure that the proper decoder file is in place. Check the contents of /etc/lircd.conf. This must have the contents of the lircd-webpal.conf file in there as one of the remotes listed. Yes, you can list more than one remote control in /etc/lircd.conf, dig very very deeply into the lircd docs and it may tell you this (ok, enough of bashing the lirc docs).

    Run irw now, press some keys on the WebPal keyboard, you should see something like this:

    0000000000000059 00 KBD_ENTER WebPal_Keyboard
    0000000000000059 00 KBD_ENTER WebPal_Keyboard
    000000000000005a 00 BRK_ENTER WebPal_Keyboard
    00000000000000ad 00 ALL_UP WebPal_Keyboard
    0000000000000059 00 KBD_ENTER WebPal_Keyboard
    000000000000005a 00 BRK_ENTER WebPal_Keyboard
    00000000000000ad 00 ALL_UP WebPal_Keyboard
    0000000000000073 00 KBD_SPACE WebPal_Keyboard
    0000000000000073 00 KBD_SPACE WebPal_Keyboard
    0000000000000074 00 BRK_SPACE WebPal_Keyboard
    00000000000000ad 00 ALL_UP WebPal_Keyboard


    TopTom, your lirc_keybd is broken!

    Ok, so far so good. Really we should have fixed things by now! But, ok, so my code is broken... I did add a debug feature to the code to try to see what is going on. Let's goto the source, assuming that you haven't changed anything before you compiled it, edit lirc_keybd.c and where it says "#define DEBUG 0", change that to "#define DEBUG 1", save the file and re-run 'make'. This will build code that will run as an application, not as a daemon, and print out lots of annoying lines of debugging information. Pressing on the ENTER key will print this:

    0000000000000059 00 KBD_ENTER WebPal_Keyboard
    keycode: 59
    0000000000000059 00 KBD_ENTER WebPal_Keyboard
    000000000000005a 00 BRK_ENTER WebPal_Keyboard
    00000000000000ad 00 ALL_UP WebPal_Keyboard
    FuncAllKeysUp (void)
    0000000000000059 00 KBD_ENTER WebPal_Keyboard
    keycode: 59
    000000000000005a 00 BRK_ENTER WebPal_Keyboard
    00000000000000ad 00 ALL_UP WebPal_Keyboard
    FuncAllKeysUp (void)

    Your most likely problem is that you had edited the /etc/lircd.conf file and changed the name of the remote control from "WebPal_Keyboard" to something else. You cannot do this without changing the definition within lirc_keybd.c. The lirc_keybd looks for, and only processes, the remote control it was told to recognize. This is a bit of a safety feature to avoid confusion when multiple remote controls are defined. Another thing, not a feature, but part of how lirc_keybd works is that it looks for the "KBD_xxxx", "BRK_xxxx", and "ALL_UP" strings. These are keywords that tell lirc_keybd what is happening on the IR keyboard side. Don't change these strings unless you change the lirc_keybd source as well. You can change the text following the "KBD_" & "BRK_" text to whatever you wish, lirc_keybd doesn't look at that portion of those strings. Don't change "ALL_UP".