Raspberry Pi Forums

kulminaator

rew wrote:If you want you can buy: i2c_servo or spi_servo.

Well ... it's a bit too late to change my mind right now, but i will keep these in mind for any next attempts for sure, they look as if they can save a bunch of time

Nice products (and a nice price too).

kulminaator

answering to my own question here with a link: http://blog.stevemarple.co.uk/2012/07/a ... using.html ... looks like someone has done it a long while ago already.

kulminaator

I'm wondering if i'm missing out here on something ... but assuming that i already have the atmega chip assembled to another board (and having the spi connector there), can't i just use the spi connections from the rpi's own gpio port and skip the whole gertboard ? (i don't have one and i don't real...

kulminaator

Another robot building attempt here. My plan: building a snake from 8 servos (snake built from 9 sections, 8 servos to turn them (4 servos can turn the next part left or right and 4 servos can turn the next part up or down, the different turning directions would be interleaved for flexibility)). Cur...

kulminaator

spot on Voidious ... ajstarks library is nice for prototyping, but for speed you need a different approach (ps. if you can, unhook/make abstract the bcm/rpi specifics as much as you can in your code, so the developers on other arm implementations could reuse and recompile your code to run on theirs ...

kulminaator

Also running mrengman's compiled module 8192cu here for my Trendnet TEW-648UBM $lsusb Bus 001 Device 004: ID 20f4:648b TRENDnet TEW-648UBM 802.11n 150Mbps Micro Wireless N Adapter [Realtek RTL8188CUS] $lsmod 8192cu NB! The built in kernel module "rtl8192cu" that shipped with raspbian seriously just ...

kulminaator

True, I skipped SDL, because as it currently stands (as you noted), at least out of stock, it's not hardware accelerated on raspberry pi, hence making it a poor option on a 700mhz armv6 cpu. If we could get decent hardware acceleration for it, it would definitely become a good option, as it has nice...

kulminaator

While slightly offtopic and hacky suggestion ... abirrajkhowa , can't you render your results as the opengl pixel array on the framebuffer and read the pixels back from there (with ReadPixels callback) ?

kulminaator

I quickly ran head in first into OpenVG documentation, borrowed some code from mesa demos and ajstarks in another openvg thread. The code isn't horribly elegant yet, but should give some ideas to people who feel hopelessly lost. I promise i will clean it up at some point. 2 demos are now present at ...

kulminaator

Maybe this thread should be moved to graphics topics ? I doubt there will be many useful answers on the directfb&fusion for a while in the raspberry community, maybe you are better off asking these questions in directfb mailing lists ? (it's such a shame that directfb seems complicated to get to wor...

kulminaator

i have done a small amount of research, over the last 2 weeks, on the possible graphics programming libraries on the raspberry pi ... So to save the time of others, i will add my conclusions here (august 2012 state this is) * Casual X11 stuff (2D/3D) (any graphics toolkit that comes to your head) - ...

kulminaator

i threw the modified code here :
http://pastebin.com/TuLTEqpq

* note that the time estimation is done on full seconds, so it's not extremely accurate, but accurate enough for reasonable tests.

kulminaator

great work on openvg :) i played around with the original program from the the top of the thread: moved srand out from the rshapes() , threw the the rshapes inside of the while and added some timing stuff to make it last for 10 seconds and counting the frames during that ... whilst the drawing stuff...

kulminaator

so my current state is this ... .directfbrc is like this: system=egl mode=1280x720 depth=16 some of the tests run, some of then "run" and some just crash df_matrix - appears to work df_dok - initially appears to work, but stuff seems to be rendered into a buffer offscreen and then blitted onto the s...

kulminaator

thanks for the help, seems that it helped a bit: $ sudo /opt/directfb/bin/dfbinfo ~~~~~~~~~~~~~~~~~~~~~~~~~~| DirectFB 1.6.1 |~~~~~~~~~~~~~~~~~~~~~~~~~~ (c) 2001-2012 The world wide DirectFB Open Source Community (c) 2000-2004 Convergence (integrated media) GmbH -------------------------------------...

kulminaator

and yet it seems that my output is not accelerated after this build running sudo ./dfbinfo shows this : ~~~~~~~~~~~~~~~~~~~~~~~~~~| DirectFB 1.6.1 |~~~~~~~~~~~~~~~~~~~~~~~~~~ (c) 2001-2012 The world wide DirectFB Open Source Community (c) 2000-2004 Convergence (integrated media) GmbH ---------------...

kulminaator

just to make sure we're on the same page, i'm building the lib again with your latest configure line, right now the output of configure looks like this: http://pastebin.com/u3PR0X2g

draconis, can you show your configure output and how did you overcome the pkg-config issue ?

kulminaator

from my point of view raspberry pi is a robotics fan's dream :) 1) it's cheap as hell, it's simple as hell to set up 2) you don't have to reinvent the wheel to get a working tcp/ip stack, networking, device support 3) raw gpio access 4) moderate power usage (heavyweight when compared to atmel, light...

kulminaator

The only point to OpenGLES and OpenVG usage is hardware acceleration. You will never draw stuff into the framebuffer with the same speed on the raspberry pi's cpu "power". Running the omxplayer vs mplayer fbdev on an mpeg4 file is probably the best example of performance difference. And i sort of te...

kulminaator

I tried to mimic the expected contents of the .pc files so that it would compile and run (and it did), but to me it seemed that the result in the end wasn't really accelerated at all. I was able to run the directfb demos, but it claimed to be drawn by some software rasterizer, so i think the hw acce...

kulminaator

Seems like i'm hitting a first obstacle already while trying to compile directfb 1.6.1 It looks like configure is calling pkg-config for the libEGL, to understand where it's installed, but there is no egl.pc in the /opt/vc folder tree or anywhere else in my system right now, hence my config.log cont...

kulminaator

i got mine from farnell a week ago, took around 5 days to get it (from one side of europe to another ... )

kulminaator

For those more familiar with directfb, as i understand it provides us with accelerated graphics and input abstraction layer ... sounds more than enough to create decent applications on the device (considering the memory and cpu power of raspberry pi) ? Do we still have to compile the lib by hand or ...

Search found 23 matches

Re: Controlling many servos from rpi by the help of some avr

Re: Gertboard AVR without Arduino IDE (howto)

Re: Gertboard AVR without Arduino IDE (howto)

Controlling many servos from rpi by the help of some avr-s

Re: Example program to draw random shapes using the C compil

Re: Small WiFi adaptor

Re: a small roundup of graphics

Re: a small roundup of graphics

Yet another demo of OpenVG

Re: Directfb/Pi

a small roundup of graphics

Re: Example program to draw random shapes using the C compil

Re: Example program to draw random shapes using the C compil

Re: Directfb/Pi

Re: Directfb/Pi

Re: Directfb/Pi

Re: Directfb/Pi

Re: Why not program on x86 desktop?

Re: Using the least memory

Re: Directfb/Pi

Re: Directfb/Pi

Re: in stock for next working day delivery

Re: Directfb/Pi