Tackling Graceful Shutdowns on the GBZ

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Camble
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Re: Tackling Graceful Shutdowns on the GBZ

Post by Camble » Fri Jul 29, 2016 10:26 am

@alien0matic How do you have the power hooked up for your screen?

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Re: Tackling Graceful Shutdowns on the GBZ

Post by alien0matic » Fri Jul 29, 2016 10:53 am

I made a small breakout board that everything gets its power from.

The problem seems to be that the GPIO is never pulled down because the transistor isn't "opening".

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Re: Tackling Graceful Shutdowns on the GBZ

Post by Camble » Fri Jul 29, 2016 11:19 am

You can use a simple voltage divider to reduce the LBO voltage to a safe level and wire that straight to a GPIO pin.

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Re: Tackling Graceful Shutdowns on the GBZ

Post by alien0matic » Fri Jul 29, 2016 12:10 pm

But the solution from this thread should work, too, shouldn't it? I have everything set up for this, would be good to get it working.

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Re: Tackling Graceful Shutdowns on the GBZ

Post by Camble » Fri Jul 29, 2016 3:29 pm

@alien0matic Yes. I'm just saying, there's a low battery output on the PowerBoost.

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Re: Tackling Graceful Shutdowns on the GBZ

Post by alien0matic » Sun Jul 31, 2016 5:26 am

Ok, I measured the voltage on the base pin of the transistor to be 0.58V when the LED is fully lit. Reading this https://www.sparkfun.com/datasheets/Com ... 2N3904.pdf the transistor will switch on 0.65V. Which means the voltage is too low. Should I just add another resistor with less Ohm? I already tried shorting the resistor, but that causes an instant shutdown.

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Re: Tackling Graceful Shutdowns on the GBZ

Post by Camble » Sun Jul 31, 2016 9:12 am

@alien0matic I don't know, I don't use that solution for low battery

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Re: Tackling Graceful Shutdowns on the GBZ

Post by Racerboy » Sun Jul 31, 2016 2:04 pm

Do you think you could design a circuit that uses a momentary power button instead of a throw switch?

I know you could just hook up a button to GPIO and configure it to shutdown the pi, but with the same button, could you power the pi back on again?
Colorado State University - Undergraduate Mechanical Engineer and Minor in Mathematics

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Re: Tackling Graceful Shutdowns on the GBZ

Post by Camble » Mon Aug 01, 2016 2:07 am

@Racerboy Check out this solution someone posted on page 1 of this thread. It works quite well.

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Re: Tackling Graceful Shutdowns on the GBZ

Post by hueblo » Mon Aug 01, 2016 1:38 pm

So just to be sure to turn off the 1000C using a secondary switch would have to be implemented instead of using a reset button?

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