Igor's Blog
Programming, DIY, Games, Hacks, and Tech

I went to the trouble of making an external power button for my Odroid XU4 and then found out that out of the box DietPi completely ignores this button being pressed. Luckily there is a way to make the OS shut down after the power button is pressed.
odroid_shutdown.jpg


Here's what I did to check if the power button presses do anything. I needed to install evtest first.
 Commands
apt-get install evtest


After it was installed, I ran it and got the following output:
 evtest
No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0: gpio_keys.7
/dev/input/event1: ADS7846 Touchscreen
/dev/input/event2: UVC Camera (046d:0825)


Selecting '0' gave me this...
 0
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100
Input device name: "gpio_keys.7"
Supported events:
Event type 0 (EV_SYN)
Event type 1 (EV_KEY)
Event code 116 (KEY_POWER)
Properties:
Testing ... (interrupt to exit)


...and when I triggered the power button, a bunch of events were fired, so I was on the right track!
 Events
Event: time 1474075323.624805, type 1 (EV_KEY), code 116 (KEY_POWER), value 1
Event: time 1474075323.624805, -------------- EV_SYN ------------
Event: time 1474075323.829555, type 1 (EV_KEY), code 116 (KEY_POWER), value 0
Event: time 1474075323.829555, -------------- EV_SYN ------------




I came across this forum post that gave me some good leads, but it wasn't for an XU4, so using the default systemd power switch rules I came up with something that should work on the XU4...
 /etc/udev/rules.d/70-power-switch-odroidxu4.rules
ACTION=="remove", GOTO="power_switch_end"
SUBSYSTEM=="input", KERNEL=="event*", SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", ATTRS{keys}=="*,116|116,*|116|*,116,*", TAG+="power-switch"
LABEL="power_switch_end"


The above was saved to /etc/udev/rules.d/70-power-switch-odroidxu4.rules and then I ran the following commands to reload the rules...
 Commands
systemctl restart systemd-udevd
udevadm trigger


Then as soon as I triggered the power button, my XU4 started shutting down. Neat!

-i

Please leave your comments or feedback below!
comments powered by Disqus
Other posts you may like...

Recent Blog Posts

How to enable the full stack trace in Maven's Surefire plugin for JUnit testing

Twelve elements of the Burst Mining Pool interface explained

TPG FTTB settings for the Billion BiPAC 8700AXL 1600 modem router

Protecting old Atari Lynx game boxes with snug fit plastic sleeves

How to fix SoapUI javax.net.ssl.SSLHandshakeException calling WebLogic 12.2 web services on Java 8

Woolworths (WOW) shares disappeared from Computer Share Investor Centre

Connecting the Dell UltraSharp U3415W monitor to a MacBookPro via USB-C

How to add/change PHP versions appearing in MAMP preferences

Fix the ORA-00904: ORA_ROWSCN: invalid identifier error in SQLDeveloper with a few easy steps

G Suite Gmail is broken on Safari due to new Google Content Security Policy settings

Recent Galleries

Protecting old Atari Lynx game boxes with snug fit plastic sleeves

Monument Valley 2 is released and does not disappoint

Space Food - Chocolate Ice Cream with Chocolate Chips

Legeod Star Wars AT-DP kit

DIY spare parts computer build with a RAIDMAX Anura case

Fake 'Lepin' brand Lego packaging

Hardwood garden bench with clear resin void filler

Fixing a 3D printer extruder that stopped heating up

Easily increase disk space in a Lenovo Ideapad 100S 14" laptop with an M.2 SSD

Making a multi-piece 3D printed solder spool holder stand

My Other Web Sites

Igor and Elise's Travels
Riverside Expressway Cam
300 George St Blogumentary

My Online Tools

UUID to OID Converter
Guru JSON-RPC Tester
Extrudifier Object Designer
Travel ┬ÁBlog

Blogs and Friends

Matt Moores Blog
Georgi's FlatPress Guide
Perplexing Permutations
The Security Sleuth
Ilia Rogatchevski
Travelling Fairy

Blog Activity

Blog Activity
Don't forget to
my Facebook page for more great articles!
Don't show this again