Along with other Curuxa tools, you have a set of libraries written in C-language available to simplify the development of your programs for microcontrollers.
These libraries are designed to work with the SDCC compiler. They provide functions that execute very common and repetitive tasks, such as setting up digital inputs/outputs or analog-to-digital converters, simple names for variable types, stopping the program for a given amount of time...
For getting a full list of available libraries and functions, run Curuxa IDE and open the libraries. All functions include a short explanation about what they do.
Some libraries and functions require a basic setup before being used. For example, before using delays you have to indicate at which frequency your microcontroller is running at. This is usually done using #define and it's always explained inside each library.
Libraries might be easier to use, but if you want to have more freedom to customize your program and learn how everything works it's recommended to include the library for the PIC directly (#include <pic16fxxx.h>) and use all the snippets you need, instead of using these libraries.
|bool||8||0 or 1|
|int8||8||-128 to 127|
|unsigned int8||8||0 to 255|
|int16||16||-32768 to 32767|
|unsigned int16||16||0 to 65535|
|int32||32||-2147483648 to 2147483647|
|unsigned int32||32||0 to 4294967295|
Boolean variables take 8 bits of RAM but are supposed to store a single 0 or 1. It wastes some memory but this way is much more efficient.
bool MyVar; MyVar = 0; MyVar = 1; MyVar = true; MyVar = false; MyVar = TRUE; MyVar = FALSE;
//set all digital pins as inputs TRISIO=AllDigitalInputs; //set all digital pins as outputs TRISIO=AllDigitalOutputs; //set a single digital pin as input SetDigitalInput(5); //set GP5 (pin number 2) as input //set a single digital pin as output SetDigitalOutput(5); //set GP5 (pin number 2) as output
//configure all bits/pins of a digital I/O port as inputs TRISA=AllDigitalInputs; //set all PORTA bits as inputs //configure all bits/pins of a digital I/O port as outputs TRISC=AllDigitalOutputs; //set all PORTC bits as outputs //configure a single digital I/O as an input TRISB3=DigitalInput; //set RB3 as intput //configure a single digital I/O as an output TRISD1=DigitalOutput; //set RD1 as output
These are individual settings that change the low-level behavior of a microcontroller. They are not stored in RAM but they are not part of your program either. They are special settings you must define so they'll get programmed into the microcontroller while you are writing a program into it.
Each microcontroller supports its own config bits, so you need to check the microcontroller's library and see which ones you can configure.
Features you can usually set:
//models with single configuration word ConfigBits(_CPD_OFF & _CP_OFF & _BOD_OFF & _MCLRE_OFF & _PWRTE_ON & _WDT_OFF & _INTOSCIO); //models with multiple configuration words ConfigBits1(_CP_OFF & _DEBUG_OFF & _CPD_OFF & _LVP_OFF & _BOR_OFF & _MCLRE_OFF & _PWRTE_ON & _WDT_OFF & _INTOSCIO); ConfigBits2(_FCMEN_OFF & _IESO_OFF);
SetBit(MyVariable,3); //bit number 3 of MyVariable
ClearBit(MyVariable, 5); //bit number 5 of MyVariable
RB3=1; //set bit 3 of PORTB to one/true/high bool MyVar=RA4; //read bit 4 of PORTA
//example: we have an electronic circuit which turns on a motor by setting bit 6 of PORTC to one/true/high //...(remember to setup PORTC6 as a digital output)... #define Motor RC6 #define Run 1 #define Stop 0 Motor=Run; [...] Motor=Stop;
Libraries designed specifically for each Main Board. You must include the library of the Main Board you are using.
These libraries provide all previously explained common features, plus some more depending on which internal peripherals each Main Board supports (ADC, timers, USART...).
Typical functions available (open the library to see the full list):
Delays are functions that keep the microcontroller doing nothing, wasting time and energy.
They are usually very inefficient. They are never the best solution for anything, but they are very common because it's the simplest and easiest way to stop the execution for a given amount of time.
Use timers and interrupts if you want to execute something else while waiting.
These functions are very inexact. For better timing use internal timers. For precission timing use Real Time Clocks.
Before using this library you must define the frequency at which the microcontroller is running.
Example of microcontroller running at 8MHz:
#define OSC_8MHz #include <Delays.h>
//...it was doing something... DelaySec(5); //stop execution for 5 seconds //...keep running...
Some available functions:
The entire list of available functions can be found inside the library itself.
Before using this library, the following defines must be set to match the digital pins your L293 is plugged to: M1Enable, M1In1, M1In2, M2Enable, M2In1, M2In2
#define M1Enable RA2 #define M1In1 RA3 #define M1In2 RA4 #define M2Enable RA1 #define M2In1 RA0 #include <L293.h>
Some of the functions available in this library: