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Topic: U8glib: Graphics Lib for LCDs and OLEDs (Read 61697 times) previous topic - next topic

olikraus

#60
Jul 22, 2012, 07:43 am Last Edit: Jul 22, 2012, 08:00 am by olikraus Reason: 1
Good work.
I changed line 79 to 0x004, line 61 to 0x008 and added the constructor U8GLIB_NHD_C12864 to all examples.
The orientation can be changed later by the group of rotation commands: http://code.google.com/p/u8glib/wiki/userreference#setRot90

Quote
I'm making an Arduino shield for this LCD

Looking forward to read about your shield.  :)

I want to include issues 75, 79 and 81 into the next u8glib release. So i am not sure about the next release date at the moment, but everything is in the repository.

Thanks for all the testing and the pictures,
Oliver

Edit: I have also updated the reset functionality. So maybe this will also work now. Connecting the reset line to 3.3 is a little bit critical. It may work, but usually reset control by the controller or a RC circuit is better: http://code.google.com/p/dogm128/wiki/dogs102_arduino_hardware
For a shield i would suggest to add the RC circuit to have one more pin for the user.

charlespax

Thanks so much for your help, Oliver. I wouldn't expect my shield to be available until after December 2012, so no rush on a release.

I used the constructor as "U8GLIB_NHD_C12864 u8g(13, 11, 10, 9, 8);" and connected the LCD reset pin to Arduino pin 8. Works just fine, but I will use the circuit you mention.

olikraus


I'm using the library for the DFRobot ST7920 128 X 64 LCD and it works without a problem, both in serial as in parallel mode. But the weird thing is, is that the parallel mode is a bit slower. In SW serial I got a refresh rate of 6 to 7 frames per sec and in 8bit it goes down to 4 to 5.

Is this normal behavior or am I doing something wrong?


I have improved speed for the parallel mode by 30%. This fix will be available with the next regular release. Please send PM for a beta release including this fix.

Oliver

koyaanisqatsi

Hello,

I'm using u8glib for an LCD screen I pulled out of an old Dell LTO tape backup library.  It turned out to be a LC7981 chipset at 240x128.  I was able to modify the library files for the screen, based on some other mods I found already in the files and all is well. (U8GLIB_LC7981_240X128)

I have a question about fonts - I'd like to create my own font, both for a custom look and to save some memory by omitting characters I know I won't need.  Can you post some info for how to create/add custom fonts?  I've been looking at u8g_font_data.c and it looks like they're just a big bitmap with some parameters indicating the boundaries of each character, but I can't seem to get my head around the array structure.

It will soon be a super deluxe HVAC controller:


Thanks!
What about elevensies? Luncheon? Afternoon tea? Dinner? Supper?

olikraus

Hi

Nice work. Glad to see that u8glib is usefull for you.

The U8glib font format not only contains the bitmat data but also a lot of glyph information for precise font rendering (mainly used for my other lib m2tklib). Some information available in the fonts are described here: http://code.google.com/p/u8glib/wiki/tstring.
The U8glib font format also tries to crop the bitmap data to save as much ROM as possible. All the glyph metric calculation, the bitmap reduction and the font encoding is done by an external program: http://code.google.com/p/u8glib/source/browse/tools/font/bdf2u8g/bdf2u8g.c. Simply compile the c-file with a unix or windows c-compiler (or send me a PM if you need the executable).

bdf2u8g requires a font in the bdf format: http://en.wikipedia.org/wiki/Glyph_Bitmap_Distribution_Format

On the internet several fonts are available as bdf files, see for example here: http://cgit.freedesktop.org/xorg/font/

But it is also possible to convert truetype fonts (ttf) to bdf: I have used http://sofia.nmsu.edu/~mleisher/Software/otf2bdf/ and http://fontforge.org/. I am sure there are more tools (google has some 100.000 hits for "ttf bdf").

Oliver




koyaanisqatsi

Cool, thanks!  I'll see if I can get anywhere with this.  I have little knowledge of how fonts work, so this may be more than I have patience to do.  ;)

U8glib is a really nice library, BTW - pretty easy to use and modify.  I was a little intimidated at first, but dug into the files and figured out how to create a new constructor.  I have two other LCDs I've pulled out of old equipment that I'm going to try and get working.  One is a little  5 x 2 character out of a Dell server (it's the little status/diag LCD).  I haven't figured out what chip is on it yet.  The other came from a Quantum tape library and I believe is a ST7565 128 x 64 chip-on-glass type.  Both have ribbon cables so I need to get breakout boards to use them.

Anyway, thanks for your help and the LCD library!
What about elevensies? Luncheon? Afternoon tea? Dinner? Supper?

GeorgeG

Thank you Oliver for your wonderfull work!

I tested the DFRobot st7920 witch has an spi module attatched to take care of contrast etc. and it works fine in arduino environment.
I would like to use it in pure C but the constructor requires an A0 connection,while the arduino library does not.

How could i resolve  this?

Thanks again!

olikraus

Hi

The st7920 does not require an A0 line. Instead it has a very special low level protocol. Unfortunately i have not yet ported the Arduino version of the low level driver: http://code.google.com/p/u8glib/source/browse/csrc/u8g_com_arduino_st7920_spi.c

I have put this as  issue 85 on the u8glib issue list.

Thanks, Oliver

GeorgeG

Thanks for the reply..
Ill will use the arduino library then,no problem!

olikraus

#69
Aug 15, 2012, 12:57 pm Last Edit: Aug 15, 2012, 01:07 pm by olikraus Reason: 1
Hi

I have added support for the st7920 with avr to u8glib:

The test environment includes my NHD 192x32 display with ST7920 controller (upper right, the bright light from upper left makes the contrast a little bit weak). Lower left is an unused EA 132x32 display. Lower right the ATMEGA 328 with green power LED. Upper left the AVR programmer.

A beta release with support for st7920 for avr is avilable on request.

Oliver

olikraus

Hi

I have released version 1.08 of u8glib. The new release has been optimized for speed and includes support for some more OLED chips. See details here: http://code.google.com/p/u8glib/.

This release also has a new COM interface for I2C/TWI based displays. The first supported I2C display is the Seeedstudio 96x96 OLED.

Thanks to all testers of the beta releases!

Oliver




bperrybap

Oliver,
I've looked but can't seem to locate any information on the bitmap pixel format.
i.e. things like is it LSB to MSB, 8 bit vs 16 bit, vertical vs horizontal encoding etc...
Is it universal in that it works on any glcd or is the bitmap format just a raw image
for the given glcd so each glcd has a different pixel format?
Have I missed this somewhere?

--- bill

olikraus

Hi Bill

The drawBitmap procedure expects a byte array, which is printed from left to right, MSB on the left. The drawXBM also expects a fixed format, but i can't remember the bit orientation.

The fact that each display might have a different byte orientations forces U8glib to perform a bitmap translation step from the high level command to the native display byte orientation. Indeed this is one of the most time consuming steps in U8glib. Unfortunately i do not know how to avoid this. There is not common memory layout for the displays. Each chip has an individual memory setup. Everytime I add a new chip, I am surprised to see another new memory layout  :smiley-roll:

Because i anyway had to add such a bitmap translation, it was not a big task to add the 90 degree rotation for the display orientation. Indeed this is something what i got almost for free (with respect to computation time): I just had to exchange the bitmap translation procedures, when such a different display orientation is requested.

For one of the newly added OLEDs I had to implement a completly new memory layout:
- I noticed that the new memory layout reduces speed (of course only for this display)
- So i decided to work on an overall speed optimization.
- All of the u8glib code was ported to my desktop so that i can apply "gprof" to it.
- I did a lot of gprof tests with the code to identify those procedures where most of the computation time is lost
- This all lead to several improvements, including one, where i had to restructure parts of the high level/low
level communication.
- Depending on the high level comands, speed is now improved by up to 30%, but still, GLCD is much faster.
- After spending many many hours on speed and performance analysis this summer, i know that there is not much room for further improvements.

U8glib offers flexibility and trades this for speed.

The good news is, that u8glib still is faster than many existing libraries (except GLCD).   ;)

Oliver

andrew-d

#73
Oct 21, 2012, 05:52 am Last Edit: Oct 21, 2012, 07:44 am by andrew-d Reason: 1
First off the U8glib is fantastic. I've used it successfully with several displays. For me with my limited programming skills this library just lets me use displays and get on with my projects. Thank you Oliver.

On to my problem, I have a new LCD module with a UC1701 controller in it that I'm struggling to make work properly with U8glib. Looking at the "Supported Devices" table it's not supported, but from my testing it almost is because it uses a UC1701 controller. Here's what little I know about it:

Quote

Labelled: "Open Jumper, 12864"
Size: 47 x 38 x 4mm
Supply Voltage: VCC 4.5 to  5.5V (built-in booster circuit, no negative voltage required)
Controller: UC1701, Based on: 12864
Display: 128x64
Interface: SPI


Deal Extreme link to product I purchased.
http://dx.com/p/mini12864-blue-backlight-dots-graphic-lcd-display-module-red-153821?Utm_rid=90992748&Utm_source=affiliate"

I'm using Ardunio v1.0.1 IDE, Arduino Uno R3 and U8glib v1.08 with the U8gLogo example sketch, I've added two lines:
Code: [Select]

u8g.setContrast(0);  // in the setup
u8g.drawFrame(0, 0, 127, 63); // in the picture loop, helps determine screen edges / locations


Here's what I've tried:

U8GLIB_DOGS102 u8g(13, 11, 10, 9);                    // expects 102x64 display mine is 128x64

  • Image is about 5 pixels to the left, the right edge has random garbage pixels as expected due to 102 vs. 128 pixel width

  • As listed in the "Supported Devices" table no contrast adjustment, screen is barely visible almost impossible to photograph



U8GLIB_DOGM128 u8g(13, 11, 10, 9);

  • Again as listed in the "Supported Devices" table no contrast adjustment, screen is barely visible almost impossible to photograph

  • Image is again about 5 pixels to the left and the right edge has random garbage pixels

  • This is the closest I got the display to working




U8GLIB_DOGM132 u8g(13, 11, 10, 9);  // expects 132x32 display some errors expected

  • Contrast works without fault (0 seems to be the best value for my display), "Supported Devices" table might need updating

  • Image is again about 5 pixels to the left but this time the right edge has no garbage pixels (perhaps something is cleared?)

  • Only the top half of the image is drawn, as expected due to 32 vs. 64 pixel height



Note: I had to power cycle the display between testing as it seems to retain the display memory from previous programs.

Here's some photos of the display using U8GLIB_DOGM132:
http://www.flickr.com/photos/andrew-d/8107440762/in/photostream

Would it be possible to support this device? I'm happy to perform any testing and provide photos for galleries (I'm a better photographer than programmer).

Corrections to version numbers made.

olikraus

Hi

I am always happy to support new displays with u8glib.

This is my usual procedure for adding new devices:
1. Select a u8glib device which almost works
2. Rename this device to the new display
3. Fix display problems (garbage, display shift etc)
4  Fix contrast issues

What is your impression? Which u8glib device would be a good starting point for the "Mini12864"?

One of your pics shows a perfect u8glogo: http://www.flickr.com/photos/andrew-d/8089943789/in/photostream/
But you did not mention the u8glib device.

Additionally i wonder about the version number v12.
Official download is here: http://code.google.com/p/u8glib/downloads/list
Latest version of u8glib is 1.08

All in all, there are good pictures and existing u8glib devices mostly work, so it should not be a big problem
to fix issues with your display.

Oliver


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