Turn on Pi using keyboard, controller or phone
Can a Pi 3B be turned on using either a wired keyboard, wired USB snes pad, wireless 360 controller or a mobile phone?
My Pi is kept behind my TV and it is a pain to keep turning on /off so Im trying to find an easier method.
I searched and found a similar question regarding a 360 pad but that was over a year old and not much response on it.
When you supply power (via the USB connector) to the Pi, it will turn on. After use, you can switch it to a low power mode using
sudo shutdown -nowbut that is not really turning it off, just safe to remove the power (unplugging it). Very similar to a standby mode, except that you will need to supply power to one of the GPIO pins to have the pi wake up, as opposed to using a remote control.
Now, turning it on via whatever interface, means what exactly? You want to be able to wake it up from the low power mode, or you want to supply power to it using this interface? You could maybe fabricobble an ardiuno-setup that drives a relais circuit connecting/cutting the power based on whatever input, but I have the feeling you are aiming for something less involved. Maybe something like this will work for your setup?
I think the OP would like to choose some kind of low power sleep mode in ES to "shutdown" the Pi, but not completely turn it off. And then OP wants to be able to wake up the Pi simply by pressing a key on an attached keyboard, just like how you wake up a Windows computer or Mac.
I don't understand why a special hardware should be needed, but I am also confused why there seems to be no simple software option to enable such behavior? In fact such behavior should be the default to safe power with sleep, and allow easy wake-up by pressing space or any key or clicking the mouse, just like is has been on any PC or Laptop for a decade, and such is the default on pretty much all set-top boxes like Roku, and consoles like PS4 and Xbox One consoles, too. However, on those, it is a button on the remote or wireless controller that wakes up the device, not an attached keyboard. Using an attached keyboard should be simpler, since Bluetooth is not required to be kept on.
EDIT: Apparently, in order to save cost as much as possible, the Raspberry Pi board has no power management whatsoever, e.g. no sleep/suspend modes, no wake-up, nothing compared to what is found in most other modern hardware. There are a few add-on boards that provide such power management, such as sleepy-pi or witty-pi, but bottom line, there seems to be no easy way to do what the OP requested.