Looking for a sleek RaspberryPi enclosure that also fits the ATXRaspi smart Pi power controller and a power button? Check this awesome case from C4Labs which is designed to fit the ATXRaspi along with a power button for shutdown/reboot:

It includes a bunch of accessories like the power button, heatsinks and rubber feet. Made in the great again USA. Check out the new ATXRaspi Guide for the latest updates which include the ability to use both momentary and latching switches!

If you want to automatically power off your Pi when you run the shutdown command (ex. shutdown menu in xbmc), this can be done pretty easily through a small addition to the ATXRaspi circuit. Basically we need to tell ATXRaspi to issue a shutdown, from software rather than from the button press. We can simulate the power button press usgin a NPN transistor from any Pi GPIO. Below is an illustration how this can be done with GPIO10:Please note: this only works for momentary button operation. It will not work in latching/slide switch mode.

Here’s a sample script that should run when you want to shutdown or reboot your Pi, save this script as /usr/bin/local/softshutdown.sh:

#!/bin/bash
BUTTON=10

#setup GPIO 10 as output and set to HIGH
echo "$BUTTON" > /sys/class/gpio/export;
echo "out" > /sys/class/gpio/gpio$BUTTON/direction
echo "1" > /sys/class/gpio/gpio$BUTTON/value

#keep GPIO 10 high for at least 4 seconds for shutdown, 1s for reboot (same as pressing ATXRaspi button)
SLEEP=${1:-4} #default to 4 seconds if no delay value was passed

re='^[0-9\.]+$'
if ! [[ $SLEEP =~ $re ]] ; then
   echo "error: sleep time not a number" >&2; exit 1
fi

echo "ATXRaspi button press for: $SLEEP seconds..."
/bin/sleep $SLEEP

#restore GPIO 10
echo "0" > /sys/class/gpio/gpio$BUTTON/value

Make it executable with sudo chmod +x softshutdown.sh, then the permissions on this script should be the following:

pi@raspberrypi3:/usr/local/bin $ ls -la
-rwxr-xr-x  1 root staff  580 Dec 29 17:59 softshutdown.sh

Since /usr/local/bin is in your PATH variable (check with printenv command) you can now execute/edit the softshutdown.sh from anywhere). Also note this script takes a single decimal/numeric variable which represents the delay of the “button press”, if no value is given then the default is 4 (seconds), and this simulates a shutdown. For a reboot, pass a value of 1: softshutdown.sh 1.

Let’s do something cool and create aliases to execute shutdown and reboot in raspbian, run the following (use your own custom alias if you’d like):

$ printf "%s\n" "alias atxshutdown='sudo shutdown.sh'" >> ~/.bashrc
$ printf "%s\n" "alias atxreboot='sudo shutdown.sh 1'" >> ~/.bashrc
$ source ~/.bashrc

This adds permanent aliases to your .bashrc file and activates them. Now you can run these commands from anywhere:

• atxreboot to trigger a reboot – ATXRaspi status LED will blink and wait for Pi to reboot
• atxshutdown to trigger a shutdown – ATXRaspi button status LED pulses until Pi is halted, then it cuts power off as usual!

Using with XBMC

For XBMC you can do it somewhat simpler since there is a shutdown menu which invokes a shutdown command that can be replaced with invoking a custom script. You can use the following equivalent script, save it as /home/pi/softshutdown.sh:

#!/bin/bash
sudo gpio -g mode 10 out;
sudo gpio -g write 10 1;
sleep 4;
sudo gpio -g write 10 0

Next modify this file: /opt/xbmc-bcm/xbmc-bin/share/xbmc/addons/skin.confluence/720p/DialogButtonMenu.xml, and in the “Shutdown description” section replace XBMC.Powerdown() with System.Exec(“/home/pi/softshutdown.sh”). You may need a reboot for this to take effect. Now when you shutdown XBMC, the transistor will simulate shutting down from ATXRaspi, and will power off your Pi as usual !

This was also posted as a guide here, and was inspired from this forum thread, thanks to all contributors!

This is a summary of some load tests I did on the ATXRaspi. People often ask: How much load can the ATXRaspi support?

I used the following hardware, and I wanted to see how much current the official DSI display will draw in addition to the Pi.

• RaspberryPi3, Model B v1.2 (Raspbian Jessie, no overclocking)
• small 0.2A fan that is a popular accessory and often used with the Pi
• the official Pi Foundation DSI Display

I threw in the 0.2A fan just to put an extra strain on the power supplies. Here are the 3 supplies I tried, and while all could run this setup without instability issues, the Under Voltage Warning (UVW) would come up at times, especially on the Apple supply which would show it constantly and the 5V GPIO rail would stay at ~4.8V. The best was the CanaKit 5V/2.5A, with this supply the UVW would only appear intermittently during boot, and would settle at ~5.05V after boot. So the CanaKit supply was used for the following tests.

The trusty Fluke 87V was used to measure the LCD amps and the GPIO 5V rail during boot to a console. Here is the setup and average mAmps used by the LCD at boot time:

Here are the peak recorded mAmps used by the LCD, note that this MAX was registered during (re)booting. The Pi LCD settles to ~450mA after booting is complete.

And here are the measured Volts with the CanaKit 5v/2.5A supply, again note that the 4.93V was recording during booting, after which it settles to ~5.0V:

A basic scope roll measurement was done to look at any MIN/MAX peaks and overall 5V rail behavior, note how the voltage starts at ~5.2V then the LCD starts up and voltage goes to a stable ~5V where it settles during/after boot, otherwise no odd dips or spikes:

Here is the Under Voltage Warning that might show up. With the CanaKit supply this showed intermittently only during boot. With the other supplies it was more apparent and with the Apple supply it was constantly showing all the time. Without the LCD this warning would never show with the CanaKit supply, but would show with the others.

Even so, the Pi behaved normally with all these supplies and there was no observed instability.

According to official Pi release notes, the UVW shows when the 5V voltage rail drops below 4.65V. In the tests above this condition could not be recorded with any of the supplies tested, either with an oscilloscope (roll 128ksps) or with the Fluke87V in Voltage Peak Detect Mode (1ksps+). Even with the worst performer (Apple supply) the MIN peak  was around 4.7V and settled around 4.85V after boot.

The conclusion is that ATXRaspi supports quite a hefty load, but to avoid the Under Voltage Warning you really need a very good supply, at least 2.5A.

This content was also posted under the official ATXRaspi Guide.