LIRC Setup for GPIO based IR RX on Ubuntu 18.04

Please follow these 4 steps.

Install LIRC Package
Modify hardware.conf
Register lircd.conf
Restart lircd service

$ sudo apt-get install lirc

First, you need to set up lirc_options.conf under /etc/lirc/.
This includes driver, port and other infortant configuration and is generated by default when lirc is installed.

target

$ sudo vi /etc/lirc/lirc_options.conf

The following parts are needed to modified.

(1) driver and device

driver          = default
device          = /dev/lirc0

(2) module init

Let's suppose to connect IR output of your extra IR receiver module to Pin '11' of expansion connectors (J2) of ODROID-C2.
(Expandsion net name : GPIOX.BIT19, GPIO number : 247)

[modinit]
code = /sbin/modprobe gpio-ir-recv
# gpio_nr must be adjusted based on port connections
code1 = /sbin/modprobe gpioplug-ir-recv gpio_nr=247 active_low=1

(3) input event

[lircd-uinput]
add-release-events = True
release-timeout    = 50
release-suffix     = _EVUP

Please note that some parts in lirc_options.conf depend on the toolchain version,
so select the correct conf file among the following references based on your board.

Reference lirc_options.conf

ODROID-C4

For the example on ODROID-C4, Pin#11 (GPIOX.3, GPIO479) is considered.

lirc_options.conf

[lircd]
nodaemon        = False
driver          = default
device          = /dev/lirc0
output          = /var/run/lirc/lircd
pidfile         = /var/run/lirc/lircd.pid
plugindir       = /usr/lib/aarch64-linux-gnu/lirc/plugins
permission      = 666
allow-simulate  = No
repeat-max      = 600
#effective-user =
#listen         = [address:]port
#connect        = host[:port]
#loglevel       = 6
#release        = true
#release_suffix = _EVUP
#logfile        = ...
#driver-options = ...
 
[lircmd]
uinput          = False
nodaemon        = False
 
[modinit]
code = /sbin/modprobe gpio-ir-recv
# gpio_nr must be adjusted based on port connections.
code1 = /sbin/modprobe gpioplug-ir-recv gpio_nr=479 active_low=1
 
[lircd-uinput]
add-release-events = True
release-timeout    = 50
release-suffix     = _EVUP

ODROID-N2

For the example on ODROID-N2, Pin#11 (GPIOX.3, GPIO479) is considered.

lirc_options.conf

[lircd]
nodaemon        = False
driver          = default
device          = /dev/lirc0
output          = /var/run/lirc/lircd
pidfile         = /var/run/lirc/lircd.pid
plugindir       = /usr/lib/aarch64-linux-gnu/lirc/plugins
permission      = 666
allow-simulate  = No
repeat-max      = 600
#effective-user =
#listen         = [address:]port
#connect        = host[:port]
#loglevel       = 6
#release        = true
#release_suffix = _EVUP
#logfile        = ...
#driver-options = ...
 
[lircmd]
uinput          = False
nodaemon        = False
 
[modinit]
code = /sbin/modprobe gpio-ir-recv
# gpio_nr must be adjusted based on port connections.
code1 = /sbin/modprobe gpioplug-ir-recv gpio_nr=479 active_low=1
 
[lircd-uinput]
add-release-events = True
release-timeout    = 50
release-suffix     = _EVUP

ODROID-C2

For the example on ODROID-C2, Pin#11 (GPIOX.BIT19, GPIO247) is considered.

lirc_options.conf

[lircd]
nodaemon        = False
driver          = default
device          = /dev/lirc0
output          = /var/run/lirc/lircd
pidfile         = /var/run/lirc/lircd.pid
plugindir       = /usr/lib/aarch64-linux-gnu/lirc/plugins
permission      = 666
allow-simulate  = No
repeat-max      = 600
#effective-user =
#listen         = [address:]port
#connect        = host[:port]
#loglevel       = 6
#release        = true
#release_suffix = _EVUP
#logfile        = ...
#driver-options = ...
 
[lircmd]
uinput          = False
nodaemon        = False
 
[modinit]
code = /sbin/modprobe gpio-ir-recv
# gpio_nr must be adjusted based on port connections.
code1 = /sbin/modprobe gpioplug-ir-recv gpio_nr=247 active_low=1
 
[lircd-uinput]
add-release-events = True
release-timeout    = 50
release-suffix     = _EVUP

ODROID-XU4

For the example on ODROID-XU4, Pin#13 (GPX1.5, GPIO21) is considered.

lirc_options.conf

[lircd]
nodaemon        = False
driver          = default
device          = /dev/lirc0
output          = /var/run/lirc/lircd
pidfile         = /var/run/lirc/lircd.pid
plugindir       = /usr/lib/arm-linux-gnueabihf/lirc/plugins
permission      = 666
allow-simulate  = No
repeat-max      = 600
#effective-user =
#listen         = [address:]port
#connect        = host[:port]
#loglevel       = 6
#release        = true
#release_suffix = _EVUP
#logfile        = ...
#driver-options = ...
 
[lircmd]
uinput          = False
nodaemon        = False
 
[modinit]
code = /sbin/modprobe gpio-ir-recv
# gpio_nr must be adjusted based on port connections.
code1 = /sbin/modprobe gpioplug-ir-recv gpio_nr=21 active_low=1
 
[lircd-uinput]
add-release-events = True
release-timeout    = 50
release-suffix     = _EVUP

ODROID-C1

For the example on ODROID-C1, Pin#7 (GPIOY.3, GPIO83) is considered.

lirc_options.conf

[lircd]
nodaemon        = False
driver          = default
device          = /dev/lirc0
output          = /var/run/lirc/lircd
pidfile         = /var/run/lirc/lircd.pid
plugindir       = /usr/lib/arm-linux-gnueabihf/lirc/plugins
permission      = 666
allow-simulate  = No
repeat-max      = 600
#effective-user =
#listen         = [address:]port
#connect        = host[:port]
#loglevel       = 6
#release        = true
#release_suffix = _EVUP
#logfile        = ...
#driver-options = ...
 
[lircmd]
uinput          = False
nodaemon        = False
 
[modinit]
code = /sbin/modprobe gpio-ir-recv
# gpio_nr must be adjusted based on port connections.
code1 = /sbin/modprobe gpioplug-ir-recv gpio_nr=83 active_low=1
 
[lircd-uinput]
add-release-events = True
release-timeout    = 50
release-suffix     = _EVUP

lircd.conf files under /etc/lirc/lircd.conf.d/ include signal timing information and provide mappings from button presses to key symbols.
You need to add a new lircd.conf based on your custom remote controller.

target

$ sudo vi /etc/lirc/lircd.conf.d/hk.lircd.conf

reference lircd.conf

This reference hk.lircd.conf is to support Hardkernel IR remote controller.
https://www.hardkernel.com/shop/ir-remote-controller/

hk.lircd.conf

begin remote
 
name odroid
bits 16
flags SPACE_ENC|CONST_LENGTH
eps  30
aeps 100
 
header 9000 4500
one 563 1688
zero 563 564
ptrail 563
pre_data_bits 16
pre_data 0x4DB2
repeat 9000 2250
gap 100000
toggle_bit_mask 0x0
    begin codes
        KEY_LEFT  0x9966
        KEY_RIGHT  0x837C
        KEY_UP  0x53AC
        KEY_DOWN  0x4BB4
        KEY_ENTER  0x738C
        KEY_HOME  0x41BE
        KEY_MUTE  0x11EE
        KEY_MENU  0xA35C
        KEY_BACK  0x59A6
        KEY_VOLUMEDOWN  0x817E
        KEY_VOLUMEUP  0x01FE
        KEY_POWER  0x3BC4
    end codes
end remote

target

$ sudo service lircd restart
$ sudo service lircd-uinput restart

To confirm if the LIRC daemon is running based on gpio-ir-recv, check device nodes and protocol name of ir-keytable.

target

$ ls /dev/lirc*
/dev/lirc0

If you have the warning No such device during modprobe gpioplug-ir-recv,
check if the gpio_nr is already assigned to another purpose and change to another pins.

https://wiki.odroid.com/odroid-c2/application_note/lirc/lirc_ubuntu18.04#how_to_test