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by acawley
Tue Feb 18, 2020 4:46 pm
Forum: General programming discussion
Topic: Securing SD card Image by encrypting in raspberry pi 3
Replies: 17
Views: 37245

Re: Securing SD card Image by encrypting in raspberry pi 3

Apologies! I did indeed miss that link it seems, thank you for bringing it to my attention, I will certainly be giving it a read and a go myself when I have time.

Anyone out there given it a go? What were your experiences?
by acawley
Tue Feb 18, 2020 4:30 pm
Forum: General programming discussion
Topic: Securing SD card Image by encrypting in raspberry pi 3
Replies: 17
Views: 37245

Re: Securing SD card Image by encrypting in raspberry pi 3

I'm confused by the negative responses on this, as though it is impossible to encrypt a device. Would it not be possible to implement some form of full disk encryption on the SD card in a way that it prompts the user for a decryption key on-boot. So the user holds the secret key (a good password in ...
by acawley
Thu Jan 30, 2020 7:40 pm
Forum: Automation, sensing and robotics
Topic: PIR false positives
Replies: 8
Views: 4990

Re: PIR false positives

I wanted to pitch in with my fix which I haven't heard anyone else mention yet: So I had a home-built alarm system that used a PIR sensor (cheap HC-SR501), worked reliably for a couple of months with no false positives, then I had problems. I spent days troubleshooting and was pulling my hair out in...
by acawley
Thu Jan 30, 2020 7:40 pm
Forum: Automation, sensing and robotics
Topic: weird problem: PIR sensor positive on wifi activity
Replies: 20
Views: 10755

Re: weird problem: PIR sensor positive on wifi activity

I wanted to pitch in with my fix which I haven't heard anyone else mention yet: So I had a home-built alarm system that used a PIR sensor (cheap HC-SR501), worked reliably for a couple of months with no false positives, then I had problems. I spent days troubleshooting and was pulling my hair out in...
by acawley
Tue Nov 05, 2019 5:32 pm
Forum: Automation, sensing and robotics
Topic: Triggering an Alarm with a Raspberry Pi
Replies: 11
Views: 2075

Re: Triggering an Alarm with a Raspberry Pi

I've just purchased this cheap DC relay here: https://www.ebay.co.uk/itm/182307855649
Although I'm still quite new to working with relays I'm quite confident I should be able to make this one work in the setup I want.

I will keep you posted!
by acawley
Tue Nov 05, 2019 5:22 pm
Forum: Automation, sensing and robotics
Topic: Triggering an Alarm with a Raspberry Pi
Replies: 11
Views: 2075

Re: Triggering an Alarm with a Raspberry Pi

In the UK this is a maximum of 20 minutes, although many modern alarm bells have a built in limit of 15 minutes. I wasn't aware of that so thank you for letting me know. By chance I had already coded in a 5 minute timer into the software. In conjunction with the siren going off this Pi will actuall...
by acawley
Fri Nov 01, 2019 4:34 pm
Forum: Automation, sensing and robotics
Topic: Triggering an Alarm with a Raspberry Pi
Replies: 11
Views: 2075

Re: Triggering an Alarm with a Raspberry Pi

Perhaps the Sonoff wont be just the tool for this project - being that I've just noticed it wants a minimum of 90v AC and the siren I will be working with will be 12v DC. I'll cook-up some other plan for the DC relay to be controlled by the Pi I'm sure.
by acawley
Fri Nov 01, 2019 3:27 pm
Forum: Automation, sensing and robotics
Topic: Triggering an Alarm with a Raspberry Pi
Replies: 11
Views: 2075

Re: Triggering an Alarm with a Raspberry Pi

Well thanks to pcmanbob's suggestion I checked our eBay and I couldn't believe the range of different 12v sirens you could get, simply supply power and woof! Off they go. So I think I might try going that route. I've just order this one: https://www.ebay.co.uk/itm/DC-12V-Loud-Wired-Mini-Indoor-Acces...
by acawley
Fri Nov 01, 2019 3:07 pm
Forum: Automation, sensing and robotics
Topic: Triggering an Alarm with a Raspberry Pi
Replies: 11
Views: 2075

Re: Triggering an Alarm with a Raspberry Pi

These are handy for inexpensively controlling powered devices via the PIi's GPIOs... https://cdn.shopify.com/s/files/1/2185/4851/products/iot2_1024x1024@2x.jpg?v=1500075827 Interesting! I've not seen one of those before. But you have just made me remember that I actually have a Sonoff Basic WiFi Sm...
by acawley
Fri Nov 01, 2019 3:03 pm
Forum: Automation, sensing and robotics
Topic: Triggering an Alarm with a Raspberry Pi
Replies: 11
Views: 2075

Re: Triggering an Alarm with a Raspberry Pi

You might do better to search you favourite on line sales sites for a simple siren, much cheaper but still likely to 12v DC powered. I don't mind supplying the alarm / speaker with its own power-supply, I could give it 12v or 5v easily with a seperate source. Thank you for the idea though I will ch...
by acawley
Thu Oct 31, 2019 9:27 pm
Forum: Automation, sensing and robotics
Topic: Triggering an Alarm with a Raspberry Pi
Replies: 11
Views: 2075

Triggering an Alarm with a Raspberry Pi

I'm trying to learn how to sound an alarm (fire-alarm ideally) as part of a home-brew security alarm system for my shed. I am not trying to build a fire alarm , but instead a motion sensing security system. No camera , just motion sensing and then sounding an alarm. I feel like I'm most of the way t...
by acawley
Sun Nov 18, 2018 8:38 pm
Forum: Advanced users
Topic: Encryption for SSH Jump Box
Replies: 4
Views: 1695

Re: Encryption for SSH Jump Box

-J or ProxyJump option Interesting, I didn't know about this option, I will have to do some research on that, thank you. Going by my knowledge so far I thought that my SSH Jumpbox (RPi0) would have had to have held all the keys in order to connect to the remote servers. I have used a SSH gateway/ju...
by acawley
Sat Nov 17, 2018 6:36 pm
Forum: Advanced users
Topic: Encryption for SSH Jump Box
Replies: 4
Views: 1695

Re: Encryption for SSH Jump Box

Thanks for your input, I will checkout LUKS further. I'm not familiar with AppArmor, but I'm not intending to install or use other common applications on the RPi, it would just be used as a SSH gateway. Apologies if I have misunderstood you. My idea is that I would carry a Pi Zero with me that I cou...
by acawley
Sat Nov 17, 2018 5:20 pm
Forum: Advanced users
Topic: Encryption for SSH Jump Box
Replies: 4
Views: 1695

Encryption for SSH Jump Box

This is more a question about Encryption on Raspbian than anything.... What would be the best encryption to use on Rasbian to encrypt a home folder ? Hopefully something which is relatively easy to use and setup. With Raspberry Pi Zero's being such a great small portable computer I came up with an i...
by acawley
Wed Jul 25, 2018 7:48 pm
Forum: Other projects
Topic: Remote Puppy Video & Audio Monitor
Replies: 3
Views: 1959

Re: Remote Puppy Video & Audio Monitor

I just wanted to thank you for telling me about motionEyeOS - https://github.com/ccrisan/motioneyeos/wiki It was perfect for remotely monitoring our new puppy overnight. What a superb way to run a remote camera and stream the footage live! I combined it with a Pi NoIR Camera which see's infrared (IR...
by acawley
Tue Jul 17, 2018 6:21 pm
Forum: Other projects
Topic: Remote Puppy Video & Audio Monitor
Replies: 3
Views: 1959

Re: Remote Puppy Video & Audio Monitor

Thank you Steven, I'm going to give this a try now!
by acawley
Mon Jul 16, 2018 8:03 pm
Forum: Other projects
Topic: Remote Puppy Video & Audio Monitor
Replies: 3
Views: 1959

Remote Puppy Video & Audio Monitor

I'm after some advice, we're getting our first puppy in one week and I want to build a puppy-monitoring station (like a baby monitor) that we may only use for a few weeks. I already have numerous different Pi's spare and a NoIR Camera module. I have a new 24" HDMI monitor with built in speakers...
by acawley
Sat Jun 23, 2018 9:51 pm
Forum: Graphics, sound and multimedia
Topic: Rotating a photo only slightly
Replies: 11
Views: 1810

Re: Rotating a photo only slightly

Just achieved it! ...
testbild-worked.png
testbild-worked.png (2.43 KiB) Viewed 1691 times

Code: Select all

pi@SolarPi:~ $ ssocr -D crop 585 155 225 115 -t 58 -d -1 1080.jpg
12.6
:D
by acawley
Sat Jun 23, 2018 9:38 pm
Forum: Graphics, sound and multimedia
Topic: Rotating a photo only slightly
Replies: 11
Views: 1810

Re: Rotating a photo only slightly

You can use Image Magick to rotate an image. mogrify or convert will take a rotation angle in degrees. http://www.minihowtos.net/imagemagick-rotate-image http://www.imagemagick.org/Usage/distorts/#rotate_methods Great suggestion - thank you! I already had Image Magick installed as I was using it to...
by acawley
Sat Jun 23, 2018 6:37 pm
Forum: Graphics, sound and multimedia
Topic: Rotating a photo only slightly
Replies: 11
Views: 1810

Re: Rotating a photo only slightly

I have ssocr installed and working with its test example on the shell of the Pi which is great! But could you help me out with the correct example usage? I'm trying to reference the manual but not sure if I should be using something like: ssocr -T rotate 354 voltage.jpg I have a suspicion that -T ma...
by acawley
Sat Jun 23, 2018 6:10 pm
Forum: Graphics, sound and multimedia
Topic: Rotating a photo only slightly
Replies: 11
Views: 1810

Re: Rotating a photo only slightly

Thanks for the input gordon and scruss! I could straighten the rig but not immediately (it is somewhat remote). I can also modify the casing to reduce reflections, so duly noted. I purposely lowered the size of the image for automatic upload to my page to minimise on bandwidth and speed things up, b...
by acawley
Sat Jun 23, 2018 12:22 pm
Forum: Graphics, sound and multimedia
Topic: Rotating a photo only slightly
Replies: 11
Views: 1810

Re: Rotating a photo only slightly

Thanks for the suggestion Dougie, but I'm looking to achieve this in an automated fashion on the shell of the Pi if possible, I'm comfortable creating a bash script for that providing I know the right tool to use - but this is where I am struggling. I made this script: https://github.com/ashleycawle...
by acawley
Sat Jun 23, 2018 11:26 am
Forum: Graphics, sound and multimedia
Topic: Rotating a photo only slightly
Replies: 11
Views: 1810

Rotating a photo only slightly

Is it possible to rotate a photo on the shell of a Raspberry Pi but only slight measures or degrees? For example if I had this image which is taken by a remote camera: voltage.jpg And I wanted the 12.8v value to be perfectly horizontal through rotating the image only slightly, I don't mind about cro...
by acawley
Tue Aug 08, 2017 7:39 pm
Forum: Networking and servers
Topic: Raspberry Pi Command & Control
Replies: 1
Views: 967

Re: Raspberry Pi Command & Control

I should add - I do have access to a server on the public web of which I am willing to open-up a custom port on, presumably this kind of system will be required to act as the central server that all the Pi's chime in to and that I could login to in order to issue commands.
by acawley
Tue Aug 08, 2017 6:48 pm
Forum: Networking and servers
Topic: Raspberry Pi Command & Control
Replies: 1
Views: 967

Raspberry Pi Command & Control

I'm familiar with controlling numerous Pi's via the terminal, using key-based SSH auth etc. however I have a question about a command and control idea. Here's the scenario: Lets say I have 5 different raspberry pi's online 24/7 spread across 3 different LAN's in 3 different locations. For whatever r...

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