Linux on board. How to make an Arduino likeness from scratch?

Question

linux

Comrades, I wanted to start moving towards the creation of microcomputers
. Tell me, please, where can I read something "for dummies" about boards, how to poison them, how to solder, how does it all work?
It is interesting to make a certain board with a wi-fi adapter, an ethernet adapter, a usb adapter, and maybe something else.
I would like that when this board is connected to a power source, you can get into Linux via ssh, which is spinning on it (flash memory? Some kind of analogue of ssd with your own hands?) and be happy :)
I don’t want to buy Arduino and others like them - too expensive for experiments
And in general, I want to do everything myself
I don’t understand how it all should work, because a classic computer is at least a processor, RAM, a hard drive, and, well, a board that controls the whole thing
. But on a small scarf, how to bring it all together is a mystery
Thank you all in advance!

Answer 1

First, you will have to choose between your own board and Linux.
The fact is that in order for Linux to work without crutches, you need a controller with MMU support . In fact, this means that you need Arm Corttex A . But these are quite complex controllers, involving complex harnessing, and - most importantly - a large number of legs. Even if you manage to catch the disappearing view of Cortex A not in a BGA package, which is simply impossible to solder without experience and special equipment at home, then you will have very big problems with manufacturing the board and soldering it without a soldering station, which costs not so much little money (if BGA needs at least somethingsuch , then it is very inconvenient to solder ordinary frameless elements without a station)
In fact, developers of equipment of this class almost always use developer boards, of which there are a huge number for all sorts of different applications and completely different costs. The Raspberry Pi also belongs to this class of boards, but definitely not the Arduino.
On the other hand, you can take a ready-made debug board and connect additional modules to it using the same breadboard for switching - perhaps this is exactly what you want)
If it is more important for you to assemble something yourself, then you need to focus on Atmel AVR (or PIC?) controllers in DIP packages. It is still more convenient to prototype such controllers on prototyping boards ( with holes ! By the way, it is convenient and budgetary), and ready-made solutions can already be tried using the LUT method and a Soviet soldering iron for cryptanalysis.
In general, of course - electronics is a rather complicated matter, if you do everything by hand. That's why Arduino and Raspberry PI were developed, with a set of compatible components that can be plugged into each other. You should start with them - your choice is Raspbery PI with Linux, STM Discovery as an advanced ARM without OS, and Arduino.
If you like it, study the architecture of processors from the point of view of a programmer and circuitry from the point of view of developing electronic stuffing

Answer 2

Buy a raspberry to get started. Then, if there are not enough opportunities, take some kind of cubetruck.
And doing it yourself (and, judging by the text, with absolute zero knowledge) will be much more expensive. At least just buy such a processor: after all, no one will sell them individually, at least a package of several thousand pieces! Or from intermediaries at a horse price.
To understand electronics, you need not only to study Tietze-Schenk, Horowitz-Hill, etc., but also to know physics well, be able to program (if you need digital electronics), etc., etc.
PS As an example, the development of a prototype usually has a very high cost. For example, we have already spent about a hundred thousand rubles for the control system of one device! Given that what happens in the end, some Chinese could well spank thousands of 2-3!

Answer 3

For the listed requirements (wi-fi, ethernet, usb), it is best to buy a ready-made solution, this is a router, for example mr3020, it costs 700 rubles and there is built-in Linux and all the necessary interfaces. You can also unsolder uart and i2c there if you really want to solder.
And if the main goal is to do something yourself, it is better to start with a multivibrator, not a computer.