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by HermannSW
Tue Sep 10, 2019 4:10 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 43
Views: 5462

Re: Raspberry v1 camera global (external) shutter videos

Today's posting is on first 20000eps frame captured (exposures per second). The frame with most exposures per second sofar was 9000eps frame of airgun pellet. Because pellet length is 8mm, and distance between pellet exposure points is 10.77mm, flash PWM frequency cannot be increased much without ge...
by HermannSW
Mon Sep 09, 2019 4:32 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 43
Views: 5462

Re: Raspberry v1 camera global (external) shutter videos

Raspberry v1 camera (clone) can do global shutter capturing at DAYLIGHT! No "external" shutter needed, but better to use external shutter for better frame quality. I have seen it before with another camera. ov2640 sensor was able to do global shutter capturing of mini drone propeller at daylight: ht...
by HermannSW
Mon Sep 09, 2019 11:09 am
Forum: Camera board
Topic: raspiraw does not connect to camera
Replies: 3
Views: 205

Re: raspiraw does not connect to camera

"gpio: not found" -- you need to install wiringpi library.
Find a complete list on what you need to install in Robert's blog posting:
https://blog.robertelder.org/recording- ... pi-camera/
by HermannSW
Sun Sep 08, 2019 10:10 pm
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 48
Views: 4229

Re: pigpio C sub µs single pulse generation

I disconnected D0 from GPIO17, and connected GPIO18 to GPIO17. In one ssh console I executed this command: $ while true; do sudo ./audio_shots.freeze 20 18 2500 2510; done It took some tries, but this is first "freeze the Pi" without microphone sensor used -- still with GPIO13 connected to Mosfets: ...
by HermannSW
Sun Sep 08, 2019 9:32 pm
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 48
Views: 4229

Re: pigpio C sub µs single pulse generation

I did 9 shots after having connected logic analyzer to freeze the Pi again: https://stamm-wilbrandt.de/en/forum/microphone.9shots.png This is zoom into 9th shot for microphone sensor D0 line: https://stamm-wilbrandt.de/en/forum/microphone.9shots.zoom.png But it does not reflect the details, I export...
by HermannSW
Sun Sep 08, 2019 9:06 pm
Forum: C/C++
Topic: pigpio C sub µs single pulse generation
Replies: 48
Views: 4229

Re: pigpio C sub µs single pulse generation

Sorry, I had too much interesting new stuff to do over the weekend in the other thread, really amazing! https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=241418&p=1532876#p1532362 Now I compiled audio_shots.freeze.c, started this command and recreated Pi freeze after 5 shots (without magazine)...
by HermannSW
Sun Sep 08, 2019 4:39 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 43
Views: 5462

Re: Raspberry v1 camera global (external) shutter videos

Combining spin and two speeds investigation, I did only put one blue dot onto three pellets. I filled the magazine with 2 normal pellets, then the three pellets with a single blue dot, and finally a normal pellet. After starting raspivid_ges in one console, I started this command in another console:...
by HermannSW
Sun Sep 08, 2019 4:32 pm
Forum: Camera board
Topic: How to zoom Rpi camera v2 ?
Replies: 4
Views: 311

Re: How to zoom Rpi camera v2 ?

Please see the video in the posting I pointed to, it kept at 640x480 resolution the whole time while camera moving and zooming. So your 720p resolution will not change by using camera.zoom().
by HermannSW
Sat Sep 07, 2019 9:10 pm
Forum: Camera board
Topic: Raspberry v1 camera global (external) shutter videos
Replies: 43
Views: 5462

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: 43
Views: 5462

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: 43
Views: 5462

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: 311

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: 494

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: 48
Views: 4229

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: 4840

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: 849

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: 48
Views: 4229

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: 43
Views: 5462

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: 48
Views: 4229

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: 849

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: 135

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: 154

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: 301

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: 849

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: 261

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...

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