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You are here: OpenWrt Wiki » Documentation » HOWTOs » LIRC audio_alsa

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— doc:howto:lirc-audio_alsa [2012/11/08 18:15] (current)
danitool created: LIRC audio_alsa howto
Line 1: Line 1:
 +====== LIRC audio_alsa ======
 +[[http://www.lirc.org/|LIRC]] is a package that allows you to decode and send infra-red signals of many (but not all) commonly used remote controls.
 +Be aware you'll need a **sound card** with microphone input. A cheap usb sound card can do the job.
 +
 +The audio_alsa module lets you to use a soundcard input to receive infrarred signals. The basic idea is that the output of the IR module (somewhere in the range from 0 to ~3-4V) can be limited by using the attenuator built into every audio-card (also known as "mixer sliders").
 +
 +===== Prepare your hardware =====
 +This is a schematic for connecting the IR module to our soundcard input \\
 +{{:inbox:howto:lirc-audio_alsa.jpg?500|}} \\
 +A TSOP1736 IR module also works. The +5V should be as stable as possible to avoid power supply disturbances.
 +
 +===== Prepare your your software =====
 +To use the audio_alsa module you'll need to build Openwrt with the package lirc and alsamixer. Install both before building your own firmware.
 +<code>./scripts/feeds update -a
 +./scripts/feeds install lirc alsa-utils
 +</code>
 +| {{:meta:icons:tango:package-x-generic.png|}} | The lirc package is not built as default with //audio_alsa//, and it seems partially broken. As a result of this you must modify the Makefile for lirc. Or just download this fixed one: \\ [[https://files.myopera.com/danitool/livebox/wifiradio/lirc-audio_alsa-AA.zip|lirc-audio_alsa-AA.zip]] \\ Prepared to work with OpenWrt Attitude Adjustment, but it may also work with Backfire. Replace the lirc directory under feeds with this new one. |
 +
 +As usually build your custom firmware but select alsa-utils, lirc:
 +<code>
 +Location:
 +    -> Utilities
 +</code>
 +<code>
 +┌─────────────────────────────────── Utilities ───────────────────────────────────┐
 +│ ┌─────────────────────────────────────────────────────────────────────────────┐ │ 
 +│ │    Boot Loaders  --->                                                      │ │ 
 +│ │    Editors  --->                                                          │ │ 
 +│ │    Filesystem  --->                                                        │ │ 
 +│ │    Terminal  --->                                                          │ │ 
 +│ │    disc  --->                                                              │ │ 
 +│ │ <*> alsa-utils............ ALSA (Advanced Linux Sound Architecture) utilitie│ │ 
 +│ │ < > alsa-utils-seq.................................. ALSA sequencer utilitie│ │ 
 +│ │ < > alsa-utils-tests.......... ALSA utilities test data (adds ~1.3M to image│ │ 
 +│ │ < > bzip2.................................... bzip2 is a compression utility│ │ 
 +│ │ < > cal................................................... display a calenda│ │ 
 +│ │ < > comgt............................... Option/Vodafone 3G/GPRS control too│ │ 
 +│ │ < > dmesg............................ print or control the kernel ring buffe│ │ 
 +│ │ < > dropbearconvert.......................... Utility for converting SSH key│ │ 
 +│ │ < > fconfig..................................... RedBoot configuration edito│ │ 
 +│ │ < > flock.................................... manage locks from shell script│ │ 
 +│ │ < > gdb......................................................... GNU Debugge│ │ 
 +│ │ < > gdbserver................................. Remote server for GNU Debugge│ │ 
 +│ │ < > getopt.................................. parse command options (enhanced│ │ 
 +│ │ < > gpioctl................................... Tool for controlling gpio pin│ │ 
 +│ │ < > hwclock.................................. query or set the hardware cloc│ │ 
 +│ │ < > iconv................................... Character set conversion utilit│ │ 
 +│ │ < > iwcap.................................... Simple radiotap capture utilit│ │ 
 +│ │ < > iwinfo.......................... Generalized Wireless Information utilit│ │ 
 +│ │ --- jshn................................................. JSON SHell Notatio│ │ 
 +│ │ < > kexec-tools.......................................... Kernel boots kerne│ │ 
 +│ │ < > ldconfig............................... Shared library path configuratio│ │ 
 +│ │ < > ldd.................................................... LDD trace utilit│ │ 
 +│ │ <*> lirc................................ LIRC - Linux Infrared Remote Contro│ │ 
 +│ │ < > logger......... a shell command interface to the syslog system log modul│ │ 
 +│ │ < > look......................... display lines beginning with a given strin│ │ 
 +│ └─v(+)────────────────────────────────────────────────────────────────────────┘ │ 
 +├─────────────────────────────────────────────────────────────────────────────────┤ 
 +│                        <Select>    < Exit >    < Help >                        │ 
 +└─────────────────────────────────────────────────────────────────────────────────┘
 +</code>
 + and lirc utitilities:
 +<code>
 +Location:
 +    -> Utilities
 +      -> lirc
 +</code>
 +<code>
 +┌─────────── lirc............. LIRC - Linux Infrared Remote Control ────────────┐
 +│ ┌───────────────────────────────────────────────────────────────────────────┐ │
 +│ │ --- lirc.................. LIRC - Linux Infrared Remote Control          │ │
 +│ │ <*>  lircdaemonadd...................... Daemon Additional Files        │ │
 +│ │ <*>  lirctools....................................... LIRC tools        │ │
 +│ │                                                                          │ │
 +│ └───────────────────────────────────────────────────────────────────────────┘ │
 +├───────────────────────────────────────────────────────────────────────────────┤
 +│                  <Select>    < Exit >    < Help >                            │
 +└───────────────────────────────────────────────────────────────────────────────┘
 +</code>
 +
 +Build openwrt, and flash your custom firmware. Now you have lirc prepared to work.
 +
 +| {{:meta:icons:tango:dialog-information.png|}} | Note the file **/etc/lircd.conf** is specific for your remote. You'll may need to use [[http://www.lirc.org/html/irrecord.html|irrecord]] to get one for your own remote if you don't find any in the [[http://lirc.sourceforge.net/remotes/|lirc database]]. |
 +
 +===== Make it work =====
 +Execute the lirc daemon
 +<code>
 +mkdir /var/run/lirc
 +lircd --driver=audio_alsa -d plughw@24000
 +</code>
 +
 +Now execute irw, to test your remote, the codes are shown when you press any button.
 +<code>root@OpenWrt:/# irw
 +00000000000005e9 00 + rct3004
 +00000000000005ea 00 - rct3004
 +00000000000005ea 01 - rct3004
 +00000000000005dd 00 power rct3004
 +00000000000005d0 00 3 rct3004
 +00000000000005d0 01 3 rct3004
 +00000000000005c9 00 5 rct3004
 +00000000000005c9 01 5 rct3004
 +00000000000005c1 00 4 rct3004
 +00000000000005c1 01 4 rct3004</code>
 +If nothing is shown you may need to calibrate the infrared receiver with alsamixer:
 +<HTML><table><tr><td><code>
 +┌───────── AlsaMixer v1.0.24.2 ─────────┐
 +│ Card: Generic USB Audio Device        │
 +│ Chip: USB Mixer                      │
 +│ View: Playback                        │
 +│ Item: Speaker [dB gain: -0.06, -0.06] │
 +│    ┌──┐        ┌──┐                  │
 +│    │▒▒│        │  │                  │
 +│    │▒▒│        │  │                  │
 +│    │▒▒│        │  │                  │
 +│    │▒▒│        │  │                  │
 +│    │▒▒│        │  │                  │
 +│    │▒▒│        │▒▒│                  │
 +│    │▒▒│        │▒▒│                  │
 +│    │▒▒│        │▒▒│                  │
 +│    │▒▒│        │▒▒│                  │
 +│    │▒▒│        │▒▒│                  │
 +│    ├──┤        ├──┤        ┌──┐      │
 +│    │OO│        │MM│        │OO│      │
 +│    └──┘        └──┘        └──┘      │
 +│  100<>100      52                  │
 +│ <  Speaker  >    Mic    Auto Gain C  │
 +└───────────────────────────────────────┘
 +</code></td></tr></table></HTML>
 +Sometimes is better to use Auto Gain other times not (**m** key to disable/enable). So play with it together with the next control: \\
 +**Press F4** to enter the Capture control.
 +<HTML><table><tr><td><code>
 +┌───────── AlsaMixer v1.0.24.2 ─────────┐
 +│ Card: Generic USB Audio Device        │
 +│ Chip: USB Mixer                      │
 +│ View: Capture                        │
 +│ Item: Mic [dB gain: 14.88]            │
 +│                                      │
 +│                ┌──┐                  │
 +│                │  │                  │
 +│                │  │                  │
 +│                │  │                  │
 +│                │  │                  │
 +│                │▒▒│                  │
 +│                │▒▒│                  │
 +│                │▒▒│                  │
 +│                │▒▒│                  │
 +│                │▒▒│                  │
 +│                │▒▒│                  │
 +│                L└──┘R                │
 +│              CAPTURE                │
 +│                  62                  │
 +│              <  Mic  >              │
 +└───────────────────────────────────────┘
 +</code></td></tr></table></HTML>
 +Now play with the gain (arrow up/down) until your remote shows its codes with irw. Once calibrated press Esc key to exit alsamixer.
 +
 +==== irexec ====
 +Ok nothing new here, just configure [[http://www.lirc.org/html/configure.html#lircrc_format|lircrc]] as described in the LIRC website. The file /etc/wifiradio/lircrc is an example. Run the [[http://www.lirc.org/html/irexec.html|irexec]] daemon with a command like this:
 +<code>irexec --daemon /etc/wifiradio/lircrc</code>
 +Now everytime you press a button in your remote, irexec will execute the associated commands in the lircrc file.
 +
 +You can put the commands to calibrate alsamixer and execute commands in /etc/rc.local, to autostart lircd and irexec once you got it working.
 +<code>mkdir /var/run/lirc
 +amixer -q set Mic capture 62%
 +lircd --driver=audio_alsa -d plughw@24000
 +irexec --daemon /etc/wifiradio/lircrc
 +</code>
 +
 +===== Notes =====
 +Successfully tested with a [[toh:inventel:DV4210|Livebox 1]] router under Backfire, using a CSOUNDU Conceptronic usb audio card, and TSOP1736  --- //danitool 2012/11/04 15:02//
 +
 +===== Tags =====
 +{{tag>wip lirc}}

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doc/howto/lirc-audio_alsa.txt · Last modified: 2012/11/08 18:15 by danitool