[Guide] Graceful shutdown switch without Pololu [RETIRED]

[Camble]

Psst @Camble.. I think you mean GPIO 27 in orange above. Not 17.

Yea, that

[AerynSun]

For German GBZ builders (or maybe also european) this ebay seller has the right brand (Vishay Siliconix):
ebay.de

For that price I got like 50pcs fairchild JFETs, but at least now I have 5 of them, that should work. After building one working shutdown switch I can go crazy with the fairchild ones

[TechDante1]

this is amazing i think im going premade tho as im not too great with soldering have a bit of a hit and miss when it come s to it

[Camble]

this is amazing i think im going premade tho as im not too great with soldering have a bit of a hit and miss when it come s to it

An alternative might be a DIY kit I'm thinking about...

http://sudomod.com/forum/viewtopic.php? ... =90#p14746

[RxBrad]

Curious if this post will be updated to incorporate the diode for making use of the LBO pin on the PowerBoost. I get nervous trying to solder into that surface mount LED.

Also, does the updated LBO/diode setup use Popcorn's low battery detector, or do you have a new program cooked up?

[Camble]

@RxBrad Not to worry. The LBO interface is included. I had a bit of trouble with it, but tweaked @Popcorn's script so all is well.

You can modify the script yourself by disabling pull-up/down on the GPIO pin, but I'll stick up a modified version of the script on GitHub so no programming required.

[edit] Sorry, I thought we were in the pre-order thread. It's technically a different problem, but I could have a quick look at including this in the guide. In the meantime, you might want to source yourself a diode. and a 500k resistor.

[Artist_block]

Do you have a link for the Github? I couldn't find it.

[RxBrad]

Sorry, I thought we were in the pre-order thread. It's technically a different problem, but I could have a quick look at including this in the guide. In the meantime, you might want to source yourself a diode. and a 500k resistor.

I thought about squinting at the leads in this picture and trying to build it, but since there's no 500k resistor noted on the PCB, I'm guessing it's not the final version? This seems to show 100k to the FET and 33k to the diode.

(Also, I have 470k resistors... think this would work, or should I add another 30k ohms in series? 500k resistors look pretty hard to come by outside of the SMD versions. I can find 470k and 510k.)

[Mischief]

I assume when the new boards are ready there will be a new guide with the new script?

[Camble]

@Artist_block https://github.com/NullCorn/GBZ-Power-Monitor

@RxBrad The 33k resistor is nowhere near enough and was replaced with 500k. 470k or 510k should do the trick, it's really just that high to ensure the low battery LED doesn't light before the battery is low. 1M would also probably work.

@Mischief Yes. Probably.