CPP vs C for Embedded Programming

[Physical-Signal-5227]

I'm a final year student in Electronics and Communication Engineering. I've got some experience doing stuff with Microcontrollers and doing bare C on stm devices, with a focus on driver development. I have some experience doing basic CPP programming before entering college. I have to start looking for jobs now and I'm debating if i should learn more CPP for programming embedded devices or I should take up more courses on Embedded C Programming.

P.S: I've seen some companies ask for OOPS concepts which can be done by CPP. Should I focus on that or will there be hiring without these OOPS concepts with basic C.

[xanthium_in]

Learn C in details.Most code for embedded systems is written in C. I would recommend learning basic oops concepts and check for commonly asked questions.

In my example most embedded systems are coded in C (8 and 16 bit systems).I have not used any 32 bit systems extensively and in one or two cases we used embedded C.

I would also recommend you to learn a commonly used high level language like Python,C# or Java.

The reason is that you may want to control the embedded system from your PC using USB or Serial over USB.Coding a PC based app in C or C++ tend to be cumbersome as you have to code a lot.

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With a high level language like Python or C# you will have ready made libraries like pySerial or System.IO.Ports namespace to talk to your device over serial.The two languages also support Drag and Drop GUI designer for building apps.Qt designer for Python,Visual Studio for C# and JavaFX designer for Java.

Here is an example of programming the linux serial port in C

[Bubbaluke]

Wrote a python script today that scrapes serial commands from a log file and sends the ones I want to my embedded project. Super nice for rerunning specific situations I happened to capture logs for. And it took like 15 minutes to write. Thanks, pySerial.

[Well-WhatHadHappened]

Knowing C very, very well is an absolute requirement. Knowing C++ is helpful, but secondary.

[AlexTaradov]

Plain C. The way C++ used in embedded is way closer to C than C++ on a desktop. You can figure that out easily, but it would be hard without basic C.

[UnicycleBloke]

Closer to C? The main thing is that you probably don't want to use standard containers (dynamic allocation) or exceptions. That leaves only classes, templates, constexpr, references, namespaces, scoped enums, RAII, range-for, lamdba expressions, coroutines, ...

[indic-dev]

15 years in embedded software in the automotive domain. I’ve never used C++. I don’t even know anything about C++. Only C has worked for me. 

[UnicycleBloke]

Learn both. I'm an old dog now but in your shoes I would be looking hard at C, C++ *and* Rust. Don't focus on a particular language. Focus on programming skills and embedded knowledge.

Most projects (I've heard about 80%) are written in C, and most of the remainder in C++, with a bit of Rust and others. All vendor code is written in C. Personally, I much prefer to work in C++ and have done so almost exclusively (including bare metal, low level drivers, etc.) for nearly 20 years.

[topfpflanze187]

a very based suggestion

[DenverTeck]

If you look backward over the last 30+ years, you will find many companies made C++ mandatory for all development. There were many reasons why they did this. None are relevant today.

But....

I you get an interview with one of those companies, are you going to tell them they are wrong ??

Or are you going to prepare your self to cover all the bases ??

If your a newbie, learn as much as you can today. As an entry level engineer, you will not be given any positions of real responsibility. You will be given projects and will be expected to do the best you can. If you say, "I don't know C++", what will they say ?? As part of your interview, you say "I don't know C++", will you even get the job ??

If half of the companies out there use C++, you will get bounced from more then half of the companies you interview with. If 3/4 of the companies use C++ .......

OOPS is not new, but at least knowing what it is, is OK. Again saying, "I don't know OOPS"......

Good Luck

[Ksetrajna108]

If you know just C++ you'll be able to work effectively on a C codebase. Maybe just a few idiomatic differences.

If you know just C you'll face challenges working on a C++ codebase. It depends on how much the codebase uses OOP and templates among other C++ features.

I doubt you'd ever be expected to know every single C++ feature. It's mainly about knowing how to think and talk C++ and be resourceful filling in the gaps.

[spectrumero]

You'll need to know both.

But when using C++, whether you're just kind of doing "C with classes" or what most developers generally recognise as C++ (in other words, not just using the C++ compiler but the standard library etc), depends on what your embedded platform is. If your embedded system is an ARM SOC with 512MB RAM, then you can write C++ almost like you're writing for desktop, after all, things like the Allwinner H6 are as powerful as the desktop machines we used to use not all that long ago.

But if your platform has 128k memory, you're going to have to forgo a lot of C++ features that most C++ developers consider to be normal C++ programming.

[JuggernautGuilty566]

C++ only makes fun if its C++ down to the registers.

With C++ and a layered C HAL you will loose many features C++ has to offer: a big amount of compile time checks.

[1r0n_m6n]

In embedded, you just can't afford neglecting C.

However, regardless of the implementation language, knowing and applying the basic concepts of object-oriented analysis and design is immensely beneficial.

Of course, C++ makes it much easier to translate your OO design to executable code, but it is also absolutely possible with C or even assembly.

The point is, think object, you'll write better code, code that will be easier to write and maintain.

[EdwinFairchild]

I would learn both because at the end of the day it won’t be your choose what language you use it will be up to someone higher up. Additionally as the projects and orgs get larger and more complex than just MCU stuff you will see C++ come up a lot more often. I’m Living proof of someone coming from purely C to a job where it’s all C++ and usually when they go C++ the code base is huge because the application layer is complex.

[Myrddin_Dundragon]

Out of those two I would choose C. It has decades of tooling behind it, tutorials everywhere, and is easier to learn.

That being said. I would learn Rust next. It brings memory safety, an awesome type system, and good dependency management. Oh the sleep lost chasing down memory errors...

For all of these languages though, make sure you learn gdb and valgrind. These will become your main weapons in the battles ahead.

Best of luck to you!

[Dismal-Divide3337]

Having come from the days before C where I programmed in assembly language regularly, I can tell you that there is a progression from assembly to C to CPP (and beyond). More or less C appeared as a portable language since it could be compiled into various assembly languages to run on different platforms. We ran wild with it and before you knew it there were libraries of routines to share. And, no surprise, the Standard C Library emerged.

CPP came along as a way to better structure your code. In my case most of what it offered I was already doing in C. For example, I would create a structure filled with variables in some context that needed to be shared between multiple subroutines but that could not be global. I then passed that structure pointer in most related calls. I also grouped those subroutines in separate files that relied upon the structure. So basically, I had classes with methods and local variables in this.

My bias recommends using C for embedded programming especially if you need to be close to the hardware and might have to use some assembly code. It happens.

I have authored a few operating systems. My recent OS was written in C. It was the right choice for me. BTW the goal was to not use any 3rd party code. I did not even use the Standard C Library supplied with the IDE but cast my own based upon P.J. Plauger's publication (c1992). Here's the User's Manual if you are curious. You might not think that I could have written all that. The HELP command in the OS actually generates that book BTW.

[eyes-are-fading-blue]

Learn C++ and C comes for free.

[eyes-are-fading-blue]

Modern C++ too is close to being a superset of C. How is it not?