There is a problem with the C program running in keil, please help the prawns

First of all, there is a difference in the definition of void delay1ms(), and the call is as follows:

delay1ms（1);Explain that this function is made of parameters, right, then either the compilation can't pass, if it's C++ support overloading, you can pass the compilation, but you have to find the specific library when you link, and when you can't find it, it will generate your compilation warning c206.

Secondly, this error in C267 is also for similar reasons, you should take a look at the official documentation of C51 for yourself.

The void delay1ms() function must be placed before the function that calls it.

Or, in front, declare it.

The function is not defined before the main() function.

Put this sentence void delay1ms(); in front of the main function. Or write the delay subfunction before the main function.

2 ways Any one will do.

Output 0xf7, i.e. output low at p13.

If you don't press the key in the column where p13 is located, the value read back is still f7.

If the value read back is not f7, then the p13 column has a key pressed.

If it's not f7, what would it be?

That is: 77, b7, d7, e7.

They represent: column p13, several keys of **.

The program then assigns them additional keys.

I've also encountered it before, the system files are missing and can only be reinstalled.

Keil was acquired by Arm in 2005. The two companies were renamed Arm Germany GmbH and Reinhard Keil, CEO of Arm Inc., said: "As a member of the Arm Connected Community, Keil and Arm have maintained a long-standing relationship.

With ARM: With this acquisition, we will be better positioned to deliver a complete solution to the rapidly growing 32-bit microcontroller market, while continuing to support our 8051 and C16x compilers in the Vision environment. ”

Later, ARM Keil launched the MDK-ARM development tool based on the Vision interface for debugging ARM7, ARM9, and Cortex-M cores for the development of the control field.

Your keil is not cracked.,It's still in the restricted version.,You can only compile a program of up to 2k.,You use a keygen.。

I see that you already have a keygen in your file, and the steps to register are as follows:

1 Open Keil, if it is Win7, you want to run it as an administrator, and open the license manage under the file menu

2 In the pop-up box, there is a cid in the upper right corner, copy the code behind the cid.

3 Open the keygen and paste the CID into it.

4 Note that if there are multiple options for the keygen, select the C51, not ARM or anything else.

5 Click Generate and the registrant will generate a sequence number and copy the sequence.

6 Paste the serial number into the new license ID in the keil box and click the button on the right.

7 If the crack code is displayed on it, and it is black, it means that you have successfully cracked it, if it is red, it means that the registration sequence code has become invalid, repeat the above steps 2--7.

In fact, it's very simple, create a project as you usually do and then create a new file, save it directly, it will prompt you to save the name, and the default suffix is. txt, you directly change the name to ***c to save.

Then right-click on the directory on the left where you put the source file, and an add... will appear in the menuOptions such as files,After selecting, a browse dialog box will appear,Find the ***c file you just saved and confirm to add it.。

You can write your C program in it.

Note that it looks like there will be no response after you click on the add, but in fact, the C file has already been added to the project. You come out and take a look and you'll see that he's already there.

When compiling with Keil programming software, "target not created" always appears due to the creation of engineering errors, and the specific compilation steps are as follows:

1. Select [Project] - [New Project] from the drop-down menu at the top of the software.

2. In the pop-up window, select the project file. (If there is no project file, create a new project file and fill in a noun point to save.) Dust file.

3. Choose a single-chip microcomputer model (such as 89C52, or 89C51).

4. Right-click on the left project "Source Group 1" and select Add a C file to the project group. (For example, add the following C program file.) ）

5. After adding, you will see the name of the C file on the left side, and double-click the file to program on the right side.

6. After completing the C program, compile it into a HEX file, which is used to write it into the CPU microcomputer.