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QDX Rev 3a - Raspbery Pi 4B Reboot Issue

 

While rebooting a Raspberry Pi 4B with a QDX Rev 3a attached the reboot stalls at a blank screen after the OS shuts down. The RPi will remain in this state until either the power is removed from the QDX or the QDX USB cable is unplugged. Have tried a couple different power supplies for the QDX as well as the RPi. The RPi reboots normally without the QDX attached. The QDX is setup for 9VDC.
 

Hey Jeff!?
Is your rpi set up to boot from USB?

Andrey

On Fri, Nov 18, 2022 at 1:29 PM Jeff Nonhof KD8THX <kd8thx@...> wrote:
While rebooting a Raspberry Pi 4B with a QDX Rev 3a attached the reboot stalls at a blank screen after the OS shuts down. The RPi will remain in this state until either the power is removed from the QDX or the QDX USB cable is unplugged. Have tried a couple different power supplies for the QDX as well as the RPi. The RPi reboots normally without the QDX attached. The QDX is setup for 9VDC.

 

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Odd. My Pi-400 using PiOS 64bit reboots fine with the QDX attached and on. I have the OS on a USB SSD drive so maybe that makes a difference?

73,
Cliff, AE5ZA

On Nov 18, 2022, at 15:30, Andrey (KK7EEV) <andrei.proskurin@...> wrote:

Hey Jeff!?
Is your rpi set up to boot from USB?

Andrey

On Fri, Nov 18, 2022 at 1:29 PM Jeff Nonhof KD8THX <kd8thx@...> wrote:
While rebooting a Raspberry Pi 4B with a QDX Rev 3a attached the reboot stalls at a blank screen after the OS shuts down. The RPi will remain in this state until either the power is removed from the QDX or the QDX USB cable is unplugged. Have tried a couple different power supplies for the QDX as well as the RPi. The RPi reboots normally without the QDX attached. The QDX is setup for 9VDC.



 

The RPi is booting from a new Samsung Pro Endurance SD card. Fresh OS install. Everything has been updated.
 

Rpi400 REQUIRES a 5.1V power source, otherwise it can hang or reboot.
It gets grouchy is not enough 5v internally.? Same for the Rpi4.

That problem if a std 5V wart is used tends to make its behaviour more
known if USB devices are used that draw power from the Rpi.


Allison
------------------
Post online only, please no email.
 

Have tried multiple power supplies with no difference in the behavior.
Have tried different USB cables.
Have tried rebooting with only the QDX attached.

The reboot sequence goes like this.
Select Reboot from menu or terminal.
OS shuts down and the screen goes blank.
RPi USB power shuts off. The RPi stays in this state until either the QDX power is removed or the QDX USB cable is unplugged from either device or RPi.
Unplug QDX USB cable.
RPi USB ports power up for about 50ms
RPi USB ports power off for about 50ms.
USB ports power up and stay on.
RPi then boots normally.

It is acting like the RPi is not receiving the power reset signal until the QDX is disconnected or powered off.
 

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There are configuration settings to allow the Pi to boot from USB if it sees a USB drive when it boots. I don’t remember the details off the top of my head, but you might want to explore whether or not those are enabled.?

73, Willie N1JBJ

On Nov 18, 2022, at 5:15 PM, Jeff Nonhof KD8THX <kd8thx@...> wrote:

?The RPi is booting from a new Samsung Pro Endurance SD card. Fresh OS install. Everything has been updated.

 

I use an RPi400 with its own power supply on the USB-C port. I like to try multiple OSes and I don't like a lot of tiny microSD cards.
Therefore, I decided to use an external SSD as the OS storage and use BerryBoot to load the various systems.
Electrically, it looks like an externally powered USB hub (USB3) is connected to USB3 of the RPi400.
I connect to this hub with devices that have a higher current consumption.
I power the USB3 hub from a 5V 3A power supply.
I don't have a QDX, but I recommend trying this route.
--
Gyula HA3HZ
 

On Sat, Nov 19, 2022 at 09:37 AM, HA3HZ wrote:
I use an RPi400 with its own power supply on the USB-C port. I like to try multiple OSes and I don't like a lot of tiny microSD cards.
Therefore, I decided to use an external SSD as the OS storage and use BerryBoot to load the various systems.
Electrically, it looks like an externally powered USB hub (USB3) is connected to USB3 of the RPi400.
I connect to this hub with devices that have a higher current consumption.
I power the USB3 hub from a 5V 3A power supply.
I don't have a QDX, but I recommend trying this route.
So use a USB hub between the QDX and the RPi that is externally powered.
?
--
Gyula HA3HZ
 

On 19/11/2022 08:47, HA3HZ wrote:
So use a USB hub between the QDX and the RPi that is externally powered.
I guess a hub might make a difference but no power is taken from the USB by the QDX.
Only the data lines are connected, not the 5 volts power.

73 Alan G4ZFQ
 

On 11/19/22 04:19, Alan G4ZFQ wrote:
On 19/11/2022 08:47, HA3HZ wrote:
So use a USB hub between the QDX and the RPi that is externally powered.
I guess a hub might make a difference but no power is taken from the USB by the QDX.
Only the data lines are connected, not the 5 volts power.
73 Alan G4ZFQ
I think the 400 has a beefier power supply.

--
Linux Home Automation Neil Cherry kd2zrq@...
Main site
My HA Blog
Author of: Linux Smart Homes For Dummies KD2ZRQ
 

The Rpi400 has what you plug into it.? USe a 5V 3A supply and it gets cranky.
Been there did that aggravated myself.

Bought a 5.1V supply problem solved unless I start pulling power (USB SSD)
and it gets the reboots again.? For mine the bench supply at 5.25V was solid
Interesting thing was the USB output was then 5V before that it was 4.95V
for my case while the processor gets unhappy.

It is discussed here:
https://hackaday.com/2019/07/16/exploring-the-raspberry-pi-4-usb-c-issue-in-depth/
?
A powered hub can help but if your RPi4 5V supply uses a long lead or is on the short side
then it may still be an issue.


--
Allison
------------------
Post online only, please no email.
 

Jeff Nonhof KD8THX

That is the actual symptom of power issues to the RPI-4 Reboots.
Try a power supply marked to provide at least 3A at 5.1V

Also the USB-C is apparently softa broken and powering via the?
5V pins works better but is frowned upon (and is blocked from
occurring on Rpi400).

Also if the Rpi-4 is old enough (circa 2019) it may need an updated
boot and eeprom code.

Allison
------------------
Post online only, please no email.
 

Ruled out power supply issues by powering the RPi from a lab power supply set @ 5.25 VDC. Still not rebooting with the same symptoms as before.

Building on the suggestions below to try a powered USB hub between the RPi and QDX.
Found that placing a non-external powered USB 2 or 3 hub between the RPi and QDX the RPi reboots normally. Investigating further discovered that during the RPi reboot process the RPi is waiting for the USB data lines to go inactive before issuing a CPU reset to continue the reboot process. Because the QDX USB bus is powered by it's own power supply the USB data lines remain active while the RPi tries to reboot preventing the RPi from rebooting. By placing a USB hub between the RPi and QDX when the RPi shuts down the USB bus the hub deactivates the data lines to the RPi and the reboot process continues normally. So the work around is to add a USB hub to the setup.

Does anyone know of a config setting for the RPi 4B that would allow the RPi to ignore the state of the USB bus during a reboot cycle?

Another possible solution would be to power the QDX 5VDC and 3.3VDC bus from the QDX USB connection. Then QDX USB data lines would go inactive when the RPi power cycles the USB bus.

Thank you for all the suggestions
 

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Wow, good catch, I'll have to remember that!

73, Willie N1JBJ

On Nov 19, 2022, at 11:36 AM, Jeff Nonhof KD8THX <kd8thx@...> wrote:

Investigating further discovered that during the RPi reboot process the RPi is waiting for the USB data lines to go inactive before issuing a CPU reset to continue the reboot process. Because the QDX USB bus is powered by it's own power supply the USB data lines remain active while the RPi tries to reboot preventing the RPi from rebooting. By placing a USB hub between the RPi and QDX when the RPi shuts down the USB bus the hub deactivates the data lines to the RPi and the reboot process continues normally. So the work around is to add a USB hub to the setup.

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