====== Support GPIO based IR Blaster ======
<WRAP center round important>
This functionality is available on Ubuntu.
  * ODROID-C2 : Version should be 3.14.79-94 (Nov 21, 2016) or higher.
  * ODROID-C1 : Version should be 3.10.104-175 (Nov 21, 2016) or higher.
  * ODROID-XU3/4 : Version should be 4.9.33-42 (Jun 20, 2017) (available on kernel 3.10 with 3.10.104-126 (Nov 29, 2016))
</WRAP>

===== Building and Testing an IR LED Circuit  =====

This is a schematic example for connecting the IR LED to a GPIO output. \\
{{:en:gpio_ir_blaster.png?600}}


The components are not restricted to the parts and values but they can be different, \\
**so please determine R1 and R2 values by checking the capability of IR LED and transistor specifications\\
based on your environment and component parts.** \\

We use the following components for test.
  * IR LED : KID-05BW85
  * NPN Transistor : PBRN123Y
  * R1 : None, in case of the test environment, R1 is included in the RET
  * R2 : 100Ohm, in case of the test environment, the forward current is 20mA and voltage difference between P1 and P2 is 1.9V. (33Ohm - 54mA / 10Ohm - 155mA, It should be specified considering IR LED spec.)

== Example for ODROID-C2 using 40pins Expansion Connectors == 

For example, Pin #7 (GPIO #249) is used and following instructions will be described with the GPIO value. \\
^ LED side   ^  Connector   ^
|  VCC  | Pin #1 - 3.3V Power  |
|  GND  | Pin #6 - Ground  |
|  GPIO  | Pin #7 - GPIOX.BIT21, GPIO #249   |

http://odroid.com/dokuwiki/doku.php?id=en:c2_hardware#expansion_connectors

== Example for ODROID-C1 using 40pins Expansion Connectors == 

For example, Pin #7 (GPIO #83) is used and following instructions will be described with the GPIO value. \\
^ LED side   ^  Connector   ^
|  VCC  | Pin #1 - 3.3V Power  |
|  GND  | Pin #6 - Ground  |
|  GPIO  | Pin #7 - GPIO #83   |

http://odroid.com/dokuwiki/doku.php?id=en:c1_hardware#expansion_connectors

== Example for ODROID-XU4 using 2x15 pins Expansion Connectors == 

For example, Pin #26 (GPIO #24) is used and following instructions will be described with the GPIO value. \\
^ LED side   ^  Connector   ^
|  VCC  | Pin #29 - 1.8V Power  |
|  GND  | Pin #28 - Ground  |
|  GPIO  | Pin #26 - GPIO #24   |

**In case of XU4, voltage level of VDD_IO and GPIO output is 1.8V.\\
Supposing R2 is 10 Ohm, the actual forward current is around 40mA and voltage difference between P1 and P2 is around 400mV. \\ **

http://odroid.com/dokuwiki/doku.php?id=en:xu4_hardware#expansion_connectors
===== Install LIRC Package  =====
<code>
$ sudo apt-get install lirc
</code>

Install LIRC package. While installing lirc, you will be asked the device type of IR receiver and transmitter.\\
Since we will set up later by manual, you can select **None**.\\


And for further information, please refer to the following wiki page.\\
http://odroid.com/dokuwiki/doku.php?id=en:c2_lirc

===== Configuring the LIRC and the driver module  =====
=== LIRC Configuration ===

lirc_odroid module driver is already included by default but, you need to set up hardware.conf and lircd.conf first and then probe the modules with some parameters. \\

<code>
# sudo vi /etc/lirc/hardware.conf
</code>
Specify the kernel driver module and its node.
<code>
#Chosen IR Transmitter
TRANSMITTER="odroid blaster"
TRANSMITTER_MODULES="lirc_odroid lirc_dev"
TRANSMITTER_DRIVER=""
TRANSMITTER_DEVICE="/dev/lirc0"
TRANSMITTER_SOCKET=""
TRANSMITTER_LIRCD_CONF=""
TRANSMITTER_LIRCD_ARGS=""
</code>

About lircd.conf, you can refer to the following link.\\
http://odroid.com/dokuwiki/doku.php?id=en:c2_lirc\\
And the name in lircd.conf will be used to specify key codes using **irsend**.

<code>
begin remote
    name odroid
    bits   16
    .....
    .....
</code>

=== Install module and Run lirc service ===
All necessary configuration is done, you need to install lirc_odroid module and set some parameters.\\
<code>
# The usage of lirc_odroid module
lirc_odroid  gpio_out_pin=${gpio_number} invert=[0 or 1] softcarrier=[0 or 1]
</code>
Supposing to use Pin#7 of ODROID-C2 (GPIO #249),
<code>
# service lirc stop
# modprobe lirc_dev
# modprobe lirc_odroid gpio_out_pin=249 softcarrier=1 invert=1
(automatically, service lirc will be started)
</code>

=== Send IR code using 'irsend'  ===

If lirc_odroid module has been loaded  and lirc service is running normally, you can get the key list as following.\\
Please make sure the remote name is same with the description in /etc/lirc/lircd.conf.
<code>
#root@odroid64:~# irsend LIST odroid ""
irsend: 0000000000009966 KEY_LEFT
irsend: 000000000000837c KEY_RIGHT
irsend: 00000000000053ac KEY_UP
irsend: 0000000000004bb4 KEY_DOWN
irsend: 000000000000738c KEY_ENTER
irsend: 00000000000041be KEY_HOME
irsend: 00000000000011ee KEY_MUTE
irsend: 000000000000a35c KEY_MENU
irsend: 00000000000059a6 KEY_BACK
irsend: 000000000000817e KEY_VOLUMEDOWN
irsend: 00000000000001fe KEY_VOLUMEUP
irsend: 0000000000003bc4 KEY_POWER
</code>

**irsend** is basic LIRC program to send the key code.
<code>
# irsend SEND_ONCE odroid KEY_ENTER
</code>
http://www.lirc.org/html/irsend.html

===== Reference Configuration Files  =====

== hardware.conf ==
<file text hardware.conf>
# /etc/lirc/hardware.conf
#
#Chosen Remote Control
REMOTE="None"
REMOTE_MODULES=""
REMOTE_DRIVER=""
REMOTE_DEVICE=""
REMOTE_SOCKET=""
REMOTE_LIRCD_CONF=""
REMOTE_LIRCD_ARGS=""

#Chosen IR Transmitter
TRANSMITTER="odroid blaster"
TRANSMITTER_MODULES="lirc_odroid lirc_dev"
TRANSMITTER_DRIVER=""
TRANSMITTER_DEVICE="/dev/lirc0"
TRANSMITTER_SOCKET=""
TRANSMITTER_LIRCD_CONF=""
TRANSMITTER_LIRCD_ARGS=""

#Disable kernel support.
#Typically, lirc will disable in-kernel support for ir devices in order to
#handle them internally.  Set to false to prevent lirc from disabling this
#in-kernel support. 
#DISABLE_KERNEL_SUPPORT="true"

#Enable lircd
START_LIRCD="true"

#Don't start lircmd even if there seems to be a good config file
#START_LIRCMD="false"

#Try to load appropriate kernel modules
LOAD_MODULES="true"

# Default configuration files for your hardware if any
LIRCMD_CONF=""

#Forcing noninteractive reconfiguration
#If lirc is to be reconfigured by an external application
#that doesn't have a debconf frontend available, the noninteractive
#frontend can be invoked and set to parse REMOTE and TRANSMITTER
#It will then populate all other variables without any user input
#If you would like to configure lirc via standard methods, be sure
#to leave this set to "false"
FORCE_NONINTERACTIVE_RECONFIGURATION="false"
START_LIRCMD=""
</file>
== lircd.conf ==
<file test 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
</file>
== To support both of IR Tx and Rx simultaneously ==
<code>
#Chosen Remote Control
REMOTE="None"
REMOTE_MODULES="meson-ir"
REMOTE_DRIVER=""
REMOTE_DEVICE="/dev/lirc0"
REMOTE_SOCKET=""
REMOTE_LIRCD_CONF=""
REMOTE_LIRCD_ARGS="--uinput"

#Chosen IR Transmitter
TRANSMITTER="Home-brew (odroid gpio)"
TRANSMITTER_MODULES="lirc_odroid lirc_dev"
TRANSMITTER_DRIVER=""
TRANSMITTER_DEVICE="/dev/lirc1"
TRANSMITTER_SOCKET=""
TRANSMITTER_LIRCD_CONF=""
TRANSMITTER_LIRCD_ARGS=""
...
...
</code>