That’s something I wanted to do for quite a long time now : Creating some programs for PIC chips. I bougth the ICD3 programmer/debugger with the PICDEM Z development kit (for ZigBee communication). I can’t say it was chip (it costed me 500 €), but I’ve made a good use of it.

The thing is, it brings me back to my first C programs. It’s quite hard to come back to some unmanaged, memory limited, namespace less language. I thought the lack of objects would be the hardest part, but in fact it’s not (you can easily emulate it). The hardest part is the lack of namespace and the massive use of #define, I really would be happier with a some sort of limited version of C++. The MPLAB development environment is awful (compared to Visual Studio): no reindenting, no refactoring, no smart-anything. This is WILD for me. It’s like being a citizen in the jungle.

I took back the old Doxygen to add some pretty doc.

I’m doing it step by step, 2 to 3 hours some evenings. I started by being able to use the leds, then the buttons, then the serial port (using the UARTIntC library). Recently I added MiWi protocol support. My two chips are connecting to each other and sending messages to each other just fine.

As you can guess, programming this kind of equipment is much less fun than doing some C# .Net. But it has the major advantage of running on very low-cost (less than 4€) chips.

There are some funny things with the Microchip PIC18 Compiler (MCC18).

If you take this code :

File buttons.c:

#include "buttons.h"
// Some stuff
}


File buttons.h:

void buttons_Task();


It produces this error :

Warning [2058] call of function without prototype


The reason is that you must declare your prototypes with no arguments with a void. You have to declare it as void buttons_Task(void);. Well, thank you Microchip for the dumb pre-compiler error messages.

I also discovered that they are two memory (data and program memory).

In one file I had an extern unsigned char *var; and in the other one : unsigned char var[8];. The thing is the compiler doesn’t throw you any warning but when you will copy data from this variable, you will get some other data. Because the C programs doesn’t use the same memory in the two cases. MCC18 doesn’t detect this and the debugger doesn’t help much because it chooses one variable.