ESP8266 Community Forum

- Thu Feb 01, 2018 10:01 am #73635 Hi,
my question is probably easy to answer since such projects have been done on a frequent base. I just want to implement a remote power control for a PC with a web interface. Sounds pretty simple and straightforward.

However I'm wondering if I really need mechanical relays to power-switch/reset a PC mainboard using a ESP8266 module board like (mini) NodeMcu or if I could just use some sort of semiconductor components to shorten those power-switch/reset pins. My electronics knowledge doesn't go deep enough to figure out if I could maybe use a simple tranistor (this just came into my mind) or similar since the ESP8266 board is driven by the same power supply (which probably might not the crucial point).

- Fri Feb 02, 2018 3:14 am #73642 of course you can just use a simple transistor (with base resistor) to activate "power_sw" or "reset_sw" on your motherboards front panel connector.
They usually only short that pin to gnd. You'd have to supply the esp from +5VSB of the power connector.

- Fri Feb 02, 2018 8:23 am #73651 One thing you might not know about is that a lot of computers have a way to wake up the machine by sending a special packet to the machine. Wake up on LAN is a search term to find more information.

I send a UDP packet to the machine in a different room and it starts up and then is available on my network.

https://www.howtogeek.com/70374/how-to- ... enable-it/

- Tue Feb 06, 2018 1:36 pm #73755 I'm aware of the wake-on-lan functionality. The Thing is that you need some kind of portal on an extra server or the router itself to sned away the WOL packet to the MAC address.

I developed such an internal WOL Portal for my company and wrote it completely in PHP. The advantage there is that we have many servers there running 24x7 and I just needed to deploy it on one of our internal webservers.

The next disadvantage on today's computers is that they removed the WOL feature from the BIOS and Windows has to take care of waking up the PC. Also you are not allowed to shut down the machine but furthermore put it to sleep-mode (which can be forgotten in a hurry).

My idea was just to have a robust way to have some remote-hands while I'm not at home to ensure I can power-on or hard-reset my PC no matter in which state it is.

Since I'm not so good at electronics could I ask for some schematic draft how to connect the transistor and resistor and which electronic component I have to get for that?

Thank you in advance!