I put the SD card in the sd slot and tried to boot by pressing the S2 button while I connect the beaglebone black element 14 board to the usb for power the four led's began to flash but the image won't display on the screen.
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when i turn on the computer, the image on the monitor is completely black. When I plugged the Xbox into the monitor, there was a picture. Can somebody help me?
How can we flash a new image on a beaglebone black rev c via. USB without using sdcard ?
Try https://github.com/ungureanuvladvictor/BBBlfs.
This is a tool designed to utilize the USB booting mode of the AM335x series of processors.
When using the iPhone camera app for the rear facing camera, the video mode torch option enables the True Tone LED, switching on all 4 LEDs (2 "white", 2 warmer).
However when accessing the camera in video mode through AVCaptureDevice, the torchMode options are only "on | off | auto" and neither enables the additional 2 warmer LEDs.
Is there a hidden function that enables this?
Generally, how are features like this usually enabled for the stock apps, and not for others? Is it a case of hidden functions in the api, that are possible to find? or something more low-level?
In addition to the torchMode on/off there is also setTorchLevel with a value from 0 to 1.0. I have tested this on several models of the iPhone. To do this I have created a simple app to play with the TorchLevel value. Here are the results.
Using the built in iPhone flashlight
iPhone 6s white LED only (one LED)
iPhone 8 white LEDs only (two LEDs)
iPhone 10S white LEDs only (two LEDs)
iPhone SE2 white LEDs only (two LEDs)
All phones use only white LEDs through four levels of brightness in the built in flashlight app.
Using the built in Camera App
iPhone 6s - iOS 13.7
white and yellow LEDs when flash turned from OFF to ON in video mode
white and yellow LEDs when flash is turned from AUTO to ON in video mode
white LED only when flash is left ON in video mode but you switch to photo mode and back to video mode
iPhone 8 - iOS 13.7
white and yellow LEDs on when flash turned on (AUTO) in video mode in a dark environment
iPhone SE - iOS 13.7 and iPhone 10S - iOS 14.0
white and yellow LEDs on when flash is turned on (AUTO) AND recording in a dark environment
All phones tend to use both the white and yellow LEDs while recording video except the iPhone 6s can be “tricked” into using just the white LED.
Using setTorchLevel = 0.0 through 1.0
iPhone 6s - iOS 13.7
Brightness transition levels with White LED only - yellow LED off:
0.0 OFF
0.005 1
0.5 2
0.835 3
0.995 4
1.000 5 - Full Brightness
The iPhone 6s only lights up the White LED when using setTorchLevel to adjust the camera LED brightness.
iPhone 8 - iOS 13.7, iPhone SE - iOS 13.7, iPhone 10S - iOS 14.0
On the newer phones normally both the White and Yellow LEDs are active when setting the TorchLevel but you can "trick" the phones to get mainly the White LEDs active.
Brightness transition levels when White and Yellow LEDs are active:
0.0 OFF
0.005 1
0.125 2
0.165 3
0.245 4
0.285 5
0.325 6
0.405 7
0.445 8
0.525 9
0.565 10
0.605 11
0.685 12
0.725 13
0.805 14
0.845 15
0.885 16
0.965 17
1.000 18 - Full Brightness
To turn off the yellow LEDs, use the photo app to take a flash picture in a dark environment. After that, setting torchLevel = 1.00 turns on White LEDs full power and yellow LEDs at < 1/2 power.
Reducing TorchLevel slowly from this point drops White LED brightness as in the above table and slowly extinguishes the Yellow LEDs
By 1/2 Power the Yellow LEDs are nearly out. Switching back to Full power yields White LEDs on full and yellow LEDs barely on.
As torch level is reduced the yellow LEDs remain at very low power and are fully extinguished at some levels (0.660, 0.330, 0.180, 0.100 and others).
Once the torch level is reduced to 0.090 the yellow LEDs “come alive” and their brightness tracks the White LED brightness over the full range of torch level until you take another flash picture with the camera app.
The following first image is taken from a Virtual Machine and second is taken from a real pc. Why don't I see the dragging image on the real PC?
Virtual Machine
Real PC
got a question about turning pixels off on a screen. I can make a black image and show it full screen on my pc. Yet the screen looks black but the pixels aren't off. You can see the difference between an off screen and a black screen.
I am wordering if it would be possible to turn these pixels off via a program or is the best you can do: make them black?
I am looking for the delphi code to turn off the right half of my computer screen?
hope its clear!
thx
You can't turn off individual pixels, or parts of the screen. Either the screen is on or it's off.
This works a bit differently depending on what kind of screen it is, but nowadays LCD screens is the most common kind. An LCD screen has a backlight behind an LCD display; the backlight is always on, and shine through the LCD display when the crystals are transparent. Pixels are made black by making the crystals non-transparent, however they still let a fraction of the back light through. To make pixels completely black you would have to turn the backlight off, and you can only to that for the entire screen.
If I get it right, you want to turn off the power from the half of your monitor, what is impossible. It would have to be supported by your graphic card as well as by your monitor driver.
Turning off pixels can only work on new all-lead displays, except if you are switching off the computer, when all systems (including the screen) are off.