Tackling Graceful Shutdowns on the GBZ

[Popcorn]

Actually, there is voltage on the LBO pin. And also surprising on the EN pin too! It goes up to VBAT. You certainly can't map that to a GPIO. I came up with a working solution to the last remaining piece of mine.

I replaced the planned "reset button" with an actual latching on/off button. Lol. That will be recessed so it can't be hit unintentionally. This is to allow you to do manual reset but also to be able to disconnect the battery from the Powerboost, if you are putting away the unit for longer periods of time.

So think of the main power slide switch now as ON/STANDBY. Where the latching switch is a physical disconnect of the batteries.

I realized that without the EN pin closed, there will always be a little draw off the batteries, even if it's to power that little blue led of powerboost and nothing else, regardless, it's some draw. And leaving the unit on "STANDBY" for long periods of time will eventually drain the battery. This is the only solution, since any solution using an electronic switch to close EN either is drawing off the batteries too and adding more components.

I'm cool with this. It solves everything and gives us our graceful shutdowns the way we want.

[prerunnerseth]

Actually, there is voltage on the LBO pin. And also surprising on the EN pin too! It goes up to VBAT. You certainly can't map that to a GPIO. I came up with a working solution to the last remaining piece of mine.

I replaced the planned "reset button" with an actual latching on/off button. Lol. That will be recessed so it can't be hit unintentionally. This is to allow you to do manual reset but also to be able to disconnect the battery from the Powerboost, if you are putting away the unit for longer periods of time.

So think of the main power slide switch now as ON/STANDBY. Where the latching switch is a physical disconnect of the batteries.

I realized that without the EN pin closed, there will always be a little draw off the batteries, even if it's to power that little blue led of powerboost and nothing else, regardless, it's some draw. And leaving the unit on "STANDBY" for long periods of time will eventually drain the battery. This is the only solution, since any solution using an electronic switch to close EN either is drawing off the batteries too and adding more components.

I'm cool with this. It solves everything and gives us our graceful shutdowns the way we want.

Did you remove the transistor and LED? There shouldnt be any voltage on an open collector output pin unless you put it there with a pull up of some sort. the Transistor used in this that circuit has a pull up built into it. If there is voltage on that pin with nothing connected to it. then it is just leakage internal to the chip and means its a bit of a poorly designed chip. None of our chips would have voltage on an open collector output pin. The EN pin also has a pull up on it that must be removed before the voltage will go away.

R13 and T1 need to be removed or pulled up to 3.3V instead of VBAT.

I still like the way of driving a NMOS or NPN with the LED side of this. This will be a much stronger pull down and keep you from losing the LED.

pullup.jpg (126.13 KiB) Viewed 8380 times

[Popcorn]

Sadly no. It was all working well, so I soldered and glued it directly onto the Pi. Now, I don't want to remove it at this point. I'll test it out on the second GBZ I build after this one though.

[SidSilver]

This little things are cheap, that's nice but not easy to find and the shipping fee are 3 time the price of the PCB...
I need to find this with low shipping to France !

[Popcorn]

This little things are cheap, that's nice but not easy to find and the shipping fee are 3 time the price of the PCB...
I need to find this with low shipping to France !

I bought my pololu switch from exp-tech.de. Shipping is reasonable.

[SidSilver]

This little things are cheap, that's nice but not easy to find and the shipping fee are 3 time the price of the PCB...
I need to find this with low shipping to France !

I bought my pololu switch from exp-tech.de. Shipping is reasonable.

exp-tech.de charges 9€ to France

The best i've found is Gotronic with 5,90€ fees to France.
http://www.gotronic.fr/art-module-inter ... -24232.htm
It makes the board to 9,90€ shipping included

[Synnth3t1k]

A little off topic, but with this way of shutting down, with an electronic switch. Is there a way to be able to have a "spring loaded" switch that you could flick it over and make the GBZ go into a sleep mode or stand by, instead of fully turning off? Kind of like a GameBoy SP.

[Popcorn]

A little off topic, but with this way of shutting down, with an electronic switch. Is there a way to be able to have a "spring loaded" switch that you could flick it over and make the GBZ go into a sleep mode or stand by, instead of fully turning off? Kind of like a GameBoy SP.

I took a cursory look at it before. It wouldn't work like a quick suspend that you are thinking about because the Pi still needs to do the shutdown and dismounting for it to safely shut off

However, it seems that retroarch does support game saving and loading from quit state. But I wasn't able to figure out how to trigger a save from a kill signal yet. If we can figure that out, it is possible that we could make it load some type of config file on the next boot This way it could boot back up to the last game state you were at. I need to explore this more, at least for retroarch. Not sure about the other emus.

I didn't dig into it too far because up until now, I was focused on the low level stuff. Lemme look into it.

[prerunnerseth]

My boards will be in today. Hope to find time to build one up and test today. If not I will come in to work tomorrow to do it. I'll post some pictures and video.

[prerunnerseth]

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