Go to advanced search

by ab1jx
Wed Apr 29, 2020 5:31 pm
Forum: Camera board
Topic: Shooting .raw pictures
Replies: 8
Views: 691

Re: Shooting .raw pictures

OK, I don't do Python but if you look at the Raspistill usage page (type raspistill --help) it says "-r, --raw : Add raw bayer data to jpeg metadata" which doesn't sound that useful unless you're going to write something to dig it out. The RaspiCam-Documentation.pdf says you can use raspistillyuv li...
by ab1jx
Wed Apr 29, 2020 2:23 pm
Forum: Camera board
Topic: Shooting .raw pictures
Replies: 8
Views: 691

Re: Shooting .raw pictures

Yes, it's Bayer but with ufraw, maybe other things, you can output 16-bit ppm files after the raw conversion. https://www.nikonusa.com/en/learn-and-explore/a/products-and-innovation/nikon-electronic-format-nef.html You have a much higher probability of avoiding overexposure on highlights because you...
by ab1jx
Wed Apr 29, 2020 3:59 am
Forum: Camera board
Topic: Pi Zero W with Pi Camera - FFMPEG Stream to YouTube - Stability Issues
Replies: 3
Views: 399

Re: Pi Zero W with Pi Camera - FFMPEG Stream to YouTube - Stability Issues

Before you sink a lot of time into it, be aware that the camera socket on a Zero has a very short life, like 20 insertions. This is in a PDF on the connector somewhere. It's because a complete Zero sells so cheaply I think. So prototype on a Pi then switch to a Zero at the end.
by ab1jx
Wed Apr 29, 2020 3:46 am
Forum: Camera board
Topic: Stop. Gluing. The. Camera. Lens.
Replies: 18
Views: 1077

Re: Stop. Gluing. The. Camera. Lens.

There is a focus wrench available. Google it. I bought one several years ago, don't remember where. It's a 3d printed thing, I paid I think $20 for a steel one. There's a cheaper plastic one. It works kind of like a spanner, fits into those little notches around the lens. See https://www.thingiverse...
by ab1jx
Wed Apr 29, 2020 3:21 am
Forum: Camera board
Topic: How to cut out visible light spectrum from IR camera
Replies: 5
Views: 491

Re: How to cut out visible light spectrum from IR camera

This is what you get I believe if you just buy an "IR filter" for a digital camera. I have a couple. This one https://www.bhphotovideo.com/c/product/23076-REG/Hoya_B52RM72_52mm_RM72_Infrared_Glass.html says it "Blocks Visible Light Up To 720nm". You don't need one this big (diameter) or this expensi...
by ab1jx
Wed Apr 29, 2020 3:11 am
Forum: Camera board
Topic: Shooting .raw pictures
Replies: 8
Views: 691

Re: Shooting .raw pictures

Gimp should be able to handle that I think, instead of the extension .raw use .data. You'll get prompted for the height and width when you're opening. Specify a width and watch, the preview should suddenly look right. It just needs to know how much data belongs to each line of pixels, the height it ...
by ab1jx
Mon Apr 27, 2020 5:35 pm
Forum: General discussion
Topic: Anybody used a Pi's GPIO bus for resetting laptop "smart batteries"?
Replies: 3
Views: 1408

Re: Anybody used a Pi's GPIO bus for resetting laptop "smart batteries"?

Nope, I still haven't gotten the Dell batteries opened but I think I found the secret at https://www.insidemylaptop.com/open-take-apart-dell-laptop-battery/ I have a box of 10 new cells I got on Aliexpress. These days my old laptops are mostly home to a couple 1 TB hard drives. I power them up to gr...
by ab1jx
Sun Apr 26, 2020 3:23 pm
Forum: General discussion
Topic: Pi setup using phone only
Replies: 5
Views: 381

Re: Pi setup using phone only

Set up Wireless Hotspot on your Smartphone and then follow the tutorial for SSH: https://www.raspberrypi.org/documentation/remote-access/ I actually tried that before posting. Naturally it didn't work (otherwise i wouldn't have posted all that). I tried again, and it worked. Must've half-assed it t...
by ab1jx
Sun Apr 26, 2020 1:58 pm
Forum: Troubleshooting
Topic: slow / no ssh on RPi0
Replies: 6
Views: 312

Re: slow / no ssh on RPi0

How are you figuring out what IP address to use? Mostly machines get reassigned the same ones but there's no guarantee. A machine can request a certain address but you have to muck around in each /etc/dhcp/dhclient.conf and add it. Try this sometime: ps ax | grep sshd 538 ? Ss 0:00 /usr/sbin/sshd -D...
by ab1jx
Sun Apr 26, 2020 1:54 am
Forum: Troubleshooting
Topic: slow / no ssh on RPi0
Replies: 6
Views: 312

Re: slow / no ssh on RPi0

When was the last time you rebooted your router? And/or your wifi AP. 3 weeks seems odd, is this with doing apt-get updates and upgrades or without? Some upgrade could have done it, that happens sometimes. Or maybe a lack of them. Yeah, I think enabling ssh in raspi-config just makes sshd start, I a...
by ab1jx
Sat Apr 25, 2020 9:05 pm
Forum: Troubleshooting
Topic: slow / no ssh on RPi0
Replies: 6
Views: 312

Re: slow / no ssh on RPi0

Try ping sometime, that should be faster. And after ping works sometimes ssh works sooner. It has to do with the routing tables I think, I've had that problem a year or so ago. If you've made manual entries to your hosts files that can backfire if you don't do it right. When my wifi AP lost its inte...
by ab1jx
Sat Apr 25, 2020 3:30 pm
Forum: General discussion
Topic: SafePaths on a Pi/Zero?
Replies: 0
Views: 139

SafePaths on a Pi/Zero?

SafePaths AKA PrivateKit is an MIT covid contact tracer under development. Mostly for the US but not limited to that. The first priority is privacy. Each phone logs its location for 2-4 weeks but that never leaves the phone unless you send it. Central databases with feeds from hospitals send out inf...
by ab1jx
Sat Apr 25, 2020 2:13 pm
Forum: General discussion
Topic: Pi setup using phone only
Replies: 5
Views: 381

Re: Pi setup using phone only

One problem with phones is that they don't last that long. And they're expensive. And tiny. I have 4, 2 still work. It is possible to set up Debian (or Ubuntu?) on a phone if it's Android since Android uses a Linux kernel. I had 2 set up that way, but about 70% of the CPU cycles go into making Andro...
by ab1jx
Sat Apr 11, 2020 11:00 pm
Forum: Camera board
Topic: Is anybody using a NOIR camera to spot fever/covid?
Replies: 6
Views: 2986

Re: Is anybody using a NOIR camera to spot fever/covid?

OK, that's out. How about using a Pi or a ZeroW to monitor the proposed Apple/Google Bluetooth covid tracking? (In the US) https://www.theverge.com/2020/4/10/21216715/apple-google-coronavirus-covid-19-contact-tracing-app-details-use It would be useful if this wasn't locked down to those 2 companies,...
by ab1jx
Sat Apr 11, 2020 3:52 pm
Forum: Camera board
Topic: Is anybody using a NOIR camera to spot fever/covid?
Replies: 6
Views: 2986

Re: Is anybody using a NOIR camera to spot fever/covid?

OK, I looked up the original article
https://www.reuters.com/article/us-heal ... SKCN21R2SF

The promise of a fast, non-contact way of checking temperatures is what it's all about. And there are people selling these things. But drastically different wavelengths.
by ab1jx
Sat Apr 11, 2020 2:53 pm
Forum: Camera board
Topic: Is anybody using a NOIR camera to spot fever/covid?
Replies: 6
Views: 2986

Re: Is anybody using a NOIR camera to spot fever/covid?

OK, by a page at Element14 it sees 700 - 1000 nm, by this Wikipedia page you want 1000 nm and longer. https://en.wikipedia.org/wiki/Thermographic_camera So it's close. And from another Wikipedia page "Humans at normal body temperature radiate chiefly at wavelengths around 10 μm (micrometers)" [AKA 1...
by ab1jx
Sat Apr 11, 2020 1:06 pm
Forum: Camera board
Topic: Is anybody using a NOIR camera to spot fever/covid?
Replies: 6
Views: 2986

Is anybody using a NOIR camera to spot fever/covid?

The need for doing this will linger well past the levelling-off point I think. Take a NOIR camera and add an optical filter to block most visible light. It then can work similarly to thermal imaging cameras used in firefighting, or the cameras used to spot heat escaping through gaps in household ins...
by ab1jx
Mon Sep 02, 2019 2:37 am
Forum: General discussion
Topic: Be careful with Pi Zero and CSI slot
Replies: 40
Views: 15042

Re: Be careful with Pi Zero and CSI slot

If you look at the Molex PDF you can see the problem: Durability (mating cycles max) 20 That's from http://www.molex.com/webdocs/datasheets/pdf/en-us/0545482271_FFC_FPC_CONNECTORS.pdf A DIP or a DB25 would be more sturdy. That flexboard cable can't be flexed many times before the foil breaks either.
by ab1jx
Tue May 07, 2019 12:05 am
Forum: Troubleshooting
Topic: Have you looked at rtl_power?
Replies: 2
Views: 1493

Re: Have you looked at rtl_power?

Take a look at https://sourceforge.net/p/fmplot/ I just wrote it for plotting the US FM broadcast band to find nrsc5 (AKA HD FM) stations. They're about twice as wide as traditional analog FM stations so they're fairly visible. It uses rtl_power to scan, formats the output and feeds ti to Gnuplot to...
by ab1jx
Sun May 05, 2019 3:34 am
Forum: General discussion
Topic: So, tried qt-dab yet?
Replies: 5
Views: 1059

Re: So, tried qt-dab yet?

I listened a few minutes tonight and it was cutting out when I used the GUI, didn't happen with the bare command line program. The basic program is in C, the GUI is in Python. Too much of a performance penalty I guess. The GUI doesn't accomplish much in my case, the only HD station I've found isn't ...
by ab1jx
Fri May 03, 2019 3:18 pm
Forum: General discussion
Topic: So, tried qt-dab yet?
Replies: 5
Views: 1059

Re: So, tried qt-dab yet?

There is a GUI for it, and supposedly an API for making your own. See https://github.com/cmnybo/nrsc5-gui What it shows depends on what the stations put on the air, it can do traffic and weather maps, album covers, but not here. I used fmfool http://www.fmfool.com/index.php?option=com_wrapper&Itemid...
by ab1jx
Thu May 02, 2019 11:28 pm
Forum: General discussion
Topic: So, tried qt-dab yet?
Replies: 5
Views: 1059

Re: So, tried qt-dab yet?

So you can record to a wav file for an hour or so then chop it up like this in Audacity. You can see where the song starts and ends. It's clunky but it works. chopping.jpg This is a really old local rock station that's been around for 45 years or so, same frequency, they just added the digital stuff...
by ab1jx
Thu May 02, 2019 5:55 pm
Forum: General discussion
Topic: So, tried qt-dab yet?
Replies: 5
Views: 1059

Re: So, tried qt-dab yet?

Yeah, OK, I got that working, just listened to something by Metalica. Hearing commercials though. It's (I guess) https://en.wikipedia.org/wiki/HD_Radio This has no GUI, there's an API to add one. It works strictly like rtl_fm where you type a frequency and program number. There's no easy way to brow...
by ab1jx
Wed May 01, 2019 2:58 am
Forum: General discussion
Topic: So, tried qt-dab yet?
Replies: 5
Views: 1059

Re: So, tried qt-dab yet?

OK , there is no DAB in the US but it should work elsewhere. There was never frequency allocation for it here because there's too much other stuff. nodab.png If it works it should look more like the official screenshot: https://github.com/JvanKatwijk/qt-dab/blob/master/screenshot_qt-dab.png I'm tryi...
by ab1jx
Sat Apr 27, 2019 10:25 pm
Forum: General discussion
Topic: So, tried qt-dab yet?
Replies: 5
Views: 1059

So, tried qt-dab yet?

I just got a new rtl2832 dongle in the mail and it says DAB among other things on it so I thought I'd give DAB a try. My first search took me to https://wiki.opendigitalradio.org/DAB_reception and then I went to https://github.com/JvanKatwijk/qt-dab After checking the debs with Synaptic of course, i...

Go to advanced search