Tackling Graceful Shutdowns on the GBZ

[dirtybeagles]

You are right. This probably belongs in the guides section now that it's complete. The only question is which guide section? hardware or software?

I would suggest hardware.

Is there an option to just run a script to just display the low battery if you don't have the hardware? If so I would put that in software and just note you could combine both.

[Ganreizu]

[mention]Popcorn[/mention] Can you explain and/or post pics of how to make the part of the switch with the resistor? You use a breadboard like in part 4 of the guide and put the resistor and what else on it? Can we combine this board with the power board from part 4?

[Popcorn]

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.

[Bubble]

I've put the transistor and the resistor on a breadboard, but I have room to waste on my build ^^

Sorry for the poor quality picture, wich was extracted from a video.

[SidSilver]

Pardon me if the question has already been asked but, with this wiring, the powerboost is always "On".
Is it ok like that ? Won't it discharge the battery slowly or lower the lifetime of the powerboost ?

[Camble]

Pardon me if the question has already been asked but, with this wiring, the powerboost is always "On".
Is it ok like that ? Won't it discharge the battery slowly or lower the lifetime of the powerboost ?

The point of this setup is so that the power supply is off when the Pi shuts down.

[SidSilver]

Pardon me if the question has already been asked but, with this wiring, the powerboost is always "On".
Is it ok like that ? Won't it discharge the battery slowly or lower the lifetime of the powerboost ?

The point of this setup is so that the power supply is off when the Pi shuts down.

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.

[Ganreizu]

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.

[Popcorn]

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

[Bubble]

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.