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by ab1jx
Sun Feb 17, 2019 4:28 am
Forum: C/C++
Topic: Finally kicked this one out the door
Replies: 2
Views: 87

Re: Finally kicked this one out the door

ss1550297381_4x_800.jpg
ss1550297381_4x_800.jpg (59.72 KiB) Viewed 84 times
1 image per post apparently
by ab1jx
Sun Feb 17, 2019 4:24 am
Forum: C/C++
Topic: Finally kicked this one out the door
Replies: 2
Views: 87

Finally kicked this one out the door

https://sourceforge.net/projects/fbgrad/ I've been playing with it longer than I should have. gradient_pp_export_rot_gam95_300.jpg It runs with X or without (on a Pi), under Debian on my laptop it gives "no space left on device" trying to write to the framebuffer with X running. Ctrl-alt-f2 to a vir...
by ab1jx
Thu Feb 14, 2019 12:46 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

Hee-hee, ya gotta try this: Near the end of fbinit() change this line: maxdist = sqrt((xres * xres) + (yres * yres)); to maxdist = sqrt((xres * xres) + (yres * yres))/7.0; I wasn't happy with the muted colors. They happen because I want to scale the resulting distances from the screen edges to every...
by ab1jx
Wed Feb 13, 2019 4:23 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

Yep, the fun of doing graphics without X11 ;) Don't know why everyone insists on multi windowing, multi user, multi tscking OS's. One user, one task, one window is much easier. Well mostly it just turned out that way. My SDR program has 3 threads already and I haven't even gotten to demodulation. 1...
by ab1jx
Wed Feb 13, 2019 1:58 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

I gotta stop playing and get back to work. I ran across somebody's Python demo of how to use a Pi framebuffer doing color gradients and thought well, I always wanted to play with gradients too, but in C. For each frame 3 screen edges are selected at random, then a point in a random position om each ...
by ab1jx
Tue Feb 12, 2019 2:37 pm
Forum: Bare metal, Assembly language
Topic: Writing to the framebuffer is slow
Replies: 23
Views: 3813

Re: Writing to the framebuffer is slow

My approach to doing this. You don't need to mess with mailboxes anymore, that's built into the kernel now. You open /dev/fb0, mmap to get a pointer and write to it. You need to keep track of what goes where but it's the same as writing into an image buffer then calling libjpeg or libpng to write it...
by ab1jx
Mon Feb 11, 2019 11:38 pm
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

You have me wondering how hard is it to turn the Pi's RF combo chips into channel scanners. Aw, just get your basic $20 dongle like https://www.nooelec.com/store/sdr/sdr-receivers/nesdr-mini-rtl2832-r820t.html I bought a cheaper Chinese knockoff for US $12 which sort of works. The biggest shortcomi...
by ab1jx
Mon Feb 11, 2019 3:33 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

I found my bug the old fashioned way, by thinking about it. I hadn't touched this project in most of a year. I knew I needed to init the dongle so I stuck that in and it worked. Then I have a function that starts up my threads so I stuck that in and boom. The thread init starts up the rf function wh...
by ab1jx
Sun Feb 10, 2019 7:54 pm
Forum: General discussion
Topic: Phone camera details, standards, etc
Replies: 4
Views: 174

Re: Phone camera details, standards, etc

I was mostly just killing time in a power outage when not much worked besides phones. The Spec Device app tells me some stuff about my phone's camera and there's a database of user-scanned phones at http://specdevice.com/unmoderated.php A while back this article appeared https://techcrunch.com/2018/...
by ab1jx
Sun Feb 10, 2019 2:58 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

Thank you, that should come with hello_fft or at least a link to it. I've read some of Herman Hermitage's stuff. I have directories marked QPULib, rpi-playground, vc4-gpu-tools, vc4asm, videocoreiv-qpu. Much of it crashes on a Pi 3B because I guess it dates back to a Pi 1 and an address was differen...
by ab1jx
Sat Feb 09, 2019 8:20 pm
Forum: General discussion
Topic: Phone camera details, standards, etc
Replies: 4
Views: 174

Phone camera details, standards, etc

I stumbled across this 2 part article, the 2nd part implies you can take the actual camera off a Pi camera board and replace it with one from a phone. Not exactly a confidence-inspiring surplus of details though. part1 https://www.electroschematics.com/9767/mobile-phone-camera-interface/ part 2 http...
by ab1jx
Sat Feb 09, 2019 8:05 pm
Forum: General discussion
Topic: Using Hard Drive with Raspberry Pi
Replies: 46
Views: 23033

Re: Using Hard Drive with Raspberry Pi

For anybody that just wants to recover some files off a hard drive from a conventional computer take a look at the StarTech USB3SSATAIDE. It has a connector that fits SATA on one side and IDE on the other. Whatever you use it with needs to speak the filesystem system you have on the drive though, bu...
by ab1jx
Sat Feb 09, 2019 7:29 pm
Forum: C/C++
Topic: what is memory barrier
Replies: 8
Views: 2975

Re: what is memory barrier

I also read it's a ARMv8, but I also read about ARM53 for the Pi3 (and new OPi2) - just curious about what's true and what's the diffeence in case. The CPU name is Cortex-A53 It is ARMv8 architecture and can support both AArch64 and the 32-bit modes (A32 and T32). It has the latest version of NEON ...
by ab1jx
Thu Feb 07, 2019 2:29 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

[ You were attempting to dereference a void*. You declared copyto as being a pointer to void, then you used it as an array by assigning a value to the ith element from it, the array access needs to dereference copyto so you end up with t looks like you meant to have copyto be a void**, that could b...
by ab1jx
Wed Feb 06, 2019 6:03 pm
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

There isn't really a good reason to restore the framebuffer, it's mostly a courtesy to the user. If you just drag a window over the affected area afterwards X generates expose events and repaints the area good as new. black_1024x768.jpg Here I was backing up the area to memory and I added a bzero() ...
by ab1jx
Wed Feb 06, 2019 3:47 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

framebuffer for your waterfall, as long as you don't mind that such a window would be "invisible" to the framebuffer or X11. That way the hardware does the composition as it generates the video display and the window's contents never actually get copied to the famebuffer. For some reason I expected...
by ab1jx
Tue Feb 05, 2019 5:18 pm
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

If you have the batteries and inverter and all that I would think 3 KW worth of panels would do unless you have electric heat. Not sure about A/C. Newer panels are slightly more efficient but still only about 13% I think. That's why the heat collecting ones are good, much more efficient. I used to h...
by ab1jx
Tue Feb 05, 2019 4:57 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

These little ARM chips can execute Java bytecode directly I think, it's built into their instruction set. Most of what happens in millions of Android phones is in Java because there's no real speed penalty like with old style interpreted Java bytecode. The compiler doesn't actually make an executabl...
by ab1jx
Tue Feb 05, 2019 2:05 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

Hey I got some of those PB137 years ago, never got around to using them as I still have to get a spare panel. Might have a look for secondhand refit panels, sometimes going free if you take them away ;) What language/toolset are you using? Language/toolset is just plain GCC in retirement. Used to d...
by ab1jx
Mon Feb 04, 2019 1:51 pm
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

That's probably more down to the timer resolution than anything. If you start at dead on a second (e.g. 0.0s) then your loop will run for ~10 seconds. If however you start part way through a second (e.g. 0.9s) then your loop will only run for ~9.1s and at ~100 lines per second that accounts for ~90...
by ab1jx
Mon Feb 04, 2019 7:51 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

No real interest in doing baremetal without Linux. I used OpenBSD for about 15 years but Linux has a bigger userbase so it's more refined. A lot of things won't build under OpenBSD, it's like pulling hen's teeth. And I like Firefox, Libre Office, Gimp, I couldn't do baremetal. Even my Zeroes have Ra...
by ab1jx
Mon Feb 04, 2019 2:02 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

Hmm, I can't afford to fly to Europe. I have a few dishes, mostly TVRO, but one big old 4 footer I grabbed from the dump andnever used. For all those MHz up there not much of it's very interesting. I happened to hear the state police catching the Boston Bomber a few years back at 900+ MHz. A real si...
by ab1jx
Sun Feb 03, 2019 4:06 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

There's always /opt/vc/src/hello_pi/hello_fft as an example. Not sure if it's really going to be faster than fftw or not but it's one less thread. Passing stuff back and forth to and from the GPU may be slower than what you gain. Computers are a lot faster than in 8088 days. I have a gphoto project ...
by ab1jx
Sun Feb 03, 2019 2:44 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

Now I'm not sure what to think. I used this code https://stackoverflow.com/questions/19542029/how-to-get-pixel-colour-from-framebuffer-on-linux-raspberry-pi and it not only worked, it seemed very fast. They open /dev/fb0 (standard framebuffer device) as a file, then use mmap() to get a pointer. So v...
by ab1jx
Sat Feb 02, 2019 2:47 pm
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 49
Views: 1213

Re: My es2gears went black

Only £149.99 (inc VAT) That can wait, that's for sure (Trilby hat) I don't have a 3B+, just 3 3Bs, don't plan on buying one. I'd be more apt to get a RockPro64 https://www.pine64.org/?page_id=61454 but I'm definitely interested in a 14 inch Pinebook when they're available again. https://www.pine64.o...

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