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by HermannSW
Sat Sep 07, 2019 9:10 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 40
Views: 4574

Re: Raspberry v1 camera global (external) shutter videos

I wanted to see pellet multiple exposures with two speeds in a frame. Pellet needs to collide with something, in order to remove energy and speed. I used a long slightly slated lath for that. I determined where the pellet would need to hit the lath to be in middle of horizontal camera view and marke...
by HermannSW
Sat Sep 07, 2019 2:14 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 40
Views: 4574

Re: Raspberry v1 camera global (external) shutter videos

I went back to the frame that proved fast spinning of airsoft pistol pellet during flight, and created a "fast camera panning" tool to highlight that: https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter#user-content-camera_panning In Sound trigger section the pellet capture wit...
by HermannSW
Fri Sep 06, 2019 6:12 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 40
Views: 4574

Re: Raspberry v1 camera global (external) shutter videos

I did some more shots, intentionally a bit upwards, and with 5KHz in order to get a bit distance between successive pellet exposures. I created a shell script that uses netpbm tools and ffmpeg again to create 5000fps animation from the 5000eps frame. That script is mak.640.5, contained among other s...
by HermannSW
Fri Sep 06, 2019 4:01 pm
Forum: Camera board
Topic: How to zoom Rpi camera v2 ?
Replies: 4
Views: 258

Re: How to zoom Rpi camera v2 ?

Zooming can be done, I once tested a picamera script from @ethanol100 using camera.zoom()
https://www.raspberrypi.org/forums/view ... 4#p1417423

and was really impressed (I seldom use picamera).
In my response posting you can find a sample .webm and youtube video I took with that script.
by HermannSW
Fri Sep 06, 2019 3:56 pm
Forum: Camera board
Topic: Arducam boards not working
Replies: 9
Views: 376

Re: Arducam boards not working

Thank you. Scorpion Vision have provided good support. Dialogue with Arducam now also. Just trying to get system working in a tight timescale. Thank you HermannSW Now capturing at higher res (also required increase of gpu_mem=200 in config.txt following Arducam guidance). Interesting, "Optional Set...
by HermannSW
Fri Sep 06, 2019 9:46 am
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 37
Views: 3253

Re: pigpio C sub µs single pulse generation

I did "git checkout aa45c1c2c5417d2dccd3a7e90fec475aede4f054" in order to get the freeze version. I renamed it and was surprised that neither ".c" nor ".zip" are allowed attachment types in this forum. I did put the file on my webserver: https://stamm-wilbrandt.de/en/forum/audio_shots.freeze.c This ...
by HermannSW
Fri Sep 06, 2019 8:20 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Can MIPI be used with non-official peripherals?
Replies: 13
Views: 4598

Re: Can MIPI be used with non-official peripherals?

However it seems that the MIPI interfaces (I need both DSI and CSI) can only work with the official display & camera, because the driver is built into the GPU. Most of the discussion sofar was on DSI. On the CSI part of OP question, you can bring in your own cameras like Arducam did for their 0.3/1...
by HermannSW
Fri Sep 06, 2019 8:03 am
Forum: General discussion
Topic: Raspberry Pi computer looks down on Earth
Replies: 15
Views: 762

Re: Raspberry Pi computer looks down on Earth

An increase in width to 12 or 18 meters would be nice but don't count on it before the 2030s. The SS-520-5 rocket mentioned in posting https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=250871&p=1531440#p1531324 above has diameter 0.5m, and is smallest orbital rocket both in mass and height: h...
by HermannSW
Fri Sep 06, 2019 1:18 am
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 37
Views: 3253

Re: pigpio C sub µs single pulse generation

Thanks for the information. > There may be a problem starting a new wave before the previous one has completed. > I was able to recreate the crashes repeatedly, and I did send only one (short) wave in alert function (ten 9µs duration flashes at 6KHz, 1.7ms length in total). Then the program ended. I...
by HermannSW
Thu Sep 05, 2019 8:27 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 40
Views: 4574

Re: Raspberry v1 camera global (external) shutter videos

I wanted to know whether flying pellet spins during flight (it spins fast!). I added small blue dot with permanent marker to north and south pole of some pellets. One pole is visible at least, that should allow to "see" whether there is spin or not. Yesterday I wanted to repeatedly capture shots and...
by HermannSW
Thu Sep 05, 2019 6:38 pm
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 37
Views: 3253

Re: pigpio C sub µs single pulse generation

@joan: The initial commit of audio_shots.c had severe stability issues. When I did 9 shots in a row then the Pi froze completely, power cycling was needed. Sometimes after 2 shots, sometimes after 8. I think I found the reason for this and fixed it with this commit: https://github.com/Hermann-SW/Ras...
by HermannSW
Thu Sep 05, 2019 1:12 pm
Forum: General discussion
Topic: Raspberry Pi computer looks down on Earth
Replies: 15
Views: 762

Re: Raspberry Pi computer looks down on Earth

Assuming a kerosene/LOX or methane/LOX first-stage rocket, the 400-odd tons of fuel consumed in a launch Much less fuel is needed to bring stuff to space, whole rocket weight is 2.6t: https://guinnessworldrecords.com/world-records/smallest-rocket The smallest orbital rocket is SS-520-5, measuring 9...
by HermannSW
Thu Sep 05, 2019 9:51 am
Forum: Automation, sensing and robotics
Topic: Photo transistor as an RPM counter
Replies: 1
Views: 110

Re: Photo transistor as an RPM counter

I used a light barrier with an arduino, but you can do similar with Raspberry and light barrier as well. To avoid junk measurements, a (hardware) Schmitt-Trigger would be helpful. As you can see in this thread I built similar in software (fidget spinner showed 25.09rps or 1505.4rpm): https://forum.a...
by HermannSW
Thu Sep 05, 2019 9:39 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Reading SPI commands
Replies: 2
Views: 126

Re: Reading SPI commands

In addition to using Pi itself for that, you can use usb logic analyzer. Cheap 8CH 24Msps ones start at 4$ (5$ with free shipping): https://www.aliexpress.com/premium/logic-analyzer-usb.html?ltype=premium&d=y&CatId=0&SearchText=logic+analyzer+usb&trafficChannel=ppc&SortType=price_asc&groupsort=1&pag...
by HermannSW
Thu Sep 05, 2019 9:27 am
Forum: Networking and servers
Topic: telnet to serial
Replies: 8
Views: 239

Re: telnet to serial

Perhaps not what you want, but you can connect to Raspberry serial via USB2TTY: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=156541 You can then use minicom or screen tools to login to Raspberry and "telnet" on Raspberry to connect to target. I learned that it is important to get 5V from ...
by HermannSW
Thu Sep 05, 2019 9:08 am
Forum: General discussion
Topic: Raspberry Pi computer looks down on Earth
Replies: 15
Views: 762

Re: Raspberry Pi computer looks down on Earth

Not that high: Pi looks down on earth from 39km high: "'TED BULL STRATOS': RASPBERRY PI CONTROLLED TEDDY BEAR BABBAGE BEATS FELIX BAUMGARTNER'S SKYDIVING RECORD" https://www.independent.co.uk/life-style/gadgets-and-tech/news/ted-bull-stratos-raspberry-pi-controlled-teddy-bear-babbage-beats-felix-bau...
by HermannSW
Wed Sep 04, 2019 11:56 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable/disable SPI without raspi-config or reboot?
Replies: 6
Views: 201

Re: Enable/disable SPI without raspi-config or reboot?

Perhaps not a good idea to use this feature, I found these two messages in "dmesg" output after above commands: [ 7371.068846] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /soc/[email protected]/status [ 7386.818890] OF: overlay: WARNING: memory leak will occur if overlay re...
by HermannSW
Wed Sep 04, 2019 11:13 am
Forum: Automation, sensing and robotics
Topic: Detecting a 24v Impulse via GPIO Pins
Replies: 8
Views: 471

Re: Detecting a 24v Impulse via GPIO Pins

Optocoupler provides electric separation, but at the price of some latency added.
In case latency is too high, a step-down converter might work (4.75-40V to 3.3V):
https://www.aliexpress.com/item/32787217667.html
A 1--6.3 two-resistor voltage divider might do the job as well (1--2 is for 5V->3.3V).
by HermannSW
Wed Sep 04, 2019 9:22 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Enable/disable SPI without raspi-config or reboot?
Replies: 6
Views: 201

Re: Enable/disable SPI without raspi-config or reboot?

sudo dtparam spi=on sudo dtparam spi=off Wow, I did not know about command line use of dtparam. So each statement adds an overlay. [email protected]:~ $ grep spi /boot/config.txt dtparam=spi=on [email protected]:~ $ sudo dtparam spi=off [email protected]:~ $ grep spi /boot/config.txt dtparam=spi=on pi...
by HermannSW
Wed Sep 04, 2019 7:32 am
Forum: Camera board
Topic: Arducam boards not working
Replies: 9
Views: 376

Re: Arducam boards not working

On the 18Mp camera (MIPI), I managed to get this working from Pi 3 B+ basically following your comments. Downloaded all the git-hub material. I did get an error when executing make clean && make (see attachment). opencv issue. Not sure how significant this is? You do get that error because you did ...
by HermannSW
Tue Sep 03, 2019 5:50 pm
Forum: Camera board
Topic: Missing colors
Replies: 3
Views: 128

Re: Missing colors

Or if you're using a NoIR camera in daylight, then that is to be expected. Really? I don't see pink on 90fps NoIR v1 camera frame (robot through sunny grass): https://forum.arduino.cc/index.php?topic=462107.msg3268945#msg3268945 https://stamm-wilbrandt.de/en/forum/downhill_grassy_hiking_trail.jpg S...
by HermannSW
Tue Sep 03, 2019 5:27 pm
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 37
Views: 3253

Re: pigpio C sub µs single pulse generation

Just a short update, audio_shots.c just works, no changes needed; and it enables to find the correct offset needed: (five 9µs long flashes at 6KHz, 2000µs after microphone sensor trigger, 36m/s airsoft pistol 6mm diameter pellet) $ sudo ./audio_shots 5 9 6000 2000 https://stamm-wilbrandt.de/en/forum...
by HermannSW
Tue Sep 03, 2019 5:06 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 40
Views: 4574

Re: Raspberry v1 camera global (external) shutter videos

I made progress, in determining the offset needed. Unlike yesterday where I used a v1 camera with manually added M12 lens mount and lens, I used this time the last v1 camera clone I received as is. I reduced N to 50 shots, and doubled frequency to 6000Hz, and captured frames like this: https://stamm...
by HermannSW
Tue Sep 03, 2019 3:00 pm
Forum: Camera board
Topic: Missing colors
Replies: 3
Views: 128

Re: Missing colors

If your camera is a NoIR camera, then read this top pinned thread:
https://www.raspberrypi.org/forums/view ... 3&t=245994

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