Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - shuntcap

Pages: 1 ... 4 5 [6]
76
Gemini PDA - Hardware / Rear camera module image quality very poor
« on: July 04, 2018, 03:12:05 am »
Quote from: vader
Photo taken with Sailfish camera at 4:3 (2560x1920). It isn't quite as bad as the android camera I believe.

 [ Invalid Attachment ]

Macro images and images of close objects are not too bad, unless you're under low light conditions where it refuses to focus at any ISO over 400 (for me at least).  But anything else, particularly scenery, is stunningly bad.

77
Gemini PDA - Hardware / Rear camera module image quality very poor
« on: July 04, 2018, 03:06:04 am »
Quote from: Neophy
Quote from: shuntcap
Just for fun, I modified the kernel to disable the MediaTek hardware JPEG codec which forced Android to use its own software routines to encode the image data in JPEG format.

Could you please tell us how to build and install the Android kernel?

Have you built and installed a Linux kernel before?  There are instructions for building and installing a kernel suitable for Debian here: https://github.com/gemian/gemini-keyboard-a...rnelCompilation.  Building for Android is slightly different, requiring the aeon6797_6m_n_defconfig config file instead, plus some extra Android-specific parameters sent to mkbootimg.  The keyboard mapping under my test kernel is not entirely correct (ESC is neither ESC nor Power, for example).  Planet Computers did not compile in support for /proc/configs.gz in their stock Android kernel so I don't know what's missing (yet).  But I don't want to get to too far off topic in this camera thread.

The SP5509 camera module's driver is in drivers/misc/mediatek/imgsensor/src/mt6797/sp5509_main_mipi_raw/sp5509mainmipiraw_Sensor.c, for anyone interested.

78
Quote from: DonOregano
Another update for anyone in the same situation:

As I said before the PlanetCom tech support told me to try to flash from a Windows machine, using virtualbox since I have no access to a physical Windows box. They also said that reformatting was probably not needed, and if the Windows flash did not work that I would have to send in my device.

With very low expectations I set up a Windows 7 vm (using KVM/virt-manager) and attempted to flash. I only got more error messages...

Well, fuck it, I thought. Lets reformat (as per shuntcap's instructions), so on my Linux box I formatted and tried to flash. More error messages!! Something about bad XRAM or something like that. But as a very last attempt, I tried reflashing from the Windows machine, and lo and behold! It worked! The Gemini now booted into Linux!

However, I realized that I had forgotten to add the NVRAM to the Windows flash, so I tried another flash from Linux (where I had the NVRAM backup), and now it worked without a problem!

The moral of the story? The flash tool seems to be a very fickle beast...

Thanks for the help, everyone!

Glad that worked for you.  Yes, the flash tool is quite fickle.  If it weren't, we wouldn't be chatting here.

79
Gemini PDA - Hardware / Rear camera module image quality very poor
« on: July 02, 2018, 03:41:58 am »
Quote from: mitchelln
I don't expect standalone camera quality. But I do expect better than Fisher Price toy quality.

The front camera quality is pretty good. I'd expect the rear camera to be as least as good. I suspect it's the same module, so what gives?

The rear camera module is an SP5509 sensor from SuperPix in China.  This is an auto-focusing module.  The image quality is remarkably poor, lacking any real pixel detail and smudging everything together.  There are hazy color artifacts on the edges of sharp intensity differences, suggesting either a poor demosaicing algorithm or just that the sensor is too small to pick up much detail.  Just for fun, I modified the kernel to disable the MediaTek hardware JPEG codec which forced Android to use its own software routines to encode the image data in JPEG format.  The images showed no improvement whatsoever which puts the blame on the image sensor (or the driver, but I doubt it and the code isn't commented anyway).  I have a Samsung J3 with a 5MP rear camera which takes much clearer photos, but the sensor lens appears to be slightly larger.

If it helps any, the only way I could get the rear camera to focus in low light conditions was to force the ISO to 400 or less.

If my eyes aren't fooling me, the live preview image is clearer than the saved image!  And using OpenCamera does not improve the image.  However, the image quality is still superior to having no rear camera at all.

Here is the sales pitch for the SP5509: http://www.superpix.com.cn/en/xiazai/SP5509.pdf

I believe the front camera is an S5K5E2YA.  It is fixed-focus.

80
Quote from: DonOregano
Wow, that is even more tempting now... But I will hold off until I hear from support again.

But out of cursiosity, could you give some more details on exactly the steps you took? Just to avoid any ambiguity in case I don't get anything useful from support.

Quote from: shuntcap
I formatted the entire flash
Do you mean you selected the "Format" tab, and with the defaults selected (Auto format flash, Format while flash, and no validation) pressed Start?

Quote from: shuntcap
modified my scatter file to rewrite the NVRAM partition from my backup copy.
You changed the "nvram" partition (aka SYS20) to have "file_name: NVRAM0" and "is_downloaded: true"?

Quote from: shuntcap
Then I used the download only option to reflash the entire device (including NVRAM).
And used this scatter file (with the NVRAM0 file moved into the firmware directory, so that it could be found) with the "Download Only" option selected to download the firmware to the gemini?

Don, you are correct on all three counts; however, I agree that you should wait until you hear from Planet before trying.  This definitely unbricked my device, but I wasn't involved in the Gemini development process and I'm new to the MediaTek platform, so it's possible I've missed something someone else will find later.

81
I had the same problem and did exactly as you are contemplating.  I formatted the entire flash, then modified my scatter file to rewrite the NVRAM partition from my backup copy.  Then I used the download only option to reflash the entire device (including NVRAM).  Worked fine.  But I would be interested in hearing what Planet advises.

82
Software News / A call for new contributors for the GKA project
« on: February 02, 2018, 02:12:54 pm »
Quote from: Grench
I want a Linux mouse driver to use the Gemini's touchscreen panel as a touchpad that just happens to physically be on top of a screen.  At that point we can have appropriate desktop-like control over the mouse pointer on the device itself.

Yes, applications should be optimized to the keyboard wherever possible.  BUT - we don't have to give up completely on having control over the mouse pointer.

I used xf86-input-multitouch (http://bitmath.org/code/multitouch/) instead of the usual xf86-input-evdev driver for a project of mine, which was converting an LG F3Q qwerty smartphone to run pure armhf Linux, no Android required.  I use the touchscreen as a touchpad.  I can double-tap it for a left click, and I remapped the cap keys to operate as mouse buttons (including middle and right buttons).  This gives true traditional X mouse control, right down to pasting selected text with the middle mouse button, all on a tiny 4" smartphone.  I haven't backed the Gemini, but it should be possible to do the same on it.

Pages: 1 ... 4 5 [6]