[Guide] Graceful shutdown switch without Pololu [RETIRED]

[fdeluxe]

Hi,

I have a problem:

when I use the switch my Pi reboots instead of shutting down

I got the Siliconix JFET

Here's my wiring:

wiring.PNG (9.54 KiB) Viewed 7743 times

Using the wiring shown in the first post my Pi shuts off immediately
Reversing Source and Drain works, but I'll get Kernel panic when the Pi tries to shutdown

The label on the backside of the JFET reads:

2N
5460
T8630

[Camble]

@fdeluxe Your diagram shows the gate as being connected to the EN pin, where it should be connected to GPIO22. The gate may be pin 3 on the JFET, but it's the one with the arrow on the symbol.

[fdeluxe]

@fdeluxe Your diagram shows the gate as being connected to the EN pin, where it should be connected to GPIO22. The gate may be pin 3 on the JFET, but it's the one with the arrow on the symbol.

Yup, I know that the gate is the one with the arrow. Sorry, my diagram is faulty. For my diagram just pretend that the arrow one is drain.

[Camble]

@fdeluxe Test it without the 100K resistor, then try it with the resistor between the Gate and Source.

[larsen2011]

Due to business trips I've not been catching up on all the topics over the last couple of months, but have all the components available since to build the graceful shutdown on my own.
Now I see that the low battery indication is a new functionality, also considered in the printed board.

As I understand the first post, I can put the additional circuit somewhere, as it does not directly interact with the switch or the FET, correct?

One more question: the reset button can directly be installed between the EN and GND lines of the graceful shutdown board, correct?

[Camble]

As I understand the first post, I can put the additional circuit somewhere, as it does not directly interact with the switch or the FET, correct?

One more question: the reset button can directly be installed between the EN and GND lines of the graceful shutdown board, correct?

You are correct on both counts. The Raspberry Pi also has pins marked "Run" which can be used for your reset button. If you use these pins instead, all your other components will remain powered when you press reset.

[Ganreizu]

@camble

I got a metric ass ton of wiring and whatnot done these past few days. Fully wired up the shutdown pcb today and it works great! I noticed that when the battery is plugged into the powerboost and it is charging through the micro usb, it doesn't safely shut down (and similarly when the battery is unplugged and the system is powered by the micro usb). When the battery is the only power source it works like it should though. Have I done something wrong or does the graceful shutdown just not trigger for those cases?

PS: When i was setting up the script I noticed that rasppi's default keyboard is for the UK and had trouble finding "~" for a good half hour lol. May want to mention changing the keyboard default to people's "normal" layout in the guide.

[SidSilver]

I noticed that when the battery is plugged into the powerboost and it is charging through the micro usb, it doesn't safely shut down (and similarly when the battery is unplugged and the system is powered by the micro usb). When the battery is the only power source it works like it should though. Have I done something wrong or does the graceful shutdown just not trigger for those cases?

You may have done something wrong because it works even with usb plugged in.

[ReFl3x0r]

@Camble

I run into a kernel panic, when shutdown is initiated by low battery, because your script uses "shutdown -h now" and with the modification in the /boot/config.txt it's waiting for a GPIO-Powerdown.

Instead of using "shutdown -h now" couldn't we just overwrite GPIO27 to initiate shutdown? Would be more clean from my point of view.

[Camble]

@Ganreizu Glad to hear it! I'm not sure how you'd find the tilde on a US keyboard if the layout is UK to be honest. I know the tilde is beside the "1" for you, but it's beside Enter for me, along with # (our pound is £, on the 3 in place of # funnily enough)

It should shutdown regardless of power source, so as @SidSilver has said you may have missed something. I can take a look to confirm if you post some pics.