common:application_note:gpio:lirc_gpio_blaster

'ODROID-N2' on this page refers to the ODROID-N2 series (N2, N2+, N2L).

Support GPIO based IR Blaster

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) or higher. (available on kernel 3.10 with 3.10.104-126 (Nov 29, 2016))
  • ODROID-N2 : A new version including LIRC TX will be released.
  • ODROID-C4 : A new version including LIRC TX will be released.

This is a schematic example for connecting the IR LED to a GPIO output.

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 testing.

  • 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.)


ODROID-N2

ODROID-N2 using 40Pins Expansion Connector

For example, Pin #15 (GPIO #483) 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 #15 - GPIOX.BIT7, GPIO #483

Please refer to this link that describes expansion connectors of ODROID-N2.
ODROID-N2 Expansion Connectors

ODROID-C4

ODROID-C4 using 40Pins Expansion Connector

For example, Pin #13 (GPIO #480) 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 #13 - GPIOX.BIT4, GPIO #480

Please refer to this link that describes expansion connectors of ODROID-C4.
ODROID-C4 Expansion Connectors

ODROID-C2

ODROID-C2 using 40Pins Expansion Connector

For example, Pin #11 (GPIO #247) 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 #11 - GPIOX.BIT19, GPIO #247

Please refer to this link that describes expansion connectors of ODROID-C2.
ODROID-C2 Expansion Connectors

ODROID-C1/C1+

ODROID-C1/c1+ using 40Pins Expansion Connector

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

Please refer to this link that describes expansion connectors of ODROID-C1/C1+.
ODROID-C1/C1+ Expansion Connectors

If 1-wire driver is taking over GPIO Pin 24, you have to unload the 1-wire drivers first. blacklisting 1-wire drivers

target
$ sudo rmmod w1_gpio
$ sudo rmmod wire
ODROID-XU4

ODROID-XU4 using 2x15Pins Expansion Connector

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.

Please refer to this link that describes expansion connectors of ODROID-XU4.
ODROID-XU4 Expansion Connectors

LIRC version of Ubuntu 18.04 is higher than Ubuntu 16.04 and related files under /etc/lirc/ are configured differently.
Select your Ubuntu version first.

  • common/application_note/gpio/lirc_gpio_blaster.txt
  • Last modified: 2022/11/08 14:36
  • by luke.go