Go to advanced search

by HermannSW
Wed Jul 28, 2021 9:59 am
Forum: General discussion
Topic: holographic display ?
Replies: 2
Views: 113

Re: holographic display ?

Who needs a display for holograph? ;-)
https://www.dailymotion.com/video/xqs493
holograph.anim.gif
holograph.anim.gif
holograph.anim.gif (136.43 KiB) Viewed 46 times
by HermannSW
Wed Jul 28, 2021 8:25 am
Forum: Camera board
Topic: Low latency image captures
Replies: 4
Views: 116

Re: Low latency image captures

While the solution requires small amount of hardware, it is only needed for inverting 39ns long high signal, and for adapting Raspberry 3.3V to HQ camera XVS pin 1.8V. The pulse is generated in software, so just fits your reqirements. See nanopulse.c software in posting I pointed to.
by HermannSW
Wed Jul 28, 2021 7:25 am
Forum: Camera board
Topic: Low latency image captures
Replies: 4
Views: 116

Re: Low latency image captures

First, I strongly believe that you will get lower latency with C/C++ (raspistill userland or libcamera code) than with picamera. How about 40 nanoseconds(!) latency? This solution allows for triggering a frame capture at any point in time you want, with any shutter time you specify (arbitrary long s...
by HermannSW
Tue Jul 27, 2021 6:49 am
Forum: C/C++
Topic: C++ development for the Raspberry
Replies: 5
Views: 295

Re: C++ development for the Raspberry

Pi0 is a single core CPU, not really suited for compilation of big projects. What you want is cross compilataion, that is possible. But compilation on quad core Pi4B (or better Pi400 that is faster with default values) will speed up greatly. Using USB storage instead of micro SD card will speed up e...
by HermannSW
Mon Jul 26, 2021 8:07 pm
Forum: Camera board
Topic: HQ camera 1012x760@130fps with raspiraw
Replies: 1
Views: 183

Re: HQ camera 1012x760@130fps with raspiraw

I did 1012x760 investigations more than a year ago: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=109137&p=1664816#p1665535 At that time my focus was on average framerate, not on 0 frame skips. This video was captured free running, without specifying framerate, and resulted in 165f...
by HermannSW
Sun Jul 25, 2021 10:35 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C scan not detecting a device that the Arduino detects
Replies: 3
Views: 155

Re: I2C scan not detecting a device that the Arduino detects

Did you run i2cdetect against the correct bus?
What does "ls -l /dev/i2c*" show?
by HermannSW
Sat Jul 24, 2021 1:42 pm
Forum: Camera board
Topic: Creating a RPI-assisted microscope
Replies: 125
Views: 37468

Re: Creating a RPI-assisted microscope

In the previous two posting I summarized on 0.21µm/pixel distance resolution, and 5µm/step or better for x/y/z positioning of 180° M12 lens mounted reversed Raspberry HQ camera macro lens microscope. The best micrometer sliders I own have DIV=0.01mm, that is 10µm between neighboring slider divisions...
by HermannSW
Sat Jul 24, 2021 1:16 pm
Forum: Camera board
Topic: Creating a RPI-assisted microscope
Replies: 125
Views: 37468

Re: Creating a RPI-assisted microscope

Superglueing cheap 28BYJ48 stepper motor to microscope stand ... https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=210605&p=1892784#p1679128 https://www.raspberrypi.org/forums/download/file.php?id=37795 ... allows for 4.4µm/step vertically (z-direction) with half stepping, allowing for...
by HermannSW
Sat Jul 24, 2021 1:00 pm
Forum: Camera board
Topic: Creating a RPI-assisted microscope
Replies: 125
Views: 37468

Re: Creating a RPI-assisted microscope

After a year I will revisit this project, and enhance further -- thanks for unlocking this thread. First statements on results achieved sofar, here for "distance resolution" as distance per pixel, not what length can be cleanly captured per pixel of HQ camera. Mounting 180° M12 lens revers...
by HermannSW
Fri Jul 23, 2021 5:14 pm
Forum: Camera board
Topic: libcamera version of raspistill etc. available
Replies: 55
Views: 6098

Re: libcamera version of raspistill etc. available

Thanks for the hints. Yesterday I played with raspiraw, and had to comment out imx477 dtoverlay. Today I uncommented that overlay, and commented my .bashrc workaround. After reboot libcamera-hello just works, nothing more needed. So what you told seems to be correct, since a simple reboot compared t...
by HermannSW
Fri Jul 23, 2021 12:50 pm
Forum: Camera board
Topic: Longtime exposures with HqCam
Replies: 1
Views: 92

Re: Longtime exposures with HqCam

Raspistill maximal exposure for HQ camera is 239 seconds. I developed method that allows for arbitrary long exposures. It misuses XVS pin of HQ camera to use single HQ camera in slave mode. No additional software needed, triggering can be done from python or pigpio: https://www.raspberrypi.org/forum...
by HermannSW
Thu Jul 22, 2021 7:43 pm
Forum: Camera board
Topic: HQ camera 1012x760@130fps with raspiraw
Replies: 1
Views: 183

HQ camera 1012x760@130fps with raspiraw

Lately I realized that HQ camera allowed only for low framerates with libcamera-vid: "Re: How to get more than 40fps with libcamera-vid?" https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=316098&p=1891383#p1891383 Today I cloned and built these repos: https://github.com/raspb...
by HermannSW
Thu Jul 22, 2021 4:50 am
Forum: General discussion
Topic: Pi 400 case
Replies: 11
Views: 473

Re: Pi 400 case

no like a case like the pi 4 has a case/box like the pi 400 would not have the keyboard but just the tech You can easily open Pi400 case and disconnect keyboard cable. I opened and added RTC to my Pi400: https://www.raspberrypi.org/forums/viewtopic.php?f=140&t=309191&p=1849682&hilit=Rtc...
by HermannSW
Thu Jul 22, 2021 4:32 am
Forum: General discussion
Topic: Is there any very small screen?
Replies: 6
Views: 226

Re: Is there any very small screen?

I use cheap 320x240 2.2" ili9341 LCDs for that. Below streams live video on left and edge detected video on right display: https://www.raspberrypi.org/forums/viewtopic.php?f=44&p=1649091#p1648336 https://stamm-wilbrandt.de/en/forum/IMG_20171002_214631.jpg I always used SPI versions of those...
by HermannSW
Tue Jul 20, 2021 5:29 pm
Forum: Camera board
Topic: libcamera version of raspistill etc. available
Replies: 55
Views: 6098

Re: libcamera version of raspistill etc. available

I wanted to test libcamera-jpeg, and used micrometer slide that I got today from visitor here in hospital. I don't know what CS lens I use (will have to look at camera boxes at home). I would never have thought that a camera can "just be" a microscope: 20210720_190535.15%.jpg This command ...
by HermannSW
Tue Jul 20, 2021 4:46 pm
Forum: Camera board
Topic: How to get more than 40fps with libcamera-vid?
Replies: 6
Views: 200

Re: How to get more than 40fps with libcamera-vid?

(2) had no effect for capturing 1332x990, but increased maximal framerate without frameskips to 640x480@92fps (from 640x480@83fps): pi@raspberrypi4B:~ $ libcamera-apps/build/libcamera-vid --framerate 118 \ > -t 8000 --save-pts /dev/shm/t.pts --width 640 --height 480 -o /dev/shm/t.h264\ > --denoise c...
by HermannSW
Tue Jul 20, 2021 4:33 pm
Forum: Camera board
Topic: How to get more than 40fps with libcamera-vid?
Replies: 6
Views: 200

Re: How to get more than 40fps with libcamera-vid?

There are a few things you can do to improve framerates: I don't think libcamera does a release build by default (not totally sure though). Use something like "meson build -Dbuildtype=release" Run with the option "--denoise cdn_off". Updating the text on the title window is surp...
by HermannSW
Tue Jul 20, 2021 10:41 am
Forum: Camera board
Topic: libcamera version of raspistill etc. available
Replies: 55
Views: 6098

Re: libcamera version of raspistill etc. available

I did complete sync of libcamera-apps and rebuilt, libcamera-base is not found, not sure why. But I can live with the .bashrc workaround, in case it is only my Raspberry Pi OS that shows the issue. On the weekend I had to recover my SD card OS, perhaps something got lost that way: https://www.raspbe...
by HermannSW
Tue Jul 20, 2021 10:27 am
Forum: Camera board
Topic: libcamera version of raspistill etc. available
Replies: 55
Views: 6098

Re: libcamera version of raspistill etc. available

Thanks, I will do recursive delete of libcamera-apps directory and then do complete fresh build according README.md -- before I commented out the .bashrc workaround and opened new terminal window. One camera lib is found, the other not: pi@raspberrypi4B:~ $ echo $LD_LIBRARY_PATH pi@raspberrypi4B:~ $...
by HermannSW
Tue Jul 20, 2021 9:50 am
Forum: Camera board
Topic: How to get more than 40fps with libcamera-vid?
Replies: 6
Views: 200

Re: How to get more than 40fps with libcamera-vid?

Hi, we are aware of this and it has been discussed previously (for example, https://github.com/raspberrypi/libcamera-apps/issues/26). Unfortunately we don't have a solution just yet, but if you're happy to edit this line and change the value 1000 to (studying the output log...) something smaller th...
by HermannSW
Tue Jul 20, 2021 8:43 am
Forum: Camera board
Topic: libcamera version of raspistill etc. available
Replies: 55
Views: 6098

Re: libcamera version of raspistill etc. available

I made the workaround permanent:

Code: Select all

$ tail -1 ~/.bashrc 
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib/arm-linux-gnueabihf
$ 

But README.md should really be corrected:
https://github.com/raspberrypi/libcamer ... /README.md
by HermannSW
Tue Jul 20, 2021 8:41 am
Forum: Camera board
Topic: STICKY: libcamera - open source camera stack
Replies: 122
Views: 28932

Re: STICKY: libcamera - open source camera stack

README.md is missing something: https://github.com/raspberrypi/documentation/blob/master/linux/software/libcamera/README.md When trying to run ./libcamera-hello, libraries are not found. This is my permanent workaround, that makes all libcamera-apps work: $ tail -1 ~/.bashrc export LD_LIBRARY_PATH=$...
by HermannSW
Mon Jul 19, 2021 7:25 pm
Forum: Camera board
Topic: How to get more than 40fps with libcamera-vid?
Replies: 6
Views: 200

How to get more than 40fps with libcamera-vid?

Lower framerates get accepted, but not higher. This command pi@raspberrypi4B:~/libcamera-apps/build $ LD_LIBRARY_PATH=/usr/local/lib/arm-linux-gnueabihf ./libcamera-vid --framerate 60 -t 4000 --save-pts t.pts --width 1332 --height 990 -o t.h264 captures only with 40fps: pi@raspberrypi4B:~/libcamera-...
by HermannSW
Mon Jul 19, 2021 6:42 pm
Forum: Camera board
Topic: libcamera version of raspistill etc. available
Replies: 55
Views: 6098

Re: libcamera version of raspistill etc. available

Next problem, libcamera-apps compiled successfully. Readme.md asks me to test all is fine: To check everything is working correctly, type ./libcamera-hello - you should see a preview window displayed for about 5 seconds. But something was not installed correctly -- is README.md missing a step I need...
by HermannSW
Mon Jul 19, 2021 6:24 pm
Forum: Camera board
Topic: libcamera version of raspistill etc. available
Replies: 55
Views: 6098

Re: libcamera version of raspistill etc. available

@therealdavidp Thank you, I recursively removed libcamera directory. I had problems cloning with git protocol, so used https instead: git clone https://git.linuxtv.org/libcamera.git This is the hash: pi@raspberrypi4B:~/libcamera $ cat .git/refs/heads/master ab09913acbb0c00a74ff6498fa9b52f8d74548fa p...

Go to advanced search