When the first Raspberry Pi board was introduced it literally changed the understanding of small computers by bringing Linux closer to us. With great support, low board prices and the huge community it stayed on top next to Arduino for four years. Of course, in to keep that success, updates in hardware and software are mandatory. We know how fast things change computer industry, so time to time Raspberry Pi foundation kept upgrading Pi boards From first, to second and now the newest third generation – Raspberry Pi 3. At first glance, you may see that Raspberry Pi 3 board is practically identical to version 2. component layout is the same including all peripherals. So all enclosures that worked with Pi2 should fit fine for Pi3 boards. But not the most obvious things that make it stand out.
If you are doing some data logging, sensor reading, or another routine task with Raspberry Pi, you probably think of using the database. The list of database software choices is quite long, but you will end with a single or few tables in the database in most cases. The first thought might be MySQL – a well-known database server in WWW. Anyway, this is a pretty heavy tool to have running on Raspberry Pi. In my opinion, SQLite is probably the most suitable choice. Because it is serverless, lightweight, opensource, and supports most SQL code. Another handy thing is that SQLite stores data in a single file which can be stored anywhere.
Recently I’ve received a Raspberry pi camera board. So decided to make a post about it. Raspberry PI comes with two interesting connectors onboard. One is between Ethernet and HDMI, and another is near GPIO. The one closer to the Ethernet connector is CSI (Camera Serial Interface) bus interface. This interface is common in mobile phones with cameras. This interface is specially designed for high data rates that are necessary for transferring pixel data. The camera board is a small (25mm x 20mm x 9mm) board where a fixed-focus 5MP camera module (OV5647) is assembled. The camera connects to Raspberry Pi via a 15cm ribbon cable. Camera module is capable of producing 1080p images at 30fps or 720p at 60 fps and 640x480p at 60/90 fps. Obviously, such images and fps require a high-speed interface and processing. So CSI is connected directly to Raspberry Pi GPU, which can process images without ARM intervention. This is why the camera module is a much better choice than the USB camera, which occupies the main processor and slows down the whole system. GPU processing also benefits with fast H264 video encoding and JPEG compression capabilities.
Probably this would be unwise to go through a long list of available Unix commands. It is quite long, and there is no reason to point out each of them here. You can take a look at some basic ones in the following list. It is more important to learn how to use them and get the desired result by building more complex commands. Commands can also be combined into a single line using piping. In this case, the output of one command becomes the input of the next one and so on. Let’s go with few examples. We all know that Raspberry Pi comes with Python installed. So we should expect to find lots of .py files here: sudo find / -name *.py this throws us large list of file names: Finding and displaying files that way is useless. Viewing is even more painful. Let’s say we simply want to count all .py files. For this, we use the same command, but instead of throwing the list to the terminal, we feed it to another command that does the counting of lines (we get every file in a new line):
It’s been quite some time since my Raspberry Pi Model B arrived. All I’ve done is tried to run several things, blink GPIO with examples found on the Internet, set up a desktop computer for my daughter with TuxPaint. I never was a big fan of Linux; on the desktop computer, I always use Windows for my daily tasks. With cheap single-board computers like Raspberry Pi, people looked at Linux from a different perspective. We can notice an increased interest in Linux, how to do this, and this. Who works with Linux long time? It is just another computer where they can work with it and make cool things right away. But for us like me, it’s a good chance to get to know Linux better and learn a few tricks.