Nand Unlock Error

anyone know why when I try to unlock the memory appears an error message below?

OMAP3 beagleboard.org # nand unlock
Usage:
nand - NAND sub-system

Alessandro

In recent versions of U-boot, I have not needed to use nand unlock, I
could just write using "nand write"

Brett

Thanks Brett,

I installed a 2.6.28 Angstrom version in mey BB. But in login screen, my
USB devices (mouse, keyboard) don´t works. Have a any way for create a
new account by serial terminal in beagleboard login?

As my usb devices don´t works, I can´t sucess for creat a new account in
first time.

Alessandro

Brett Kuehner escreveu:

Do you have a shell prompt on the serial terminal? If so, you can
probably use "adduser" to create a new account, although I don't have
my beagleboard handy to try that out.

Do you know why your keyboard and mouse aren't working? Some common
issues involve powered USB hubs (you should definitely be using a
powered hub), and possibly the USB cable from the beagleboard not
being the right type. It needs to have two pins on it connected so
that the beagleboard switches the USB port to "host" mode rather than
"device" mode. The beagleboard web site has more info about these
requirements.

Brett

The mouse and keybord is working in 2.6.27 version, but in the 2.6.28
are still not working.

Someone had the some problem?

Alessandro

Brett Kuehner escreveu:

Hi all,

Something thats does not have to believe.... I only reinstall everything again and turn on. Now it´s all run.

tks.

Alessandro

Alessandro Corrêa Mendes escreveu:

This is a slightly oddball question, but: when polarised light reflects off a surface (lets say a regular wall or an overhead projector screen) is the reflection still polarised? Why do I ask… well…

Ingredients:
2BB + 2PP + SGX = 3d projector
Lots of SGX rendering
Polarising filters
3D glasses
Just a dash of power (circa 10 watts)

Method:
Take a beagleboard with an attached pico projector
Take another beagleboard with another pico projector
Connect the OTG port of one BB into the EHCI of the other (for synchronisation)
Place polarising filter (horizontally infront of one projector)
Place polarising filter (vertically infront of the other projector)
Aim both projectors and use calibration image to make sure images are aligned properly
Install some cool SGX rendering software.
Put on polarising 3D glasses.

Result:
SGX rendered 3D images… displayed… IN 3D…!!

Does someone want to tell me if this is even feasible before I lash out $700 on two pico projectors…???

Mike

Michael Evans <horse_dung@hotmail.com> writes:

This is a slightly oddball question, but: when polarised light
reflects off a surface (lets say a regular wall or an overhead
projector screen) is the reflection still polarised? Why do I
ask... well...

Ingredients:
2BB + 2PP + SGX = 3d projector
Lots of SGX rendering
Polarising filters
3D glasses
Just a dash of power (circa 10 watts)

[...]

Result:
SGX rendered 3D images... displayed... IN 3D...!!

I have seen such a demo done with what looked like a normal surface
and polarised glasses, and the result was impressive. There may have
been something more to it than met the eye though, so don't take my
word as final.

Hi, I asked a friend of mine, he does some investigation in optics.

He says that the reflection will be polarized, but the polarization may be different, depending on the angle of reflection and on the surface.

Also that is similar to the traditional red and blue glasses, but with polarization the colors remain the same and you don’t see those greens and reds.

And a main problem. The images been projected should be taken from two different point of views as if each point is a different eye.

Finally, he recommends this page for a better understanding.
http://science.howstuffworks.com/3-d-glasses2.htm

Hope this helps, sounds like a very interesting project!

BR,
Ernesto

2009/5/28 Måns Rullgård <mans@mansr.com>

I'm pretty sure that some surfaces will randomize the light so it is no longer polarized. You may be able to find particular screens that preserve polarization during reflection, but I wouldn't count on it for any screen or wall that isn't specially selected to do so.
My thinking is that since some surfaces act to polarize light (like asphalt, noticeable if you rotate your head on a sunny day while wearing polarized sunglasses and looking at a smooth road), other surfaces will "depolarize" it.
See: http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/light/u12l1e.html#refln

Also, this wikipedia article says that only particular types of screen are suitable for 3D projection:
http://en.wikipedia.org/wiki/Silver_screen

Brett

Michael Evans wrote:

This is a slightly oddball question, but: when polarised light reflects
off a surface (lets say a regular wall or an overhead projector screen)
is the reflection still polarised? Why do I ask... well...

Ingredients:
2BB + 2PP + SGX = 3d projector
Lots of SGX rendering
Polarising filters
3D glasses
Just a dash of power (circa 10 watts)

Yes, that's what people have been doing with slides for ages, they just have/had
the advantage that a 250-500W slide projectors has a wee bit more light to play with
than your picos. Your polarizing filters will eat up a lot of light, so I am not
sure how much will be left to hit the screen (which has to preserve polarization,
so it cannot be a "high gain" one I guess) But I guess you can test a polarizer
with one pico to see for yourself.

You would need a screen that preserves polarization. A normal wall or OHP screen would scatter too much to be usable.
Try with a silver lenticular screen.

Good luck. Sounds like a great project.