Mausberry Shutdown Circuit power drain issue

[RyanFromQA]

I’m in the middle of a RetroPie-in-SNES build, and I’m trying to use a Mausberry shutdown circuit for power switching. I got it functioning for power just fine, but it seems to be causing either a voltage drop or its limiting current. I have an email in to Mausberry but I haven’t heard back yet, and I thought someone on here might know something else to try.

A bit about my setup:

• Pi 2
• RetroPie 3.0
• MausBerry Bring Your Own Switch shutdown board
• Apple 10W iPad Adapter

Typically I have plugged in:

• USB Keyboard
• Logitech USB Dual Shock
• Ethernet
• HDMI

Without the shutdown circuit, I am able to run the Pi on the 10W adapter, and even a 5W iPhone adapter with no low-power indicators. However, with the shutdown circuit and all those things connected, I get a constant low-power warning from the Pi.

Here are the troubleshooting steps I have tried:

1. Removing LED from shutdown circuit (this took the warning from constant bold to sometimes-fading-but-returning).
2. Unplugging Ethernet (this took the warning from almost-constant to intermittent, usually when the system is under load)
3. Unplugging keyboard (this didn’t seem to have an effect)
4. Swapping USB cables (this didn’t have an effect)
5. Swapping power supply for another Apple 10W power supply (also no effect)
6. Using a powered usb hub with a 2A power supply to power the system (went back to constant power warning)
7. Using a USB port on my macbook pro which can charge an iPad Air to power the system (constant power warning)

What should I try next?

[Anonymous]

I just finished a build using all the same components you’ve listed and it seems to be working fine for me. A problem I ran had was in my initial set up; I had the Mausberry Pi’s GPIO pins in the wrong locations on the Pi’s GPIO board. Perhaps you’ve done the same and have connected the circuit’s pins to a constant 5V or ground pin? The pinout shown on Mausberry Circuit’s setup page is not for a Pi 2, which tripped me up a little. Simple mistake to make but easy to do, so I fixed it with the correct pinout found here:
https://www.raspberrypi.org/documentation/usage/gpio-plus-and-raspi2/

Just the first possibility to come to mind, hopefully your problem is as simple to fix as this.

[RyanFromQA]

Yeah, I did that initially too. Being a noob, I mistook GPIO 23 for PIN 23. I have the board connected to the right pins, and it functions to shut down the pi just fine. Very strange, perhaps I got a bad board.

[grizzlema]

I too am having this problem. I have the following equipment:

Rpi2
Wifi Dongle
Bluetooth Dongle
keyboard adapter
the USB Mausberry circuits shutdown circuit
inside an old NES case with the LED attached to the 5V and ground gpio cabcles
Powered from a 2A phone charger

When powered through the shutdown circuit i get a fading in and out low power indication, but when plugged directly into the Pi i receive no low power indication.

I first started with the Belkin 4 port ultra slime USB Hub, but i got a constant low power, so i decided to not even use it.

I purchased a 3A micro usb charger to try out and am waiting for it to get here.

Is it possible that the shutdown switch is adding to much resistance and cutting the power down too much before it reaches the Pi?

[RyanFromQA]

Just got a reply from Mausberry, he thinks it’s likely the USB cable I’m using, but he was kind enough to send me another one just in case. I asked him to send the direct-plug variant this time, eliminating one usb cable link in the chain. I probably should have ordered that one all along.

I’d be interested to know how it goes with the 30w power supply though, grizzlema.

[grizzlema]

Ill let you know if it works out. let me know if the direct one is any better. if it works out i might get one. i just dont feel like redoing the switch again.

[grizzlema]

So I tried my 3A micro usb charger with the USB version of the shutdown circuit and still get a low power indication.

[RyanFromQA]

[quote=105990]So I tried my 3A micro usb charger with the USB version of the shutdown circuit and still get a low power indication.

[/quote]

Okay at least that’s one thing ruled out.

I haven’t gotten the replacement circuit yet but I was making an order at Monoprice so I threw in a couple of these, which have thicker power wires. We’ll see if they help.

Edit: forgot the link
http://www.monoprice.com/mobile/Product/Details/5456?mainCategoryId=103&categoryId=10303&subCategoryId=1030307&cpnCd=

[grizzlema]

Ive been using my extra samsung cables and they work fine directly plugging into the pi with a 2A adapter. I think it has to do something with the ciruit itself.

[RyanFromQA]

[quote=106064]Ive been using my extra samsung cables and they work fine directly plugging into the pi with a 2A adapter. I think it has to do something with the ciruit itself.

[/quote]

Well oddly enough, the USB cables seem to have worked! I hooked it up briefly last night with them, and I saw a brief warning square while it was first booting up, but never again after that. This was with the keyboard and ethernet plugged in I put it through it’s paces a little bit and never saw the warning, even faintly.

This weekend I’m going to reattach the LED and see if that causes enough of a voltage drop to trigger the warning.

I haven’t gotten the replacement board yet, but for now I’m satisfied.

[Author]

Posts