USB Hub or/and USB and Ethernet gets a white screen

Hello,
I have a mini6410. Installed qtopia with the 7" lcd.
I pluged in a USB keyboard and all works well. If I pluged in the ethernet
and the USB keyboard, in that moment the networks come up I get the white
screen. (the led-player works fine after that). If I connect an USB hab
(2.0) and the keyboard in the hub, I had also the white screen. I testet it
white the zImage_a70 and zImage_s70. Both the same. (It's right that the
s70 is for the 800x480 lcd and the z70 for the vga?)
I testet the connector from the lcd and repluged it several times. No
changes.
Is it a problem to use a 2.0 USB hub? Or must it be an 1.1?

I only have a 4.5V power supply at the moment. Could be this the problem?
And why gets the screen white? Is that the mini-version of the
"bluescreen"? :-)

Any other tips? 

At the moment the mini is useless for me:-( I had to use the ethernet and
an USB hub for serious working!

Thanks and greetings from Germany :-)

Not sure about the mini6410 but if the mini2440 supply drops below 4.7Volts
it dies.

What happened to the supply that came with the mini6410?

Me again.... made some tests with different USB hardware.

The board is up and running in the normal way. I running the clock
application from qtopia. 
I plugged of the keyboard and plugged in again. Several times nothing
happens.
The same with an USB mouse. Works fine. Plugged of and in, works fine
again.
A "Fritz wlan stick", nothing happend.
A bluetooth stick, nothing happend.
Active USB hub, the board freezes. The lcd becomes withen several seconds
white, the pointer or the clock application hangs. Must restart the board
after plug of the hub. If I leave the hub plugged in, there is the boot
logo some seconds and then the lcd becomes white.
The same with an passive hub.
A gps mouse plugged in, nothing happens.
A wacom tablet, nothing happens.
A creative webcam, the board freezes.
An usb cardreader, nothing happens.
A scanner:-) Nothing happens.
A Qualcomm 3G stick, the board freezes (f**k, I want use this stick with
the Mini:-( )


A don't have more usb devices for testing:-)

Why freezes the board with some devices and not with the other? Why don't
work the hub? Is essential for me to have an usb hub. I need the gps, 3g, a
switching-board (is that the word in english? :-) Turn 8 switches on or off
by a board conected by usb) and an usb rfid reader working on the board
(and maybe an usb fm radio:-) ). Controlled by a java (swing) touch Ui:-) 

And for development the ethernet.

But at the moment ethernet and usb doesn't work together and no usb hub is
working:-(

Hope someone can help me solve the problem.

Greetings

Holger

Great about all the details, but how about an answer to my question?

Also, grab a digital multimeter and monitor your power voltage as you plug
these various devices in.

It came without a supply. I bought it at www.watterott.com. 
Where to get the voltage?

On the downloads page is says that it uses a 5V regulated power supply.

You said near the top of this thread you were using a 4.5V supply.  I
assumed you either measured it or was confident that it was 4.5Volts.

One gains confidence by actually measuring the voltage unloaded and under
load with a reliable digital multimeter.

You measure the unloaded voltage by placing the positive lead of the
multimeter up the centre of the DC power plug and the negative lead to the
outside sleeve of the DC power plug.

You measure the loaded or running voltage by connecting the negative lead
of the digital multimeter to a convenient ground, ie the touchscreen
pillars and the positive lead to one on the pcb connections to either the
DC power socket or one of the power switch contacts.

Then while measuring this voltage try plugging in all your devices and tell
me how much the voltage drops by.

Ok, now I have another power sppply. I measured 5.15V if the Mini is of. If
is on there are onlu 4.45V !! The lcd doesn't work. It's from switching on
white. The first few seconds I can see light colored lines "behind" the
white, then it switches to white at all. The led-player works fine, so the
mini should run. I will connect the serial cable to see if the mini says
something to the console, but I think I have to less voltage:-(
On the power supply is writen 5V 800mA, exact the specification from the
hardware datasheet of the mini.
But I think the reason is the power, because with the other supply it
worked "better":-) It worked so long the usb device pluged in. I thing this
devices that freezes the mini needs to much power????

Now I am back to the 4.5Volts power supply to make some tests:
The mini is up and running (idle): 4.59V
The Ads Demo running: 4.54V
usb keyboard: 4.59V
running dmesg at the terminal on the mini: 4.54V
Connecting network cable and mini is idle: 4.54V
Ping www.google.de: 4.51V on each ping
Ping from other machine to the mini: No changes. Idle at 4.54V (keyboard
also pluged in)
up to now, I leave the pc pinging the mini to see if is running.

Now I plug of the keyboard and test the different usb devices (see first
posting)
Mouse: Screen freezes white, 4.62V. Ping works.
Restart with connected networkcable, bootscreen (penguin) ok, then screen
gets white, ping work! No usb device connected. Tried several times. While
screen is not white, the voltage is 4.54 and if screen becomes white, it is
4.62V. After a few seconds, the backlight turns of and the voltage is 4.81.
If I touch the screen, the backlight turns on and the screen is only white.
Ping works over and over. So, mini is working, but the UI is failed????
Booting with disconnected networkcable works. When the mini is running I
can plug in the network cable and ping suddenly works.
Tried the mouse again, it worked. 4.53 V

Bluetooth stick: 4.55V no freeze, mini is running
Fritz Wlan stich: 4.51V mini running a few seconds then lcd becomes white,
. After a few seconds backlight turns off, voltage raises to 4.79V. If I
touch the screen, backlight turns on again until it turns of a few seconds
later (seems a timeout). Ping is running, led-player is running.
GPS mouse: without network cable pluged in needs 0.02V. With connected
network cable the screen gets immediately with. Tried several times, every
time the same behavior.

3G Stick: Voltage shortly to 4.42V and mini freezes slowly until lcd is
white.

Remember: Idle white network cable: 4.55V

usb hub (passive): shorty 4.53V and mini freezes slowly, network don't work
any more

Selfpowerd usb hub: mini becomes immediately white, no decrease in voltage,
ping doesn't work anymore.

USB Card reader: 4.51V mini becomes white, ping working, backlight turns
off a few second and if I touch the screen backlight turns on again, no UI
but mini seems to working (network, led-player).

So, what tell me this all? To less power? :-)
But why do the mini not booting with pluged in network cable but network is
working if the mini is running and then the cable was plugged in?

Why does the self powered hub not work? It does not need power from the
mini.

Why does the mini not work with a 5V (5.15V measured),800mA power supply,
and not with a 5V, 1A supply?

Is there a hardware problem with my mini? Or is this a software problem?
I would try to install an other OS. 

Thank for you interesst:-)

Greetings
Holger

With Windwos CE the mini voltage is 4.61V. Everytime I clicked on the
system icon (the icon on the bottom in startmenu) the system freezes
slowly. So I am not able to switch from chineese to english:-(
I painted little in paint, then paint hangs. Could not close. Startmenu
works. If I click on system icon, mini freezes again and lcd becomes white.
Windows CE does not work!

Ubuntu installs successful. Two beeps and all LEDs are round-robin
flashing. At booting there is only a blue screen. The 4 LEDs are dimmed on.
I think the mini hangs:-(
Android does not install. Will try again.

Well, you have done a lot of testing.  I just downloaded the mini6410
schematic.  Similar to the mini2440 the LCD runs off the "5V" supply.

Perhaps the operating voltage limits for the touchscreen controller are
more constrained than the rest of the unit.  The highest voltage going to
the rest of the unit is 3V3 (VDD_IO) and if that is a LDO regulator
everything except the touchscreen will probably work down to 4Volts or
thereabouts.

Looking at the touchscreen schematic lcd-a70 I see a separate 3V3
regulator, feed off the "5V" supply, that supplies the actual touchscreen
controller.

Two issues: 
- what are the drop-out voltages of these two regulators so that you can
determine which goes out of regulation first.
- how much the "5V" (VDD_5V) can drop on the actual touchscreen controller
before it loses it's marbles.

Suspect that this last issue is the most important.

***
So, what tell me this all? To less power? :-)
But why do the mini not booting with pluged in network cable but network is
working if the mini is running and then the cable was plugged in?
***
Maybe, it draws more current starting it up this way??

***
Why does the self powered hub not work? It does not need power from the
mini.
***
Good question.  Are you sure it doesn't draw any power?

***
Why does the mini not work with a 5V (5.15V measured),800mA power supply,
and not with a 5V, 1A supply?
***
Maybe, because the loaded voltages are different. I think you didn't want
the second "not" in that sentence.

I would put a lab bench supply on the whole unit and starting at 5.0V
slowly decrease the voltage until various things start to go wrong.  Then
separate out the connection to LCD controller and leaving the rest of the
unit at 5.0V repeat the exercise.  I appreciate you may NOT like hacking
about on the board.

How about comparing notes with someone else or test a second unit?

I would also look at the ripple on these two supplies with an oscilloscope,
as they are loaded up.

Hi,
thanks for your help.
I think I have solved it!!!

In the moment it runs with Android but I think it would do the same with
Linux.

Yes, the problem was the power supply. The power supplies I used are ... hm
... toys!!! So, the joke is over and I connected the mini to my pc. This
has an 800W power supply. 5.01V at the connector for the harddisk. Nothing
connected to the mini I have 4.98V. At the moment there is the passive usb
hub connected, the 3G Stick (working, dmesg recognizes it and the leds in
the stick are flashing), the gps mouse (alse working), the wlan Stick
(working, led is flashing) and the bluetooth stick. All at the same time.
(It,s only a 4-port hub:-) ). The voltage now is 4.92V. The mini is running
without problems. And network is also working.
So, the good thing of the last few days is, that I know how important a
good and stabile power supply is.

Greetings from Germany

Holger

That is good news for you, but we still don't know where the critical bit
of circuitry is.

Do you have the 5V on your computer come out the back panel?

My case of the computer is never closed:-) A very large cooler for the quad
core (I had often problems with the boxed cooler, with the new cooler they
are gone. But the case cannot be closed:-) )
And connected the mini with a selfmade cable:-) Direct from the harddisk
power connector from the power supply.

Now, you will need to come up with a solution if you ever want to use the
mini6410 stand-alone.

I have been working with hardware for 40+ years, but not brave enough to
use my computer power supply as a general purpose bench supply :)

The mini6410 should work in a car as onboard copmuter in a carsharing car.
The goal is that the mini is always on with a extra battery in the car.

The PSU that normally ships with the FriendlyARM boards is 5V 2A. Yours was
seriously under rated for a 7" system. Watterott probably doesn't use them
because they are not CE or RoHS. In the U.S. we can still use real solder.

The critical circuitry is 3.3v needed by Innolux display:
- LM1117-33 on lcd board is cheap and needs at least 1.2v dropout voltage
- ZIF connectors on lcd board and cpu board - depending on luck and
brightness, the voltage drops between 0.1 to 0.5v

According to Innolux manual - it needs at least 3.1v to work correctly.
It means - with bad luck with connecting lcd cable - LCD goes white even
when power supply gives 4.8V.