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by gtoal
Sat Feb 23, 2019 3:17 am
Forum: Automation, sensing and robotics
Topic: Stereo camera with CM3 inside for OpenCV learners, drones and robotics
Replies: 26
Views: 5727

Re: Stereo camera with CM3 inside for OpenCV learners, drones and robotics

Two comments from me. 1) I jumped on this as soon as I saw it because I'm a stereo photographer from way back and thought this was going to be hardware-synchronised frame grabbing, especially for video - I was a little disappointed when I read that the cameras are shot sequentially with a 1ms delay ...
by gtoal
Fri Jul 13, 2018 3:09 am
Forum: C/C++
Topic: How to get most precise timer or sleep function on Raspberry
Replies: 13
Views: 8539

Re: How to get most precise timer or sleep function on Raspberry

given the recent announcement of the RT kernel branch ( https://www.raspberrypi.org/forums/viewtopic.php?f=117&t=206747 ), the answers here might need to be updated, for instance the use of nanosleep rather than usleep See https://www.raspberrypi.org/forums/viewtopic.php?p=384910 https://elinux.org/...
by gtoal
Thu Jun 28, 2018 10:01 pm
Forum: HATs and other add-ons
Topic: How to sense a 5v input with GPIO
Replies: 18
Views: 46968

Re: How to sense a 5v input with GPIO

pcmanbob wrote:
Tue Jun 26, 2018 10:54 am
You can calculate the current flowing through the resistors by simply using ohm's law were current = voltage / resistance , I =V/R
Groan! The embarrassment of realising that E=IR was the only factor involved :-/
by gtoal
Tue Jun 26, 2018 1:40 am
Forum: HATs and other add-ons
Topic: How to sense a 5v input with GPIO
Replies: 18
Views: 46968

Re: How to sense a 5v input with GPIO

I have a very similar problem but the issue I want to check with you is how much current is dissipated across the resistors - I have a system that is powered by the 5V bus of a Vectrex computer. Attached to the Vectrex is a smart cartridge (ARM powered but not pi-related) which is powered by the Vec...
by gtoal
Thu Apr 12, 2018 10:46 pm
Forum: Bare metal, Assembly language
Topic: Is there a bare metal arduino-like environment?
Replies: 1
Views: 525

Is there a bare metal arduino-like environment?

I know there is a system available to compile and run arduino-like sketches on the Pi under Raspbian, but is it possible to run similar sketches on the Pi without a multitasking O/S, just the sketch and some boot code and appropriate arduino-like libraries pre-linked? (Just asking out of interest, d...
by gtoal
Sun Feb 25, 2018 11:04 pm
Forum: Camera board
Topic: Alternatives or replacements for camera flex cable?
Replies: 149
Views: 129107

Re: Alternatives or replacements for camera flex cable?

If US -> DE shipping is too expensive, how about these? - https://www.ebay.com/itm/15Pin-to-15Pin-ZIF-1-0mm-Pitch-FFC-Cable-Extension-Connector-Adapter-Brand-New-/122454866623 and similar - is shipping from China to Europe usually free like it is from China to USA? (courtesy of the Universal Postal ...
by gtoal
Fri Feb 23, 2018 7:14 pm
Forum: Camera board
Topic: Alternatives or replacements for camera flex cable?
Replies: 149
Views: 129107

Re: Alternatives or replacements for camera flex cable?

There are a few of these extender boards around - for example, https://www.adafruit.com/product/3671
by gtoal
Thu Feb 08, 2018 5:53 pm
Forum: General programming discussion
Topic: British-made programming language
Replies: 54
Views: 12628

Re: British-made programming language

Paul Webster, Wow, it's a long time since I heard anything from a former Coral-66 programmer. I did a couple of years of Coral 66 back in the early 1980's. For Marconi Radar. Yes, Coral was similar enough to Algol to be picked up quickly. I had never heard of it before starting at Marconi Radar. Th...
by gtoal
Tue Feb 06, 2018 7:43 pm
Forum: General programming discussion
Topic: British-made programming language
Replies: 54
Views: 12628

Re: British-made programming language

Well, I was reading through this thread and thinking I'ld like to add some info, but had decided not to when I saw the 2012 date - but since some brave soul has already resurrected it... here goes... You've got the main ones. Pleased to see that Gordon mentioned Imp - though to clarify the primary l...
by gtoal
Mon Sep 11, 2017 7:48 am
Forum: General discussion
Topic: Be careful with Pi Zero and CSI slot
Replies: 39
Views: 9564

Re: Be careful with Pi Zero and CSI slot

I now have broken CSI clamps on 3 of 6 pi zeros. After the first one I was extra careful but it still happened. I consider it a design flaw. I've used extremely sticky tape to hold one in place over the broken connector but the depth of insertion is so shallow that even a little amount of give to th...
by gtoal
Sun Aug 06, 2017 11:37 pm
Forum: General discussion
Topic: keeping the temp low without fans?
Replies: 14
Views: 2277

Re: keeping the temp low without fans?

OutoftheBOTS wrote:
Sun Aug 06, 2017 9:42 pm
cut a little hole in the hat for a heat sink to stick out. The bottom line is that you have the let the heat escape so that it doesn't build up
I think I've solved the fan problem :-) (That probably *would* pass as normal in this part of the world :-/ )
by gtoal
Sun Aug 06, 2017 11:33 pm
Forum: General discussion
Topic: keeping the temp low without fans?
Replies: 14
Views: 2277

Re: keeping the temp low without fans?

How are you protecting the Pi from ESD? I just lost a new Pi0W to static (as far as the forum can conclude) Interesting, had not seen those threads. I just bought my second Pi Zero W a week or so back, and after working once, the wifi stopped working permanently. I didn't handle it roughly at all b...
by gtoal
Sun Aug 06, 2017 9:33 pm
Forum: General discussion
Topic: keeping the temp low without fans?
Replies: 14
Views: 2277

Re: keeping the temp low without fans?

Thanks for all your comments and suggestions. I'll look into seeing if it's possible to turn off the speed governor as suggested and lock it down at the lowest speed, and see how much difference that makes. Heatsinks etc aren't a option - there is literally no room for *anything* extra, and sticking...
by gtoal
Sun Aug 06, 2017 5:51 am
Forum: General discussion
Topic: keeping the temp low without fans?
Replies: 14
Views: 2277

keeping the temp low without fans?

I've just built a hat for a pi zero w. No, I don't mean an add-on card, I mean the thing you stick on your head :-) It contains a hidden picam that want to continuously record my day with, plus do anything else I might want an on-head personal assistant to do :-) The trouble is, the pi is right next...
by gtoal
Sat Jul 22, 2017 10:13 pm
Forum: AIY Projects
Topic: Google Assistant does not play music and some other commands
Replies: 10
Views: 19849

Re: Google Assistant does not play music and some other comm

As far as I can tell, the inability to play music appears to be a side-effect of not being able to select the raspberry-pi-based assistant device in the Google Home app. Which means it is impossible to set the default music source for the device - even though I suspect it could play the music if onl...
by gtoal
Thu Jul 13, 2017 1:42 pm
Forum: Raspbian
Topic: dpkg returned an error code (1)
Replies: 5
Views: 3904

Re: dpkg returned an error code (1)

Solved! pi@bedside:~/src/listener-2.2 08:36 $ dpkg --get-selections|fgrep ffm ffmpeg install pi@bedside:~/src/listener-2.2 08:36 $ sudo dpkg --remove ffmpeg (Reading database ... 124393 files and directories currently installed.) Removing ffmpeg (3.1.1-1) ... dpkg: warning: while removing ffmpeg, di...
by gtoal
Thu Jul 13, 2017 4:43 am
Forum: Raspbian
Topic: dpkg returned an error code (1)
Replies: 5
Views: 3904

Re: dpkg returned an error code (1)

Same here, while trying to install Google Assistant as per https://developers.google.com/assistant/sdk/prototype/getting-started-pi-python/run-sample I tried removing ffmpeg by these commands but neither worked: sudo apt-get remove ffmpeg sudo apt-get remove --purge ffmpeg I also tried temporarily r...
by gtoal
Wed Jul 05, 2017 5:24 pm
Forum: Troubleshooting
Topic: can't install munin - error processing archive /var/cache/ap
Replies: 2
Views: 566

Re: can't install munin - error processing archive /var/cach

Try sudo rm /var/cache/apt/archives/libsigsegv2_2.10-4_armhf.deb Thanks - that's doing the trick! I have to confess most of my unix experience is from the days when you had to fetch a tar file and build stuff yourself from source. I don't really have much experience of these new-fangled package man...
by gtoal
Wed Jul 05, 2017 5:04 pm
Forum: Troubleshooting
Topic: can't install munin - error processing archive /var/cache/ap
Replies: 2
Views: 566

can't install munin - error processing archive /var/cache/ap

did an apt-get update first... apt-get install munin causes this error: 0 upgraded, 45 newly installed, 0 to remove and 319 not upgraded. Need to get 0 B/5,338 kB of archives. After this operation, 24.0 MB of additional disk space will be used. Do you want to continue? [Y/n] Extracting templates fro...
by gtoal
Tue Jun 27, 2017 1:11 am
Forum: Troubleshooting
Topic: Reliable USB ethernet for Raspberry PI
Replies: 5
Views: 1055

Re: Reliable USB ethernet for Raspberry PI

https://www.raspberrypi.org/forums/viewtopic.php?f=45&t=186555 Thanks - wish I had seen this before ordering that adapter with some random unknown chipset! :-) I've now also ordered one of these cheap ones from eBay ($3.85): http://www.ebay.com/itm/282328781990 and a slightly more expensive one on ...
by gtoal
Mon Jun 26, 2017 2:08 am
Forum: Troubleshooting
Topic: Reliable USB ethernet for Raspberry PI
Replies: 5
Views: 1055

Re: Reliable USB ethernet for Raspberry PI

I've used this on Model A+'s http://www.banggood.com/USB3_0-Gigabit-Ethernet-Adapter-RJ45-Network-Card-101001000Mbps-p-959605.html if you use a micro to normal shim you can use it on a PI0 I have about 20 pi's online at home. Two of them crash every few days with a kernel "Oops". It's the same two ...
by gtoal
Tue Jun 20, 2017 3:46 pm
Forum: HATs and other add-ons
Topic: RPi + PS3Eye getting Sound-microphone
Replies: 16
Views: 15024

Re: PS3 Eye works again!

Happy to report that if you do sudo apt-get update && sudo apt-get upgrade as of today on your RPi running Raspbian 8.0 (jessie), and then reboot you will get kernel 4.9.24-v7+ #993 SMP Wed Apr 26 18:01:23 BST 2017 and this DOES WORK with the PS3 Eye audio, both with Audacity and a simple command l...
by gtoal
Sat Jun 03, 2017 4:51 pm
Forum: Camera board
Topic: motion: grey segments in avi (unable to open video device)
Replies: 0
Views: 685

motion: grey segments in avi (unable to open video device)

I've installed motion and it seems to work - it captures single frames OK when it detects motion, and I can watch the camera via web streaming just fine, but the saved avi files look like this: http://gtoal.com/motion/53-20170603082020.avi - a few frames are present but interspersed with grey frames...
by gtoal
Wed Mar 29, 2017 6:04 pm
Forum: General discussion
Topic: Unable to Install using apt-get
Replies: 39
Views: 118494

Re: Unable to Install using apt-get

I've been getting this problem off and on, and usually apt-get update fixes it, but recently I've had some packages that just will not install, so I finally got out the trusty sniffer and looked into it closely to find the underlying problem. After redirection by mirrordirector.raspbian.org, my requ...
by gtoal
Wed Mar 29, 2017 5:53 am
Forum: Graphics, sound and multimedia
Topic: How to use my Pi as contributor for Broadcastify.com
Replies: 3
Views: 1015

Re: How to use my Pi as contributor for Broadcastify.com

fruitoftheloom wrote:
some_evil wrote:And another question, is the pi capable of using a stereo 3.5mm audio jack as a line in (mic)???
The Raspberry Pi has no Audio Input built in, you need to use a USB Sound card or a GPIO AUdio HAT Card ;)
He could use an SDR to receive the audio from radio and also do frequency scanning too...

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