thedominik
Posts: 2
Joined: Thu Apr 19, 2018 11:49 am

Start Up Shutdown Button

Thu Apr 19, 2018 12:46 pm

Hey guys,

need your help for a start up and shut-down push-button. There is an easier solution with waking up the Pi with GPIO 5 and switch off with the same port by a short python script. But there is a problem: It shouldn´t start with connecting the power supply.

I had an idea with an thyristor. Using a push-button to ignite the thyristor. And afterwards a python script is going to shut down the Pi due to the next status of the button... But, there arise a few questions:
- The Pi still needs some Ampere during switched off. With which Thyristor it´ll change even though to the blocking state again?
I think the current is still to high to get a tiny thyristor for it??
- Does my circuit in attachment makes sense to solve this?
- Maybe there is another idea? without an external micro controller?

Thanks from Germany already :)

Dominik
Attachments
StartupShutdown2.png
StartupShutdown2.png (247.74 KiB) Viewed 181 times

thedominik
Posts: 2
Joined: Thu Apr 19, 2018 11:49 am

Re: Start Up Shutdown Button

Wed Apr 25, 2018 5:35 am

Got a solution with a LTC2954 for instance.
Therefore is a problem. The Pi has to show the LTC2954 that he started within 512 ms with pulling the KILL pin to HIGH.

Is there a possibility, a GPIO changes within 512 ms its status during booting?

After shutdown the Pi has to Pull it to LOW again for removing the supply voltage by the LTC...

best regards

dominik

Return to “Advanced users”

Who is online

Users browsing this forum: Baidu [Spider] and 19 guests