Tackling Graceful Shutdowns on the GBZ

[Ganreizu]

Does it matter if the resistor is 1/2 watt or 1/4 watt?

[prerunnerseth]

Does it matter if the resistor is 1/2 watt or 1/4 watt?

No... its a weak pullup. the tiniest of resistors will do.

[Camble]

Yes, everything is shut off after the pi shuts down, but the powerboost stays always on (see the blue led)
It would be better if everything including the powerboost were shut off.

Ah, I didn't realise that. I'm assuming there will be a way to do that. I haven't got my supply yet.

[Fleder]

Yes, everything is shut off after the pi shuts down, but the powerboost stays always on (see the blue led)
It would be better if everything including the powerboost were shut off.

You could add another slide switch, which physically disconnects the battery from the powerboost.

[SidSilver]

Yes, everything is shut off after the pi shuts down, but the powerboost stays always on (see the blue led)
It would be better if everything including the powerboost were shut off.

You could add another slide switch, which physically disconnects the battery from the powerboost.

It's a good idea
Replacing the emergency reset button by a slide switch to physically shut off the power.

[Camble]

Well according to AdaFruit, the Power boost only draws 20uA when off, so might not be such a big issue.

The cheap alternative supply uses 180uA. Still not much, but quite a difference.

[fcn]

[spoiler=]

I soldered mine directly on my PI. I would take a photo of it but wrapped it in heat shrink so it would be a very uninteresting photo. Also, I dont think it makes sense to put it on that power strip because its quite far away from the pi which is where it's going to be going

It's pretty simple though.

Take a wire and solder it onto the Low Battery LED on the Powerboost.

Attach the other end of the wire to a 47K resistor.

Attach the other end of the 47k resistor to the base of the transistor (the middle pin).

Now if you have the flat side of the transistor facing towards to you, the collector is on the left and the emitter is on the right. Attach the collector on the left to the GND pin on the Pi and the emitter on the right to GPIO17

That should be it.

Follow my the wiring diagram when in doubt.

Oh so you don't even need a breadboard or anything. Sounds super simple, thanks for the help. Gotta find that transistor now and i'm all good haha.

Nope, exactly. I bent the pins of the transistor to fit the GPIO sockets and soldered everything directly onto my PI. That's what I was using in my prototype that you see in the videos

[/spoiler]

But the polulu switch is still necessary, right?

[Popcorn]

[spoiler=]

Oh so you don't even need a breadboard or anything. Sounds super simple, thanks for the help. Gotta find that transistor now and i'm all good haha.

Nope, exactly. I bent the pins of the transistor to fit the GPIO sockets and soldered everything directly onto my PI. That's what I was using in my prototype that you see in the videos

[/spoiler]

But the polulu switch is still necessary, right?

Yes, this is what you are using to shut everything off via GPIO signal

[Popcorn]

Now if you have the flat side of the transistor facing towards to you, the collector is on the left and the emitter is on the right.

I only see this now, but I thought for 2N3904 it was the opposite ? Emitter on the left & collector on the right.
https://www.sparkfun.com/datasheets/Com ... 2N3904.pdf
This is the way I wired and it seems to be ok.

Bubble is totally right!! Follow that. Apparently, I can't read. Lol

[Bubble]

Genius also do mistakes from time to time