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by ab1jx
Thu Mar 14, 2019 1:37 pm
Forum: Graphics programming
Topic: A New Flowcharting Program
Replies: 10
Views: 4741

Re: A New Flowcharting Program

My new idea: make a library of flowchart symbols for gschem and use that. export1.png I was working on this schematic last night and it occurred to me that's what I'm looking for in a flowchart program. The red dots are unused attachment points. Put your mouse cursor over one and hit n (net) and you...
by ab1jx
Thu Mar 07, 2019 10:34 pm
Forum: Troubleshooting
Topic: SD Card reliability debate ...
Replies: 12
Views: 8496

Re: SD Card reliability debate ...

Well, well, just in time to make bad press. I bought 1 Transcend 400 128 GB card for $65 just under a year ago because Sandisk doesn't make a 128 GB High Endurance, at least not then. The review I read about using High Endurance cards gave them a glowing review. Well, it's being flaky . It's in a Pi...
by ab1jx
Tue Mar 05, 2019 4:27 pm
Forum: Windows 10 for IoT
Topic: Home Automation with the Pi 3
Replies: 7
Views: 8334

Re: Home Automation with the Pi 3

It works much better to do a little simple analysis on the numbers. 3years.png If you look at the heating and cooling degree days you can sort of see it. Compare July 2018 with 2017. Then again there's a certain amount of randomness. July 2016 and 2017 were almost the same. There are significantly l...
by ab1jx
Tue Mar 05, 2019 4:15 pm
Forum: Windows 10 for IoT
Topic: Home Automation with the Pi 3
Replies: 7
Views: 8334

Re: Home Automation with the Pi 3

I was sort of looking at why there are so many skeptics about global warming and people who'd rather not believe it. I tried overlaying one year's plot over the other, that didn't work very well. About the only thing this is useful for is to look at and say "Yup, this is March, should be warming up ...
by ab1jx
Sun Mar 03, 2019 5:44 pm
Forum: Troubleshooting
Topic: SD Card reliability debate ...
Replies: 12
Views: 8496

Re: SD Card reliability debate ...

Hmm, would there be any point in having software tools for Linux that specifically test/exercise/troubleshoot SD cards? Seems like people in the business probably have stuff we don't. They aren't actually hard drives but about all we have is fsck. Seems like just going through all the files and re-w...
by ab1jx
Sat Mar 02, 2019 3:23 pm
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 52
Views: 3164

Re: My es2gears went black

Let me try to explain the decimation problem. It's common in SDR to throw out data points in the incoming stream before the FFT because well, an RTL2832 dongle cranks out 2 million samples/second or so and you don't need to keep them all. The sample rate affects the overall bandwidth, the frequency ...
by ab1jx
Sat Mar 02, 2019 2:39 am
Forum: Troubleshooting
Topic: My es2gears went black
Replies: 52
Views: 3164

Re: My es2gears went black

Well, I'm still playing with framebuffer graphics. I have 4 threads (so far) for getting data from the RTL2832 dongle over USB, putting it through FFTWF, plotting the spectrum (top part) and another for scrolling the waterfall. I can actually see real-world signals out there but I'm still trying to ...
by ab1jx
Wed Feb 20, 2019 7:26 pm
Forum: Bare metal, Assembly language
Topic: Writing to the framebuffer is slow
Replies: 24
Views: 7342

Re: Writing to the framebuffer is slow

He is working baremetal there is no such thing as /dev/fb0 which is a linux O/S construct and you need linux for it to work. You need to be careful in this section historically it was just baremetal no linux or O/S at all. OK, I got here by search engine, didn't notice the Bare metal, Assembly lang...
by ab1jx
Mon Feb 18, 2019 2:52 pm
Forum: C/C++
Topic: Finally kicked this one out the door
Replies: 4
Views: 912

Re: Finally kicked this one out the door

They aren't actually interference patterns, they just work a little that way. The basic color assigned to every pixel on the screen is a function of its distance from 3 random points on the edges. In the last picture they're upper left, lower left, and near lower left. The bands (and they vary with ...
by ab1jx
Sun Feb 17, 2019 4:28 am
Forum: C/C++
Topic: Finally kicked this one out the door
Replies: 4
Views: 912

Re: Finally kicked this one out the door

ss1550297381_4x_800.jpg
ss1550297381_4x_800.jpg (59.72 KiB) Viewed 909 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: 4
Views: 912

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: 52
Views: 3164

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: 52
Views: 3164

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: 52
Views: 3164

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: 24
Views: 7342

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: 52
Views: 3164

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: 52
Views: 3164

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: 338

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: 52
Views: 3164

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: 338

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: 32427

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: 4244

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: 52
Views: 3164

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: 52
Views: 3164

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: 52
Views: 3164

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...

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