How to use a Raspberry PI to chart ambient temperature vs outside temperature. Source code and schematics below.
Full article here:
Raspberry PI: Charting Ambient vs Outside Temperature (WhiskeyTangoHotel.Com)
How to use a Raspberry PI to chart ambient temperature vs outside temperature. Source code and schematics below.
Full article here:
Raspberry PI: Charting Ambient vs Outside Temperature (WhiskeyTangoHotel.Com)
We don’t know (though we’d happily accept a device for review if anyone at Asus happens to read this), but it is quite possibly the most easily upgradeable PC we have ever come across, as this video shows:
YouTube link: ASUS VivoPC Overview
This is the only full review we could find. The audio track is in Italian, but you can turn on English subtitles from the CC button in the player (that should appear once you start the video):
YouTube link: Recensione ASUS VivoPC – Review
From what we’re seeing here, it looks like this is a unit to keep an eye on, since it seems to play video pretty smoothly under both Windows and Linux. Just keep in mind that you may want to add or upgrade the memory if you plan to use this for serious computing, but I don’t think you’ll see too many systems that make that an easier process.
Note that this is the lowest-end unit of the VivoPC series, but there are two higher-end models that come in black cases and have upgraded hardware, naturally at a higher price.
Here’s a link to the article that tipped us off to this device:
Asus VivoPC mini-desktop now available for $320 and up
Running watch < command > will by default keep repeating that command every two seconds. This is good for seeing the progress of a running process, viewing memory or disk usage, or checking various things from /proc. Here are some quick examples:
Full article here:
Repeat a Command Every Few Seconds with watch (scottlinux.com)
Have you ever been confronted with the task of looking for a particular string or pattern in a file, yet have no idea where to start looking? Well then, here is grep to the rescue!
Full article here:
12 Practical Examples of Linux grep Command (Tecmint)
NOTE: Redo Rescue: Backup and Recovery was formerly known as Redo Backup. This article has been updated to show the new name.
If you are replacing an older hard drive with a newer one, possibly with more capacity, you may wonder if there is a way to do it without having to reinstall everything. The answer is often “yes”. There are many ways to do it — some are free and some cost money — but one great solution that happen to be free is to use Redo Rescue: Backup and Recovery, possibly followed by GPartEd Live. In fact, even if you aren’t planning on replacing a drive, it’s probably a good idea to back up your drives using Redo Rescue periodically, just in case a drive unexpectedly fails. If that happens you can restore from your last backup and you are back in business.
The nice thing about both Redo Rescue and GPartEd Live is that they have nice graphical users interfaces. Redo Rescue is very easy and intuitive, while GPartEd live is a only bit less so. For example, to move a partition within a drive you may need to use a click and drag operation, but that’s not explained on the screen. So, your favorite search engine may be your friend.
Here are some articles that explain how to use Redo Rescue:
Redo Backup and Recovery Tool to Backup and Restore Linux Systems (TecMint)
How To Use Redo Backup And Recovery In Windows 10 (Into Windows)
Redo Rescue Backup and Recovery Live System Gets NFS Share Support, SSH Server (9to5Linux)
Also you can search on YouTube for videos about Redo Rescue: Backup and Recovery.
If you are moving your system to a larger hard drive, a simple restore will only utilize as much of the drive as was used on the original drive size. What you can do is use GPartEd Live, another free tool, to grow your primary partition to occupy the remaining unused space. Before you can do that, you may need to move the existing swap partition to the end of the allocated space. What you need to do depends to some degree on the operating system in use on the drive you are moving, so you may need to do some searching to get instructions that apply to your particular situation.
Here are a couple of links about GPartEd that may help Linux users:
Expanding a Linux disk with gparted (and getting swap out of the way) (mwpreston.net)
How to move a partition to the end in gparted? (Super User)
And one for Windows users:
Resizing and Adding Partitions using GParted Live (bleepingcomputer.com)
Perhaps you have noticed that they don’t make monitor power switches the way they used to – in the past they were a large button prominently featured on the front of the monitor, but on newer models they tend to be small and harder to locate, and sometimes difficult to press. But since LED monitors draw very little power in sleep state, many people simply go into the Energy Saver settings, and set the Display Sleep value to something relatively low. But for some users, that’s an imperfect solution, because if you set it too low it might cut out on you whenever you take a brief pause from whatever you’re doing. On the other hand, if you set it too high, it might display an image when you don’t really want it to.
Another solution for OS X users is to use Hot Corners, one of which will put the display to sleep instantly. But some users hate Hot Corners, because it is much too easy to inadvertently activate one. Fortunately, for those users there is another solution, and it is found in a program called Sleep Display. While the description of Sleep Display might lead you to believe that the last supported version of OS X was Snow Leopard, we can attest to the fact that it works in Lion (though you need to press a key, such as the shift key, to wake up the display – moving the mouse won’t always do it), and there’s probably no reason it wouldn’t work Mavericks. All you do is click on the apps’s icon and the display goes to sleep. In case you wonder how it works, it’s probably just an updated version of this.
The only thing we didn’t like about Sleep Display is that it had a generic application icon, but since changing icons in OS X is easy we just created a new one in a graphics program and used the free lite version of Img2icns to convert it to proper OS X icons. Unfortunately, we can’t share it with you because it includes an image of a copyrighted cartoon cat sleeping on a pillow (which we placed in front of the image of a monitor screen, so the sleeping cat blocks the view of the display, just as a real cat might do), and even though the image we started with can be easily located using a Google image search, we don’t have the deep pockets of Google and we’d rather not get sued. It’s kind of sad that even a mashed-up icon might be lawyer bait these days, but such are the times we live in.
In case you have the opposite problem, and your display goes to sleep even when you don’t want it to, just go into the Energy Saver settings and set the Display Sleep value to Never (or a high value, such as 3 hours, if that works for you). That will stop OS X from putting the display to sleep after a short fixed delay, so it will never put the display to sleep when you don’t want it to, but you can still put it to sleep instantly any time you like using the Sleep Display app.
And just to avoid confusion, we are talking about putting the display to sleep here, not the entire computer. That feature is sometimes called “hibernation” and while that’s also an option for some users, there are others that need to leave the computer on 24/7 even if they don’t want the display on constantly. It’s this latter group that this article is aimed toward.
BONUS HINT: If you bought a new monitor on Black Friday and it has a bright pixel, a.k.a. a stuck pixel, you might be able to fix it without returning it to the store. We are not saying this is a good idea, but if you are very careful not to use too much force, it’s sometimes possible to fix the pixel yourself, and if not then you can probably still return it:
How to Fix a Stuck Pixel on an LCD Monitor (WikiHow)
5 Ways To Fix A Stuck Pixel On Your Screen (MakeUseOf)
The only thing we would say different from the advice given is that you should never put any hard object directly against the display, since you might scratch it or worse. In our case, when the software method failed to produce results (always try that first!), we used a rounded pencil eraser and placed a (non-perfumed el cheapo) facial tissue over the screen so the eraser could not touch the screen directly, and tapped lightly in the area of the bright pixel a few times, and it cleared the pixel (we also had a software fix running over the pixel area at the time, specifically this one). The trick is to use a light touch, so that you do not make things worse! If somebody in the next room says “What’s that tapping noise?” then you are doing it much too hard! And you certainly don’t want to mess up the display so badly that the store won’t exchange it.
The most common way to get terminal access to a remote Linux machine is to use Secure Shell (SSH). To work, the Linux server needs to be running a SSH server (OpenSSH) and at the other end you need a SSH client, something like PuTTy in Windows or the ssh command line tool on Linux or other Unix-like operating systems such as FreeBSD.
The attraction of SSH is that the connection between the two machines is encrypted. This means that you can access the server from anywhere in the world safe in the knowledge that the connection is secure. However the real power of SSH is that the secure connection it provides can be used for more than just terminal access. Among its uses is the ability to copy files to and from a remote server.
Full article here:
Transfer Files Securely Using SCP in Linux (Make Tech Easier)
Related:
12 scp command examples to transfer files on Linux (BinaryTides)
From TecMint comes this series of articles…
Linux command line attracts most of the Linux Enthusiastic. A normal Linux user generally posses a vocabulary of roughly 50-60 commands to carry out their day-to-day task. Linux commands and their switches remains the most valuable treasure for a Linux-user, Shell-script programmer and Administrator. There are some Linux Commands which are lesser Known, yet very useful and handy irrespective of the fact whether you are a Novice or an Advanced User.
Now, we personally prefer to do as much as possible in a GUI, but for those of you that prefer the command line, this series is for you:
11 Lesser Known Useful Linux Commands – Part I
10 Lesser Known Linux Commands – Part 2
10 Lesser Known Commands for Linux – Part 3
This looks like a fun but potentially VERY dangerous project – we wish the sites linked below had included some common-sense safety warnings for potential builders. Please be conscious of friends and family members (especially the young ones) that might not fully appreciate the danger. If there are drunk people around, hide this thing, preferably under lock and key!
I recently made a mini CNC laser engraver using two DVD drives salvaged from old computers and <$10 extra parts bought on eBay. The controller of the CNC machine is a Raspberry Pi, a $35 credit card size computer. The engraver turns out to be pretty successful. So I am sharing it with everyone.
Full article here:
A Raspberry Pi controlled mini CNC Laser engraver (fun of DIY)
Additional coverage:
Raspi Mini Laser Engraver (Hack A Day)
Raspberry Pi Laser Engraver Created Using Two Old DVD Drives (video) (Geeky Gadgets)
Home-made CNC laser engraver (Raspberry Pi – this article actually does include a warning!)
Memory Usage
On linux, there are commands for almost everything, because the gui might not be always available. When working on servers only shell access is available and everything has to be done from these commands. So today we shall be checking the commands that can be used to check memory usage on a linux system. Memory include RAM and swap.
It is often important to check memory usage and memory used per process on servers so that resources do not fall short and users are able to access the server. For example a website. If you are running a webserver, then the server must have enough memory to serve the visitors to the site. If not, the site would become very slow or even go down when there is a traffic spike, simply because memory would fall short. Its just like what happens on your desktop PC.
Full article here (tip: if you see a block of run-on text at the top of the page, just skip it and continue on to the next paragraph):
5 commands to check memory usage on Linux (Linux.com)
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