First, it would be worth considering whether such a division even exists at all.<\/p>\n\n\n\n
In my opinion, this division isn\u2019t entirely appropriate. C is C.<\/strong> Period. It contains several dozen keywords describing various statements, data types, specifiers, etc. We use exactly the same ones when writing programs for a PC and the same ones when writing programs for microcontrollers.<\/strong><\/p>\n\n\n\n The differences we should be talking about are at the level of how we use the language.<\/strong> We\u2019ll write programs a bit differently for an MCU, and a bit differently for a PC. We have the same statements available, but we\u2019ll use some more often and others less often. That\u2019s what this is about.<\/p>\n\n\n\n Bitwise operations are the norm<\/strong> when you write code for a microcontroller. Seriously.<\/p>\n\n\n\n At university, when learning C programming, we studied on PCs. I don\u2019t remember needing bitwise operations while writing various sorting algorithms, tree searches, Dijkstra, etc. Everything was done on \u201cwhole\u201d bytes.<\/p>\n\n\n\n It\u2019s different on a microcontroller. When accessing registers<\/strong>, if you want to set a parameter, then bit-level access is mandatory.<\/strong> Why? Because within one register, each bit can correspond to a different thing. In integrated circuits, silicon is saved, so everything is tightly packed.<\/p>\n\n\n\n So if you want to change something in such tightly packed data, you have to perform several bitwise operations.<\/strong> For example, mask<\/strong> other values you\u2019re not interested in so you don\u2019t accidentally touch them.<\/p>\n\n\n\n In a microcontroller, pointers are everywhere. If you ever program directly on registers, then writing to a register is precisely writing to a specific address in the microcontroller\u2019s memory.<\/p>\n\n\n\n Naturally, you have to treat such a register write as a write through a pointer, or more precisely, writing a value to the place the pointer points to.<\/p>\n\n\n\n Going further: there is a statement that if you want to write efficient C code, you must avoid copying data from place to place.<\/strong> This is exactly what pointers help with. You pass the address of the place<\/strong> where the data you care about is located and\u2026 you work on the original<\/strong> without the need to copy.<\/p>\n\n\n\n Not everyone realizes this, but the C standard library for PCs differs from the one for microcontrollers.<\/strong> Not at the level of whether a function exists or not. Although I once was surprised that I was missing the itoa()<\/em> function in avr-gcc\u2026<\/p>\n\n\n\n The point is that the implementation of standard libraries is different.<\/strong> After all, you have to use different CPU instructions to achieve the same effect. Some topics need to be approached differently.<\/p>\n\n\n\n Unfortunately, implementations for microcontrollers are not great. By including such a printf<\/em>, you also include a bunch of other libraries. That starts to weigh a lot. The code simply bloats and takes up a lot of space in the microcontroller\u2019s memory.<\/p>\n\n\n\n Another example is dynamic memory allocation<\/strong> using, for example, the malloc function. The standard, and especially the implementation, is not clearly defined. We cannot rely on it because it is unpredictable.<\/strong> On a microcontroller, we can\u2019t afford such a large uncertainty. Especially if we are building systems related to human safety.<\/p>\n\n\n\n I created a course dedicated to microcontrollers. In it, I teach C from the ground up<\/strong> (the course content is conducted in Polish).<\/p>\n\n\n <\/p>\n\n\n\n I gathered my experience from several years of embedded programming<\/strong> and I want to pass on the best possible knowledge to you. I participated in various projects: on my own, a start-up, a medium-sized company, and a huge corporation.<\/p>\n\n\n\n In addition to the basics and syntax, I share a ton of good practices.<\/strong> I weave this in between explaining subsequent aspects of the C language.<\/p>\n\n\n\n An additional advantage is also that I show how to run a project well.<\/strong> I\u2019ll show you how to deal with building abstraction layers. We\u2019ll use structures, pointers, and callbacks<\/strong> for that. And of course, splitting into files. That helps a lot.<\/p>\n\n\n\n Such separated layers are much easier to \u043f\u0435\u0440\u0435\u043d\u043e\u0441 between projects, and even between different microcontroller families.<\/p>\n\n\n\n How to join the course? See the full offer at https:\/\/cdlamikrokontrolerow.pl<\/a><\/strong> (the course content is conducted in Polish).<\/p>\n\n\n\n Don\u2019t wait, because the offer is valid until Friday, October 29, 2021, until 20:00.<\/p>\n\n\n\n I hope we\u2019ll see each other in the course!<\/strong><\/p>\n\n\n\n P.S. Let me know in the comments whether this lighter topic on the blog is interesting!<\/p>\n\n\nSo where is the difference?<\/strong><\/h2>\n\n\n\n
Bitwise operations are everyday life<\/strong><\/h2>\n\n\n\n
Pointers, pointers everywhere<\/strong><\/h2>\n\n\n\n
Standard library<\/strong><\/h2>\n\n\n\n
Where to learn C for microcontrollers?<\/h2>\n\n\n\n
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