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Comment by why_at | Hacker News Reader

Related: I have a setup with a PC connected to my TV, it would be nice if there was some way to wake up my PC from sleep using a remote control of some kind. The best way I can think of is using wake-on-lan on another device like a raspberry pi. I could configure it to send the signal when it sees me push a button on my remote.

This doesn't feel very optimal though. Having a whole other device constantly running just to wake up my main device feels like a waste.

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I think if you have recent (not sure how recent?) HDMI ports, you can do this via a HDMI cable, which you might already use for displaying purposes? Never encountered it myself until I recently got a PS5 and noticed it and the TV shared both control and power state, so turning on the TV turned on the PS5 before I disabled HDMI CEC.

Alternatively, maybe there are adapters for HDMI that could add/emulate it/something similar?

I remember looking into this and it seems like a lot of motherboards/graphics cards don't support HDMI CEC for some reason.

That would be the ideal way if it worked though

Yeah, seems you're right. But! Seems there are a bunch of other hardware-related workarounds for getting CEC to maybe work, depending on the full setup you're using: https://wiki.archlinux.org/title/HDMI-CEC#Hardware_setup

For example:

> The PulseEight USB-CEC adapter works by passively extending all the pins of the HDMI connector on from the "PC side" connector to the "TV side" connector, save for the CEC pin, which is intercepted. The data going through that pin is instead exposed over a USB serial interface to let a PC control and monitor CEC traffic

Edit: Ah, but that adapter wouldn't work for powering on the PC I suppose, I don't think USB has something like WoL.

In firmware interfaces you can configure whether USB and PCI-E devices can wake up the computer. Enabling USB wakeup made it possible on my machine, that I can wake it up by pressing any key on the keyboard.

My solution is tied to Home Assistant, which is running for the whole house 24/7 anyway, then, a Z-Wave smart plug to turn the PC on/off, and, finally, an EnOcean kinetic battery-less switch to toggle it on and off. While we're at it, Home Assistant also powers on/off the TV, sets the input, sets volume, and dims the living room lights.

Grab an arduino Leonardo, micro, or any board that supports USB HID emulation. Throw on a simple IR receiver module and set it up to send a keypress when the power code comes through.

You might have to explicitly enable "allow this device to wake computer" in device manager.

As far as I'm aware, there's no special sauce here. Your motherboard should support leaving USB ports on and allowing wake from USB HID devices. I don't know of any consumer board from the modern era that doesn't support it.

Beyond that, you could just throw a relay across the power switch pins. Plenty of ways to skin this cat

> Having a whole other device constantly running just to wake up my main device feels like a waste.

Indeed, my first thought is the best place to run this is on an OpenWRT router. Perhaps as a package, or a builtin feature?

If you're already using microcontrollers, why not emulate a USB keyboard with one, and have an IR sensor that triggers a key press when it gets a signal?

The problem is that when it's asleep a key press won't wake it up. Only pushing the power button or using wake-on-lan will.

One thing I just thought to try is using an app on my phone to send the WOL packet.

Rewire the power button so it's an easy to push switch and put it behind a target. Then your remote can be a nerf gun.

Edit - the other thing that came to mind was to look into HDMI cec and see if there's a setup where turning on your tv will turn on the PC automatically.

Edit 2 - if you go with an app, you could use something like tasker and then you can have different triggers like your phone tapping an nfc sticker (then you don't have to unlock and find an app).

I find it unusual you have a device with a keyboard where the keyboard won't wake the computer. You must have some setting disabled for that to happen.

For Windows, maybe this helps. 1. Open Device Manager 2. Find the keyboard under "Keyboards" 3. Right-click and select "Properties" 4. Go to the "Power Management" tab 5. Make sure "Allow this device to wake the computer" is checked

This is probably the cause. It would be highly unusual for any modern motherboard to not support waking from USB HID at all.

I do this with a USB device that looks like a keyboard, but speaks CEC out the other end. TV turns on with the appropriate source selected, the keyboard sends a wake key.

I have this set up with a Flirc device. It listens for IR remote control keys and converts to ~keyboard keys. So the PC wakes up for the same reason a keyboard would wake it up. I can also control the PC that way, for watching movies and such. That's the main reason to do it actually, the waking up is just a bonus.

I did exactly this last year

    1. radio remote with usb dongle that emulates a keyboard, so usual wake-on-keypress wakes up the machine
    2. systemd unit that when sleep ends sends "power on" to TV via IR blaster

works lovely

Why not from your phone? I wake up my kodi pc with a remote that supports WOL.

Tiny PSA: The official Kodi app (at least on iOS) has built-in WOL commands.

Yeah I just thought of this, gonna give it a try today

I had an IR remote that was set up to wake my Kodi box on button press. Seems very doable.

If you are on same network you can use Wake on Lan android app.

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