Power switch circuit

[pine.tree]

When you guys say 'switch' ... do you mean the physical component that toggles?

So... the on/off switch of the classic Gameboy serves this purpose, and no additional component is needed to make use of on/off functionality?

Yes, the physical switch where you can turn on / off the Pine.
Currently on the board, there are connections for it, but no physical switch soldered on.

It was supposed to come as a stretch goal reward but there were some people who were negative about having the switch, thus it is now dangling in the air.

I don't see why they cannot have the switch there, and just leave it in the 'on' position if they do not want to use it?
I would love to see the switch there, so that I can turn on/off the Pine as and when I want, rather than pulling the power cable off... 

I definitely agree. A switch would be great, i would love not to have to pull out cords or something, just a little flick of a switch is what i would prefer. If Pine decides not to include a power switch, you can always take a broken flashlight apart and use the click switch

I believe the switch that's on the board is actually a momentary contact that's connected to the PMIC.  A short press of the switch when the system is running generates an interrupt to the SoC from the PMIC, causing a soft power off with a graceful system shutdown.  A long hold (16 secs according to the AXP803 PMIC datasheet) forces the PMIC into a powered-off state, where it just shuts off the power to everything.

Pressing the power button when the board is off powers on the PMIC, which powers up all the devices on the board.

Ah, that would be great. I forgot about the ability to either force shutdown or "gracefully" shutdown the device. I certainly wouldn't want to abruptly cut power, shutting down properly is good. If they do the momentary contact switch, 10/10.

[Gearsoul]

I believe the switch that's on the board is actually a momentary contact that's connected to the PMIC.  A short press of the switch when the system is running generates an interrupt to the SoC from the PMIC, causing a soft power off with a graceful system shutdown.  A long hold (16 secs according to the AXP803 PMIC datasheet) forces the PMIC into a powered-off state, where it just shuts off the power to everything.

Pressing the power button when the board is off powers on the PMIC, which powers up all the devices on the board.

Ah, that would be great. I forgot about the ability to either force shutdown or "gracefully" shutdown the device. I certainly wouldn't want to abruptly cut power, shutting down properly is good. If they do the momentary contact switch, 10/10.

... :/c Huh, so... if I use the Gameboy power switch, I'll actually be forcing a hard shutdown instead of the 'graceful' soft shutdown? That sounds like it would be bad? Maybe... if I only turn it off after closing everything it would be okay..?

[Ghost]

I believe the switch that's on the board is actually a momentary contact that's connected to the PMIC.  A short press of the switch when the system is running generates an interrupt to the SoC from the PMIC, causing a soft power off with a graceful system shutdown.  A long hold (16 secs according to the AXP803 PMIC datasheet) forces the PMIC into a powered-off state, where it just shuts off the power to everything.

Pressing the power button when the board is off powers on the PMIC, which powers up all the devices on the board.

Ah, that would be great. I forgot about the ability to either force shutdown or "gracefully" shutdown the device. I certainly wouldn't want to abruptly cut power, shutting down properly is good. If they do the momentary contact switch, 10/10.

... :/c Huh, so... if I use the Gameboy power switch, I'll actually be forcing a hard shutdown instead of the 'graceful' soft shutdown? That sounds like it would be bad? Maybe... if I only turn it off after closing everything it would be okay..?

Ah! This is a good point. I think the Gameboy uses a hard on/off switch rather than a momentary power switch.

But we will figure out a solution to this, no worries

[joe]

I believe the switch that's on the board is actually a momentary contact that's connected to the PMIC.  A short press of the switch when the system is running generates an interrupt to the SoC from the PMIC, causing a soft power off with a graceful system shutdown.  A long hold (16 secs according to the AXP803 PMIC datasheet) forces the PMIC into a powered-off state, where it just shuts off the power to everything.

Pressing the power button when the board is off powers on the PMIC, which powers up all the devices on the board.

Ah, that would be great. I forgot about the ability to either force shutdown or "gracefully" shutdown the device. I certainly wouldn't want to abruptly cut power, shutting down properly is good. If they do the momentary contact switch, 10/10.

... :/c Huh, so... if I use the Gameboy power switch, I'll actually be forcing a hard shutdown instead of the 'graceful' soft shutdown? That sounds like it would be bad? Maybe... if I only turn it off after closing everything it would be okay..?

Hardware maybe this pine64 have not shutdown , 

but software android have .
https://play.google.com/store/search?q=shutdown&c=apps

For Linux , have command set time to shutdown your pine64 and mouse can shutdown your pine64 , this is not problem

[Gearsoul]

... How big is the connector area?

Even though the switch seems to have a hard, 'one or the other' feel to it, feeling it out on my Gameboy you *can* actually slide it carefully to sit in the middle... Though it requires a lot more 'effort' to not simply click it into place.

Perhaps if the button weren't so snugly in place it would be easier to make use of a momentary contact? Of course this could lead to other problems if not done correctly.

[Ghost]

... How big is the connector area?

Even though the switch seems to have a hard, 'one or the other' feel to it, feeling it out on my Gameboy you *can* actually slide it carefully to sit in the middle... Though it requires a lot more 'effort' to not simply click it into place.

Perhaps if the button weren't so snugly in place it would be easier to make use of a momentary contact? Of course this could lead to other problems if not done correctly.

Unfortunately, the Gameboy doesn't recognise that middle setting as anything. It will only ever be on or off. It doesn't mean we can't modify the switch, though. It's a small issue.

Like joe says (thanks joe), power shutdown can be accomplished by software, but our aim is to have an emulator that boots straight into the emulator and uses only the face buttons of the Gameboy to function. So we do not want (ultimately) to be encumbered with things like mice and keyboards...

[Gearsoul]

Indeed!

I had though perhaps if the switch could be partially slid it could be clicked into place to make the shutdown contact and then slid to the middle to avoid a hard shut down and avoid the on switch portion of contact.

[Ghost]

Indeed!

I had though perhaps if the switch could be partially slid it could be clicked into place to make the shutdown contact and then slid to the middle to avoid a hard shut down and avoid the on switch portion of contact.

Yes, that would probably work, but it would hardly be ideal having to fiddle with the switch to find that middle position. Better perhaps to replace the original switch with a similarly sized and shaped momentary version...

[janjwerner]

I was recycling some home appliances and found some tactile switches. Found a new home for them - Pine
Pressing power button for 15 seconds do hard power off, short press of power currently does nothing under Linux (investigating now), reset works just as intended. 
Heatsinks are from RPi, they are bit small, still better than nothing.

[MichaelMeissner]

From the picture, it looks like this Adafruit tactile switch (https://www.adafruit.com/products/1489).

Pololu.com also sells a similar tactile switch: https://www.pololu.com/product/1400.

I'm sure you can find these cheaper elsewhere, but if you are ordering things from Adafruit or Pololu, consider adding a pack of these to your next order.