Retroflag NESPi Case - Soft Power & Reset Hack

[Yahmez]

Hey guys,

Thought I'd share this little tutorial I made for adding soft shutdown and reset to the awesome Retroflag NESPi case.

https://drive.google.com/file/d/0B9AzTQWe_cTFem1JS01HVU1GMDg/view?usp=sharing

If you end up doing this mod, be sure to check out @meleu graceful ES shutdown method here: https://retropie.org.uk/forum/topic/12895/ensuring-es-gracefully-finish-and-save-metadata-in-every-system-shutdown

Enjoy!

[cyperghost]

@yahmez That's a good one.
Proper shutdown can be provided by these scripts here

[Yahmez]

@cyperghost In the tutorial linked, I provided a script specifically for this mosfet switch application.

[cyperghost]

@yahmez A checked your profile ;) You are a new member.
Welcome on board mate! And thank you for your nice posting about modding switches.

About the shutdown scripts... ES got the habit to not save metadata if it is not proper shutdowned. If you just perform a system reboot via SSH command or type killall emulationstation then indeed ES is closed but no metadata is saved. Metadata are those XML files that are used to store scraped data AND since ES 2.4.1 to save favorites and last played games. So it is important to have "Save metadata on exit" enabeled and to perform proper shutdowns.

You can get into touch with the topic by starting here

Script version 1.59 is the latest ...
So you have to change it a bit if you want to do a reboot via your switch but you will find out ;)

At this point I want to introduce @meleu, he's a well experienced coder and moreover a nice and friendly guy.

[Yahmez]

@cyperghost
Thanks for explaining that to me as I did not realize there were issues with saving the metadata. I'll look into fixing this in my python script.

Thank you!

[s33d1ing]

@Yahmez Thanks this is exactly what I was looking for!

[Renegade_R]

@yahmez Thanks for the very comprehensive tutorial, I am wondering, is there an alternative to using the momentary switch board for more somewhat common parts? Getting that board delivered to me would cost more than the NESPI case itself.

[mike17855]

Has the shut down script been updated in the walk through? With the 1.59 script noted above?

[DaminouTav]

Thanks @Yahmez !
I will receive my NesPi case at the end of september and will test that.
If I understand well, when you press Power, it sends an order to Raspberry via GPIO (and we can do what we would like with it, in this case a properly shutdown) and then, hard power off raspberry ? The mofset knows when it have to hard power off via "On Control" => When raspberry is off, GPIO is off then mofset can hard power off ? Am I right ? :)
I'm not sure to understand very well how it works in fact ^^

[cyperghost]

@daminoutav I tried to explaind the function shema here

[DaminouTav]

@cyperghost Thanks :)

[DaminouTav]

And what happens when we press "Reset" ?

[cyperghost]

@daminoutav Well...
Then happens whatever you want....
Remove the NesPi connector from it's original place and connect it to a free GPIO together with a pullup resistor .... then if you press reset you can

1. Restart ES
2. Restart the whole Pi
3. Send an eMail
4. Make a Screenshot.....

[DaminouTav]

@cyperghost Yeah in fact I meant "what happens on mofset aide". Because with power button it's shutdown Rpi which doesn't keep HIGH on gpio control, then mofset hard power off. When a reset is sent to the pi, gpio control can't be maintain anymore, and mofset should hard power off Rpi. How can it distinguish a power off and a reset ?

[cyperghost]

@daminoutav As @Yahmez cut the traces off the switches they work independent. On the mosfet side with reset and evenpower buttons happens nothing ;) Because they are not connected to the mosfet.... only the "POWER CONTROL" GPIO is directly connected to the mosfet and keeps the state on/off.

So you have power switch connected to GPIO X and reset to GPIO Y.
So the Pie "knows" which button is pressed and initiates different actions ;)

The original NesPi makes use of the reset buttons but that is an dirty reset method. Better use the software possibilities ;) RetroPie (better EmulationsStation) is able to perform proper Pie restarts, Pie shutdowns and ES restarts with a few tricks....

[DaminouTav]

@cyperghost ooh okay I understand :D thanks for explanations ! (And shame on me, I use Retropie competitor aha I tried it 2 years ago but I didn't like, have to test it again)

[bjose2345]

@cyperghost I have a doubt hope you maybe can help me there, im looking to use the reset button and programmed to trigger like if was a keyboard presses, somehitng like this

http://www.rcjoycon.com/cpjexr/

but for a GPIO solution, i saw it in this video

Any help any guide any suggest woul help me a lot, many thanks

[cyperghost]

@bjose2345 Sorry I've no clue what is done here....
There is a binary from adafruit that simulates keypresses via GPIO - I think that will work. Google is your friend...

Got it: https://learn.adafruit.com/retro-gaming-with-raspberry-pi/configuring-retrogame

[bjose2345]

@cyperghost Many thanks, i will look at this.

[Yahmez]

@cyperghost said in Retroflag NESPi Case - Soft Power & Reset Hack:

@daminoutav As @Yahmez cut the traces off the switches they work independent. On the mosfet side with reset and evenpower buttons happens nothing ;) Because they are not connected to the mosfet.... only the "POWER CONTROL" GPIO is directly connected to the mosfet and keeps the state on/off.

So you have power switch connected to GPIO X and reset to GPIO Y.
So the Pie "knows" which button is pressed and initiates different actions ;)

The original NesPi makes use of the reset buttons but that is an dirty reset method. Better use the software possibilities ;) RetroPie (better EmulationsStation) is able to perform proper Pie restarts, Pie shutdowns and ES restarts with a few tricks....

Not quite. The power button is connected to the mosfet too, so upon pushing the power button it activates the mosfet switch, powering up the pi. It will continue to keep the mosfet on as long as the power switch is on. As the pi boots, it supplies a second 'on signal' to the mosfet but only really matters or does anything when you switch off the power switch. At that point it is keeping the mosfet on until the pi safely shuts down.