So lets use this opportunity and move to the battlefield again…

Imagine soldiers running out of the trenches in their next try to keep the deadline take over enemy positions. Rain of bullets falling from the sky, thunder of heavy weapons and sound of explosion all around them.
Wounded people bleeding on the ground, chaos, pain, death and memory leaks…
Now everything stops for a moment. Elegant, new, shiny hummer comes on this battlefield that is covered by the dust, blood and compiler warnings.
Window on the backseat opens and someone from the inside is taking a look on the battlefield and on the soldiers.
Few moments for taking notes.
- Ekhem… – said interior of the hummer – You should use your M16 more effective, throw more nades and don’t bleed so much, ‘cuz you gonna die… Yep, that’ll be all.
Hummer is leaving the battlefield. People bleed the same way, heavy machine guns start their deadly song again.
- WHAT THE HELL ARE YOU WAITING FOR?!! – yell sergeant – You’ve all heard what our highly paid consultant said. Now get back to work, fix the bugs, deliver features or you’ll stay here for next weekend!

However… :-)
Few months ago big discussion was started if this road should be free. Some politicians said that according to European law, new highways must be paid. Because government election is coming our smart politicians have to do something about this. Imagine how happy 600 000 of Wroclaw citizens plus several thousand people from Wroclaw surroundings would be after getting this news. “Well we promised that it will be free… but you know… we promised so many things…”.

Well, our politicians are not _that_ stupid. Big day came, 1st September, ring road to be opened, prime minister of Poland is present in Wroclaw on the celebration with some good news. Looks that the ring road will be free, however it will not be a highway anymore. Because according to law new highways must be paid, so we will just remove the “highway” from the road name. Boo hoo.

They create some silly law they need to bypass later on by removing one word from road description. Then they say that now the speed limit will be lower on this road because it’s not a highway anymore.

Wait, damn it, where this speed limit comes from? Technical reasons – road construction, number of lanes etc.? Or some stupid law created and later bypassed by politicians?

Maybe engineers’ credo “make it simple, stupid” was copied some time ago by politicians…

Unfortunately they have made small mistake and it’s now only “make it stupid”.

In Poland we used to say that people from other countries expects polar bears on our streets.
Of course it’s getting better and better now. Now if you ask German what does he know about Poland he will tell you that it’s a place where they send their wrecked cars. More or less. When Poland was added to European Union Germans on the east changed doors and locks to most solid ones. Companies that installs alarm systems had their happy time.
Friend of mine starts some big deal with one west European company and they are still not sure if they should invest in Poland. “You know, numbers are quite good, but is it really stable and safe in Poland now?”.
Well… No dude… Bears on the street, buckets for shopping, old wrecked cars… By the way could you pay me in vodka and bananas?

When I was a kid I wonder how the hell is this possible that we are poor and in other countries they are so rich.
My friend’s father was in Germany working as a builder. His employer was pointing on him with his finger and explaining to the kids – “you should learn and finish studies or you will end up like this poor polish builder working physically whole days”. Thing is that my friend’s father is a physics doctor and knows three languages. Despite of this fact it was usually only possibility to earn some money to feed the family by this time.

Here we are getting to the point. Why is it so? Why are we now about 20 years behind Western Europe?
Well, it’s very simple. Because we were occupied very long time and most of polish patriots were killed by Germans and Russians during the war.
During the war our both occupiers killed not only polish soldiers, but also most of teaching staff, police officers, other patriots. Basically most of valuable persons. It’s according to 20/80 rule. Most important people were eliminated and it was enough to corrupt whole country for at least two generations.
Some of those people of course survived the war. Most of them were killed later by Russians.
1945 was not end of war for Poland. We were still occupied by Russians. They killed most of survivors from polish army. Good example is Witol Pilecki, author of Aushwitz report, big polish hero, captured and executed after fake trial.
Most of polish heroes were killed and defamed by Russian government. In many cases we don’t even know where those persons were buried. For Poland this was not just a war, all those actions were calculated by Russians to break our nation and they succeeded in big part.

This is why we are now about about 20 years behind Western Europe from political, industry and infrastructure point of view. Luckily we will now have second generation that is not contaminated by war nor occupation.
I just hope that this valuable 20% of polish people will stay in Poland…

In Army there is whole command chain with president or a minister on the top, some generals and captains to work on maps and papers, sergeants and corporal to work with soldiers in the field. And of course the team to kill bad people whatever bad means.
In corporation minister is the CEO/chairman, generals and captains are the upper management to negotiate contracts, create and cancel projects. Sergeants are lower management – team leaders and all other X leaders – they work with the team close to the project. And of course the team to kill… I mean to do the job. Whatever job means.

After years of working with army style management corporations try to be agile. Less management, no X managers, self organising, cross functional teams.
Cross functional teams are quite popular also in army. Team with about seven people with different skills and armament could do a big mess… Isn’t it similar in scrum? No separate testers and developers team in scrum, no separate launcher teams and M16 teams in army :-)).

How might army look like if they use scrum?

Beginning
Sergeant: Team 167, you have to attack the tower…
Team 167: Serg, you have no longer the authority over the team, sir. We will choose our targets after meeting with Captain… I mean Product Owner.

Sprint planning
Captain: Teams, last sprint no team decide to attack the tower. This is the item of high priority and you must do this during this sprint.
Teams: No team volunteered for this item because it’s too big and not clarified enough. Teams would like to know if there are snipers in the tower and how many nades enemy has. Last time we encountered many impediments because items were not specified enough – land mines and one dangerous ambush. Captain, you have to work more on items specification.

Sprint – Daily scrum 1
Sergeant: Team 167, Captain wants us to rescue the hostage. We can do this on our way to the tower.
Team 167: Captain is not allowed to add new items during the sprint. You should know this as a scrum master… By the way, we don’t want you to be our scrum master any longer. You don’t obey to the scrum rules.

Sprint – Daily scrum 2 (sergeant got his last chance :-))
Sergeant: Team 167, I want to remind you KABOOM that you should meet daily. It’s very important to synchronise work between team members and… DADADADA BOOM plan next activities…

Sprint review
Team 167: Captain, we manage to kill enemy and occupy the tower.
Captain: Fine, so item #1352 is finished. Good job soldiers!
Sergeant: Sir… As a scrum master I have to remind you our definition of done. Tower is not jet fortified, tower has no communication with our base and the road to the tower is still mined.
Captain: Ok, so I can’t mark this item as done. Teams please bear in mind that item #1352 has high priority and must be finished until hmmm… release.

Can you imagine? :-)

Of course first part of job interview is always pretty much the same and there are many howtos about handshaking, eye contact and such stuff. Then you have more or less known questions and here is first interesting part.

Beginning is usually simple – where did you work before plus some basic C++ questions. This definitely shouldn’t be the last part. If programming language basis is enough to get the job, and it wasn’t interview for greenhorn, newbie or trainee then you should run away. Really.
“Our system architect knows even how to overload operators in C++”. Dude, run faster!
Even if there was “young but very experienced team” statement in job announcement. Such experience might be painful to share.

Definitely there should be more questions about design patterns, code architecture, uml and tools. If you get this job you’ll probably work with interviewers or people with similar knowledge. If they are better then you – you’ll be able to learn something new.

If everything went well interviewer lets you to ask questions. Think before the interview what could you ask about. All questions about holidays planning, salary, bonuses, social things are important. However don’t forget about technical things.

My favourite is “Do you use stl?”. If the answer is “no” then listen to explanation very carefully. If they work on something with operating system then there is probably no explanation. If you’re told that stl is not efficient, that they developed better and faster library on their own then thank them for their time and flee. Yes, there still are people who reinvent the wheel and poorly rewrite the stl library. We don’t call them morons only because we are well mannered.

More good questions – “Do you use boost?”, “Do you support open source?”, “Do you use any open source libraries in your projects?”. If they don’t want to use free third parties and want to rewrite whole universe their own “better” way then you know what to do.

Of course until you have family to support :-)).

I can’t say bad word on my previous employer – Sonel. Interesting projects and great team, but I just had to try something new.

So now, after one and half year of low-level-but-still-object-oriented programming I’m working on embedded rtos.

By the way – I would like to thank you for your emails – some people asked me for ATMega + CC1000 code. Well I’m very sorry, but it’s not possible to put this project here. First thing is that I should rewrite, test and document part of code and I just don’t have enough time to do this. Second is that I don’t have hardware from this project – it’s property of my University.

It would be really nice to run such project on more powerful microcontroller, but I’m not able do develop boards and port/rewrite code. Just because lack of time.

Clean and well designed HAL hides hardware differences and separates software layer responsible for hardware managing from main application functionality.

There are some issues to consider before designing and coding HAL…

Memory and time…

Simple example below. We need some text debug output working on rs232 in our application.

C_Debug class uses pointer to C_Uart object. C_Uart is an abstract class, part of Hardware Abstraction Layer. Because Send and Receive are pure virtual methods C_Debug class doesn’t know what is the exact uart peripheral. If you implement your own C_Uart<microcontroller_name> class with Send method, you will not have to rewrite software which uses C_Debug.

Of course it’s not so perfect. Virtual methods aren’t so cheap – when you call virtual method there has to be information about exact implementation that should be used. Calling Send method by C_Debug (on pointer pUart) is in fact executing some extra code before executing proper method. Choosing right method is done by checking the virtual table, which should be placed in flash memory.

Of course above uart example is very simple, but imagine bigger HAL with many peripherals – it may cost much memory (vitables) and it may make difficult executing fast functions with exact timing. There are (of course) methods to avoid delays but most of them are more like workarounds then clean solutions.

In Uart example (from this blog) you may see two namespaces – Devs and Periphs. Lets pretend ( :) ) that Devices uses objects from Periphs namespace. The easiest and cheapest way to get portable, HAL alike solution is to cut periphs.h with defines.

#include "uprocdefs.h"
#ifdef UPROC_ATMEGA88
    #include "HAL/ATMega88/uart.h"
#else
    #ifdef UPROC_HC11
        #include "HAL/HC11/uart.h"
    #else
        #error No microcontroller definition!
    #endif
#endif
namespace Periphs
{
    /// UART peripheral.
    extern C_UART UART0;
};

Of course there must be definition of C_UART class in both files and you’ll have to compile proper .cpp file in your project. It could be done in Makefile.
From now on you may use UART0 object from namespace Periphs. There is no virtual methods, C_UART classes from HC11 and ATMega88 directories don’t even need same base class. If C_Debug class uses Send method and this method (same name, parameters and return value type) is implemented in both files this example will work.

Module with max232.

Here in png file.

It’s good idea to make separate, small module for rs232 communication – it may be useful in other projects. You should think about rs232 connector pinout (between board and module). In this case it is possible to plug P2 (RS232) inversely – this may burn up your rs232 module and even com port or supplier.

I haven’t got max232 for 3.3 V power supply so I usually put 5 V regulator on rs232 module. As far as I remember ATMega88 tolerates 5 V on its inputs even when it’s powered with 3.3 V.
To launch this board you’ll need also stk200 programmer, it’s very simple and easy to google.
On this basic board you may run uart example. Of course you need to configure clock speed (fuse bits + uart registers)…

ATMega88 basic board – KiCad project.
AVR ATMega88 – KiCad lib.

Anyway – I had one-week holidays :-) in Poland and Czech Republic. What can I say… They have much better roads. Weather was quite good – nights were sometimes rainy days usually cloudless (in fact I don’t afraid of rain, right..?).

I’m not going to complain or something, but selling alcohol in small towns and villages in my beautiful country should be forbidden. It’s sad that you meet the same drunk morons in front of only shop in the village every day. Fortunately you may still meet some good people and find charming places, usually with no people at all.