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by HermannSW
Fri Jul 12, 2019 2:03 pm
Forum: Camera board
Topic: High framerate raspivid (initially 640x480 at 180fps)
Replies: 25
Views: 8063

Re: High framerate raspivid (initially 640x480 at 180fps)

Just to report success on 9kHz PWM flashes resulting in 9000eps frame captured. The airgun pellet got captured 10 times in this frame had speed 96.9m/s, with 96.9m/s / 9000Hz = 1.077cm between exposures. Comparing apples with oranges, but multiple exposure really allows for so much higher eps rates ...
by HermannSW
Fri Jul 12, 2019 1:50 pm
Forum: Camera board
Topic: The difference between capture_continuous and capture_sequence
Replies: 3
Views: 232

Re: The difference between capture_continuous and capture_sequence

> raspiraw allows a capture of raw data through the video port but that is restricted to more limited resolution and FOV as far as I can make out > Why? You can capture all modes with v1/v2 camera and raspiraw as described in the two tables in doc, search for "--mode": https://www.raspberrypi.org/do...
by HermannSW
Fri Jul 05, 2019 12:06 pm
Forum: Camera board
Topic: Review: Graspinghand gooseneck camera mount
Replies: 10
Views: 731

Re: Review: Graspinghand gooseneck camera mount

Today I got Scorpi B+ and tried it, with the first camera module I found and that was a v1 NoIR camera with 70mm lens: https://stamm-wilbrandt.de/en/forum/IMG_050719_133959.part.jpg Scorpi B+ is really dangerous with v1 NoIR clone camera! I first screwed the lower mounting whole and did not realize ...
by HermannSW
Thu Jul 04, 2019 1:57 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 30
Views: 3354

Re: Raspberry v1 camera global (external) shutter videos

I am currently working on sub-project "ESP32-CAM ov2640 sensor global external shutter" and created a sub repo already: https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter/tree/master/FCameraWebServer The most difficult part after hardware reverse engineering the ov2640 sensor ...
by HermannSW
Thu Jul 04, 2019 6:52 am
Forum: Camera board
Topic: v2 camera can capture 1000fps videos ...
Replies: 34
Views: 9273

Re: v2 camera can capture 1000fps videos ...

> The main timing module is a GPS disiplined clock with thousandths resolution. 100 fps against this time source would be perfect. > Be aware that while you could do gstreamer timeoverlay in pipeline while recording, it will drop raspivid's framerate significantly. That was the reason that I did the...
by HermannSW
Wed Jul 03, 2019 10:30 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: PWM specs
Replies: 3
Views: 246

Re: PWM specs

What is the resolution of the PWM the pi3 is capable of (%DC)? With software PWM between 320Hz and 16000Hz with pigpio library: http://abyz.me.uk/rpi/pigpio/pigs.html#PFS How many pins on the header are PWM capable? All pins can do software PWM. In addition Pi allows for two hardware PWMs [GPIO(12|...
by HermannSW
Tue Jul 02, 2019 3:25 pm
Forum: Networking and servers
Topic: Raspberry PI with arduino = TCP/IP
Replies: 7
Views: 388

Re: Raspberry PI with arduino = TCP/IP

> on the Rpi > You don't state which Rpi, in case of Pi0 you need to add network connectivity either by USB OTG or enc28j60 network module: https://www.raspberrypi.org/forums/viewtopic.php?p=1015300#p1015300 You don't state which arduino, you can add network connectivity to AVR based Arduinos with e...
by HermannSW
Tue Jul 02, 2019 10:11 am
Forum: Camera board
Topic: v2 camera can capture 1000fps videos ...
Replies: 34
Views: 9273

Re: v2 camera can capture 1000fps videos ...

I forgot that I posted the exact steps needed in this posting:
https://www.raspberrypi.org/forums/view ... e#p1294557

For timestamp 8467.329 from .pts file:
Image
by HermannSW
Sun Jun 30, 2019 10:46 pm
Forum: Camera board
Topic: v2 camera can capture 1000fps videos ...
Replies: 34
Views: 9273

Re: v2 camera can capture 1000fps videos ...

You can capture Raspberry v2 camera with up to 120fps (limit is 200fps) as .h264 video with raspivid. Using -pts option you will get a file of microsecond reolution timestamps for each and every frame. Using mkvmerge you can merge the .h264 video and timestamps file into a video where each frame kno...
by HermannSW
Sun Jun 30, 2019 10:29 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Do GPIO output pins bounce?
Replies: 3
Views: 335

Re: Do GPIO output pins bounce?

To answer your question , GPIO outputs are glitch free. That is good to hear! I do control 38V/1.5A led drivers powering a 5000lm led via two 24V IRF520 mosfets in series. GPIO13 is connected to SIG pin of both IRF520 modules. When Pi GPIO13 goes from high to low I would expect this: ‾‾‾‾‾‾‾‾|_____...
by HermannSW
Sat Jun 29, 2019 8:08 pm
Forum: C/C++
Topic: Quick log2????
Replies: 35
Views: 1273

Re: Quick log2????

ARM has the "cnt" instruction to do that ("popcnt" on Intel). and gcc has the __builtin_popcount() intrinsic to produce the "cnt" instruction. Interesting, I did not know that. I looked up quite some documents on cnt and popcnt and cannot find information on the cycles the instructions need. Do you...
by HermannSW
Sat Jun 29, 2019 7:52 pm
Forum: C/C++
Topic: Quick log2????
Replies: 35
Views: 1273

Re: Quick log2????

> How do you quickly determine the maximum set bit in a number in a minimal number of operations in C? > I can only answer the minimal number for minimum set bit , and that is constant: y = x; x &= (x-1); // deletes last bit set y ^= x; There are different algorithms to determine the number of bits ...
by HermannSW
Thu Jun 27, 2019 6:40 pm
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 20
Views: 2208

Re: pigpio C sub µs single pulse generation

I am working on getting global external shutter done with ESP32-CAM ov2640 sensor (a predecessor of Raspberry v1 ov5647 sensor which does global external shutter captures nicely). After I learned how to solder a cable to one of 24 pins of ESP32-CAM module flat ribbon cable connector (0.5mm spaced!) ...
by HermannSW
Wed Jun 26, 2019 5:57 pm
Forum: Camera board
Topic: Stereo Vision on Raspberry Pi 3B+
Replies: 14
Views: 1239

Re: Stereo Vision on Raspberry Pi 3B+

There is a new/interesting/surprising way to get dual camera support for the Pi3B+ (requires carefully de-soldering the main processor and LPDDR2 chip, no Pi clone): http://www.arducam.com/shrink-your-raspberry-pi-into-a-40x25mm-somsystem-on-module/ https://stamm-wilbrandt.de/en/forum/Pi.SoM.Dual_Ca...
by HermannSW
Wed Jun 26, 2019 11:32 am
Forum: Camera board
Topic: best compromise quality/size for time-lapse camera
Replies: 19
Views: 1315

Re: best compromise quality/size for time-lapse camera

ok thank you, so y_data values are between 0 and 255? Yes, 0..255 range. From picamera doc on yuv you can see each pixel taking a byte in Y-plane: https://picamera.readthedocs.io/en/latest/recipes2.html#unencoded-image-capture-yuv-format https://picamera.readthedocs.io/en/latest/_images/yuv420.svg
by HermannSW
Wed Jun 26, 2019 10:49 am
Forum: Camera board
Topic: Camera and new Raspi4.
Replies: 1
Views: 453

Re: Camera and new Raspi4.

Will be better, use wired Gigabit Ethernet than wifi?. Definitely, even with Pi3B I was able to get 186Mbit/s from a 400Mbit/s line, while Wifi is much slower than that. Do you think that raspberry pi org will release new cameras with 4k? I cannot speak for RPF. I just looked up what 4k resolution ...
by HermannSW
Wed Jun 26, 2019 10:01 am
Forum: Camera board
Topic: best compromise quality/size for time-lapse camera
Replies: 19
Views: 1315

Re: best compromise quality/size for time-lapse camera

numpy arrays are weird, I had to use flatten to get a 1-dimensional array of 400*300=120000 bytes: $ cat PYA.py #!/usr/bin/env python import picamera import picamera.array import numpy as np from time import sleep with picamera.PiCamera() as camera: with picamera.array.PiYUVArray(camera) as output: ...
by HermannSW
Wed Jun 26, 2019 8:01 am
Forum: Camera board
Topic: best compromise quality/size for time-lapse camera
Replies: 19
Views: 1315

Re: best compromise quality/size for time-lapse camera

I don't understand in your code how do you loop each pixel and which is the luminance byte, so its value would be between 0-255 right? Hi, I had to learn myself, and my concerns on picamera have been confirmed. This is the diff to iterate (and only count for now) the pixels of the frame: [email protected]...
by HermannSW
Wed Jun 26, 2019 12:40 am
Forum: Camera board
Topic: best compromise quality/size for time-lapse camera
Replies: 19
Views: 1315

Re: best compromise quality/size for time-lapse camera

> I think that PiYUVArray could do the work, but I don't understand how to read the array and count the pixels beyond a threshold that I could consider "darkness" > The example on picamera doc is wrong (misses 3rd argument ":1"), but it explains YUV: https://picamera.readthedocs.io/en/latest/recipes...
by HermannSW
Tue Jun 25, 2019 3:06 pm
Forum: General discussion
Topic: PI4 identify 1,2 or 4GB version
Replies: 4
Views: 845

Re: PI4 identify 1,2 or 4GB version

With running Raspbian:

Code: Select all

vcgencmd get_mem arm
by HermannSW
Tue Jun 25, 2019 2:57 pm
Forum: General discussion
Topic: Cheapest High speed camera up to 900 FPS!!
Replies: 30
Views: 33184

Re: Cheapest High speed camera up to 900 FPS!!

Hi, > Has anyone tested if Raspiraw can scan just a single row of data with very high FPS? > not single row, but few rows. > Theoretically, it should be able to do so around 50k FPS on Raspiraw 3B+ and OV5640 sensor. > Not really, v2 camera maxes out at 1007fps for 640xH modes, v1 camera at 750fps. ...
by HermannSW
Tue Jun 25, 2019 12:35 am
Forum: Camera board
Topic: Pi cameras as [soldering] maginifying glass
Replies: 0
Views: 239

Pi cameras as [soldering] maginifying glass

I used v1 and v2 cameras in this thread extensively: https://www.esp32.com/viewtopic.php?f=19&t=11126 Either with self added M12 mount and lens, or v1 cameras bought with that, the lens allows adjustment to different height above scene sharp images, and therefore different resolutions. First I did u...
by HermannSW
Sun Jun 23, 2019 12:35 am
Forum: HATs and other add-ons
Topic: Qs on official Raspberry Pi [3]A+ Case
Replies: 4
Views: 982

Re: Qs on official Raspberry Pi [3]A+ Case

Got so used to using these headless or via a web page I must try it as a desktop one day... Most of the time I use the Pi3A+ headless via ssh as well (like my other PIs). You may ask why to connect HDMI monitor in that case ‒ for me the reason is raspi(vid|still) camera preview. I need to install o...
by HermannSW
Sat Jun 22, 2019 5:37 pm
Forum: Camera board
Topic: Raspberry no IR-filter camera see-through images
Replies: 0
Views: 863

Raspberry no IR-filter camera see-through images

I have used Raspberry v[12] NoIR cameras only for capturing in the dark sofar, if not capturing at normal daylight. In thread "ESP32-CAM ov2640 exposure control/FREX mode" https://www.esp32.com/viewtopic.php?f=19&t=11126 I try to bring ov2640 sensor into FREX mode as I did with Raspberry v1 camera (...
by HermannSW
Sat Jun 22, 2019 2:46 pm
Forum: HATs and other add-ons
Topic: Qs on official Raspberry Pi [3]A+ Case
Replies: 4
Views: 982

Qs on official Raspberry Pi [3]A+ Case

Today I received my first Pi 3A+ (have Pi0, Pi0W, 2B+, 3B and 3B+ models sofar). Because buying Pi 3A+ plus official Raspberry Pi [3]A+ case allowed for free shipping, with cost less than the cost of Pi 3A+ alone plus shipping, I ordered both. After installing Raspberry Pi Stretch and configuring ca...

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