A preliminary understanding of 51 single-chip microcomputer-2.4 single-chip C language modular programming

Here is a section to talk about modular programming of C language for microcontrollers. What is modular programming? All the codes we wrote before are in the led.c file. Imagine how to read if there are too many codes. In addition, how can people who work with you understand your code? Simply put, there is no readability and portability. Modular programming is to solve this problem. When a project is large, we will divide the project into sections of tasks, and each person completes different sections of tasks. At the same time, each section is connected. Suppose developer A needs to use a certain functional module of B, then A only needs to pay attention to the function of the module and how to call it, and as for how this function is implemented, it can be ignored. In addition, for a single person who has developed a project, the next project may need the same functional module. Similarly, you only need to know how to call the module, and there is no need to study the process of implementing the function of the code. Another project is too large and errors occur, which is not easy to troubleshoot. However, if you troubleshoot according to the idea of ​​​​one module at a time, the idea will appear clearer.

Next, let's take a look at how to establish C language modular programming for microcontrollers

(1) Open Keil software, Project->New uVersion Project

Open the led folder, enter led in the file name and save it.

(2) Select the MCU model. I have already explained it before.

(3) A dialog box pops up, select yes

(4) Create a new blank file or press ctrl+N, then save (ctrl+S) and name it src

Then double-click the src folder, enter main.c in the file name and save it.

Enter the following program in main.c:

• #include

• void main(void)
• {

• }
• Then save

(5)点击project->options for Target ‘target 1’…   

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(6) In target, select crystal oscillator as 11.0592

(7) Then click output, check Create HEX File, and then click Select Folder for Objects…

(8) A dialog box will pop up. Create a new folder and name it output. Double-click the output folder and click OK.

(9) Then click Listing, then click Select Folder for listings

(10) Double-click output in the pop-up dialog box, click OK, and click OK again.

(11) Return to the main interface, right-click the source group, and select add files to group "sourcegroup1"...

(12) In the pop-up dialog box, double-click src, click main.c, click Add, and then click close.

(13) The source code is stored in the src folder. When we click compile, the output-related files will be stored in the output folder.

(14) Now we create four new files, led.c, led.h, delay.c, and delay.h. We divide the previously written program into three modules, main.c, led.c, and delay.c. To create these files, click Create Blank File (ctrl+N), then Save (ctrl+S), and select the save path in the src folder. If you want to create led.c, the file name is led.c, and if you want to create led.h, the file name is led.h

(15) After building these four files, enter the following content in led.c:

• #include

• sbit LED = P1^0;
• void ledON(void)
• {
•         LED =0;
• }
• void ledOFF(void)
• {
•         LED=1;
• }

Copy code

Then click Save.

Type in led.h

• #ifndef _LED_H_

• #define _LED_H_
• extern void ledON(void);
• extern void ledOFF(void);
• #endif

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In delay.c, enter,

• unsigned int i;

• void delay(void)
• {
•         for(i=0;i<30000;i++);
• }

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In delay.h, enter:

• #ifndef _DELAY_H_

• #define _DELAY_H_
• extern void delay(void);
• #endif

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In main.c, enter:

• #include

• #include "delay.h"
• #include "led.h"
• void main(void)
• {
•           while(1)
•           {
•                   ledON();
•                 delay();
•                 ledOFF();
•                 delay();
•           }
• }

Copy code

(16) Add led.c, delay.c files

(17) Click Compile, check for errors, and complete.