(SOLVED) GPIO (TSOP4838) IR receiver - LIRC inst.?

den_hr

Hi everyone,
My first post here: I've checked previous topics on IR receivers, but the existing ones mostly refer to USB IR receivers.

My issue is that I would like to use a 3-pin IR receiver (TSOP package), like this one:
https://learn.adafruit.com/using-an-ir-remote-with-a-raspberry-pi-media-center/overview

Additional complication is that I'll be using it with a WOlfson audio card (and an I2C LCD)

Now, the idea is to use the Tx and Rx pins exposed on Wolfson audio card (see attachment): actually, just the Rx pin (GPIO15, if I'm not mistaken).

My problem is that I'm not familiar with Arch Linux, and it's like a completely foreign language to me

Naturally, none of the existing instructions for IR/LIRC setup apply to Arch and its systemd...

I've tried unsuccessfuly to find detailed instructions for making this (LIRC) work on Arch, but no dice: the existing "instructions" are quite perfunctory and presume a good working knowledge of Arch and systemd

The previously mentioned link here:
http://www.arch-ed.dk/systemd-lircd-mceusb-xbmc-and-arch-linux/
actually deals with migrating previous working LIRC setup to new systemd... And my problem is that I want to set it up from scratch - on RuneAudio.
I got as far as installing lirc (after having to upgrade the whole system - scary....) and disabling serial console (I'll need that Rx pin used by the ttyAMA0)...

I've also tried to set up the necessary files (/etc/systemd/system/lirc.service, /etc/conf.d/lircd.conf), and lirc DOES seem to start...
Now I need to set up remote commands using irrecord, but I can't seem to get it started: it says the dev/lirc0 is taken by lircd, and if I stop lircd using:

systemctl stop lirc.service

my /dev/lirc0 doesn't exist any more...

In short:
1) is there a detailed description of getting LIRC installed and set up from scratch under Arch (i.e. applicable to RuneAudio)?
2) how do I reassign GPIO15 to be used by LIRC under Arch/RuneAudio?

Thanks in advance,
Denis

Attachments

: wolfson_audio_card_wiring_RuneAud.jpg (40.31 KiB) Viewed 5920 times

den_hr

BTW, today I managed to set up LIRC and the same TSOP IR sensor and a remote control I have at hand fairly quickly in Volumio (although not without hiccups!) - took me some revisiting of web resources regarding Lirc...
What matters is that now I'm sure that the IR receiver (sensor) works, and that the wiring is OK

(Last year I managed to burn one IR sensor by wiring it to RasPi incorrectly - luckily I damaged only the IR sensor, and not the RasPi!)

I'd much prefer to use RuneAudio: the UI is much quicker, the OS boots very fast, and I generally prefer it to Volumio.... But, I'm at a total loss in Arch Linux architecture and config files.

So, if anyone can shed any light on how to go about setting up IR sensor using Lirc in RuneAudio, I'd appreciate it very much...

den_hr

As usual, I'm replying to myself

Anyway, I managed to get it working without too much hassle - looks like I overcomplicated things by following outdated instructions.

Once I deleted all the files I made, and started afresh, everyting fell into place pretty much by itself...

I was able to do "modprobe lirc_rpi", lirc_rpi was loaded, and irrecord was reacting and recording commands and keypresses.

The only thing I left was addition of following to the file "/etc/modules-load.d/raspberrypi.conf":

lirc_dev
lirc_rpi

command:

cat /sys/kernel/debug/gpio

returns the following:

[root@runeaudio lcd]# cat /sys/kernel/debug/gpio
GPIOs 0-53, bcm2708_gpio:
 gpio-14  (lirc_rpi ir/out     ) in  lo
 gpio-15  (lirc_rpi ir/in      ) in  hi
 gpio-16  (led0                ) out hi
 gpio-17  (arizona /RESET      ) out hi
 gpio-22  (LDO1                ) out hi

I also have /etc/conf.d/lircd.conf:

LIRCD_ARGS="--uinput"
DRIVER="default"
DEVICE="/dev/lirc0"
MODULES="lirc_rpi"

and /etc/modprobe.d/lirc.conf:

options lirc_rpi gpio_in_pin=15 gpio_out_pin=14

Basically, I can take it from there without any further ado.

BTW, there is no need to write any custom "lirc.service" or anything - it already exists on the system, and is invoked simply by entering:

 systemctl start lircd.service

- the file is already located at
/usr/lib/systemd/system/lircd.service
- or just do:

systemctl enable lircd.service

to permanently enable it...

the file "irexec.service", which will be needed later, is located at:
/usr/share/lirc/contrib/irexec.service
- and I'll later copy it to /usr/lib/systemd/system/irexec.service and enable it, just like the lircd.service...

- with perhaps introducing a brief pause, as described here: #47814

ACX

Thank you den_hr for the detailed instructions, I'm sure that this topic will be useful for somebody in the future. Sharing your progress is a good way to contribute to this project!