Let's say this is an offside post. It doesn't concern any serial articles about FreeRTOS that I've started.

This article is also available on my Hashnode account.

So we need to write the firmware for our next embedded project

As (young 😃) IoT developer, I spend more times to write code which run on MCU (ATmega/Arduino) and get data from sensors and control or interact with other devices. And it is something that I like. You read sensors or electronic component documentation, you come back to write the code to control it and add other pieces of codes to execute some new actions. So I will share here some advices or steps that I follow to write firmware on embedded projects.

firmware: source code which runs directly on device or on microcontroler not on software or an OS.

To get started

1. You need to express concretly your goal when start this project, you can ask yoursel: What do I want to archieve at the end? It is very important to have a clear vision of what you want to do like control the house's lights, connect your device through the Wi-Fi module (I'll write a next article on Wi-Fi with ESP8266 😎). Then you can now:

2. Divide your goal into small tasks and it is the main part to write code (new source code) for your project. Your goal is like a house where there are some rooms with toilets, the garden,...So you need them to know how to start but also what is important to do firstly, what can be used accross differents pieces of your code and which components, kind of sensors you need.

Let's say you have this:

Now you know the main parts, you can jump to the code, finally we going to the space

Here I usually proceed like the OODA loop model:

• I Observe my tools (sensors, devices) by testing some codes to understand their operation then,
• I can Orient my reflection based on my needs and the components' features so,
• I Decide to how I can write/start my code and
• I Act by writing the code and test it and if needed, I come back to the first step Observe and start again the loop.

It is very important to have such kind of process that you follow and evolve to archieve your goal. It'is not sound like the Holy Grail, I try just to get some habits which will help me in daily tasks.

But actually what is contained in each Steps

1. Test each components of your system

You need to be sure that each component of your project work. To do that, open a plain file code where you test each of them if it is sensors or other things that a code can run. So you can approximatively say that you're working in stable environment. - [Observe]

2. Put together each pieces of code

Based on you projects needs, you can write separetly each piece of code but in the way (order) to archieve the goals. Each time you're sure about the running of a code you can add it to the main code and test it. - [Orient/Decide]

3. Test new code or little code

Take in your mind: YOU NEED TO TEST/RUN EACH PIECE OF CODE YOU ADD. Don't wait to write a lot of codes before test it or before get insurance about its working. If not you will have at the end of your day or project a bunch of codes with many bugs may be independants or not to fix. And you can trust me IT IS THE MOST BAD SITUATION THAT YOU CAN ENCOUNTER. Why? Simple: You'll start to search the begin of the each bugs (which is not easy in this case), you will try to fix it and the result is the rise of another bug or its creation. So test each new code and detect quickly an error. But in many cases some bugs occurs when adding another code but in these cases you're oriented or you need to go back the first steps above. -[Act]

And?

I'll give you somes tips here that I use sometimes

• To test a code that need an electronic component which is not sensor, I write it as a function with parameters. And in a loop I pass it arbitrary or random data

• Read carefully about each sensors (google search, blog articles) or official documentations to have an overview of the sensor's running

• Don't forget that you write code for MCUs so space, time consuming are delicates

• Write one function per action and each component has its section of code write in functions

• Try to have functions with return type and that take parameters to avoid many sub-calls of void function in functions body

• If you're write code in C++, prefer using references over pointers to avoir leaks memory problems

• If you have collections of data, or some relatives data to share between functions or some parts of your code, think to use C/C++ structures (struct) to take them together

• Write simple code because simple code is more easily to maintain and understandable

• If you don't correctly know the behavior of some features, don't use it in enterprise code or short time projects

• Keep in mind you goal and

• Have fun when you're coding, not be afraid to make mistake: EACH ERROR CAN HELP YOU TO REALIZE YOUR DREAM.

Voila, you get it

If you already have some basics in programming these advises will sounds familar to you. Software engineering is like any careers paths where you need to practice to make perfects so do it but smartly. I share some tips that I used in my daily tasks and I hope you've some others tips that you want to share with us. I'm open to new tips and advises, my social accounts (below) are there for this purposes...

So can you smell what TawalMc is cooking?