Tackling Graceful Shutdowns on the GBZ

[Zeke2040]

Well my boards came in and I made a mistake . I used a different package of mybpushbutton controller than tested with and it seems one of the missing pins was actually needed. I'll have to order more

Ugh! Sorry to hear that. Looking forward to seeing it come together.

[Popcorn]

Ok, here's the Power and Battery monitor finished. I've been testing it out and it works quite well.

Firstly, follow this wiring diagram. Here I'm using the Pololu Mini Slide Switch LV.



PLEASE NOTE: In the diagram, the Pololu's built-in slide switch is set to On, this is from their website. We need this always in the OFF position.

For the software monitor, you'll need to use SSH and log onto the Pi. Default user PI and password "raspberry"

You should be able to do this if you have a Wifi adapter on the Pi Zero and then connect from a computer on the same Wifi network. (Use Putty on PCs)

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ssh pi@retropie.local

At the command prompt, making sure you are the Pi user, type this to download the monitor and the videos:

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cd ~;git clone https://github.com/NullCorn/GBZ-Power-Monitor.git

You can then test it out by issuing this command:

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python ~/GBZ-Power-Monitor/gbz_power_monitor.py

Once you are satisfied that it detects your power switch and the low battery warnings, you can add it to the startup easily using the crontab of the pi user. I chose this method rather than messing with services because you'd don't have to be the root user.

Simply enter this line on the command prompt to add the monitor on startup.

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echo "@reboot     /usr/bin/nice -n 19 /usr/bin/python ~/GBZ-Power-Monitor/gbz_power_monitor.py" >> mycron; crontab mycron;rm mycron

Videos of it in action

https://www.youtube.com/watch?v=TRkEfD04unk
Low Battery Warning

https://www.youtube.com/watch?v=nRJ42oSrIg4
Power Switch test

Let me know how it works for you guys.

[Fleder]

@[mention]Popcorn[/mention]
I am sorry, i am sure this was already answered, but will the push button switch work as well instead of the slide switch?

[Popcorn]

@[mention]Popcorn[/mention]
I am sorry, i am sure this was already answered, but will the push button switch work as well instead of the slide switch?

Yes, the push button will work. Put UART TX to CTRL. Everything else should be wired the same. We can also use the OFF pin and GPIO-Poweroff but CTRL should work fine.

[SidSilver]

Is it possible to use the pololu's board switch as main switch instead of adding another ?

[Popcorn]

Is it possible to use the pololu's board switch as main switch instead of adding another ?

If you mean the on-board switch, it's super super tiny and won't work with the original DMG power switch.

If you mean the Emergency Latching Switch is not actually mandatory, but I recommend it just in case. It's there in the event of a kernel panic or some other condition where the monitor fails to power the pololu off. It's also there to disconnect the batteries when putting away the unit for longer periods.

[prerunnerseth]

I've fixed my boards and ordered another the second revision. I was also able to make the board a little smaller. I did confirm by hacking in the correct package that they will function as intended.

[SidSilver]

Is it possible to use the pololu's board switch as main switch instead of adding another ?

If you mean the on-board switch, it's super super tiny and won't work with the original DMG power switch.

Ok. Thanks. I didn't realize the actual size of the on-board switch.

Final question, can you remember me what is the transistor for ?

[Popcorn]

Just found a small bug that will prevent the videos from playing on the Low Battery warnings. If you cloned the git repository before now, do this to grab the latest version. Sorry.

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cd ~/GBZ-Power-Monitor;git pull origin master

If you are reading this and haven't grab it previously, then you don't need to do this. (Although doing it never hurts to be up-to-date)

[Popcorn]

Is it possible to use the pololu's board switch as main switch instead of adding another ?

If you mean the on-board switch, it's super super tiny and won't work with the original DMG power switch.

Ok. Thanks. I didn't realize the actual size of the on-board switch.

Final question, can you remember me what is the transistor for ?

It acts like a simple switch. When the Low Battery LED saturates the transistor, it pulls the GPIO line low and our monitor detects that. When it's not, it's pulled high. Since the voltage on the LED is variable, this is the safest way to know for sure that there is a Low Battery condition.