MCU Serial Communication - Character Array

As can be seen in the previous article, using characters one by one to judge commands and communication protocols is not only troublesome, but also has great defects. For example, if a string is entered, it will be executed as long as there is a command, and the program in the previous article cannot handle some special strings (the stop command is end, but if an en is entered, it will be stuck in the while (RI==0) statement. There is no input of the next character. RI is set to 0 in the above program, and it will not come out of the while statement. If it is set to 1 at the beginning, the next character cannot be received)

So I started to think about using character arrays to process commands again. Before using the last program, I actually used character arrays to do this program, but there were always some problems that were not solved; yesterday I used C++ to make a character receiving and reading function, and then used Keil to make the same program and found that I still used some of the same:

There are two forms of defining character arrays in C language and C++:

For example, (1) char t[6]="start"; the length of this string is 5, but the system adds a \0 at the end of the string by default; so a character array with a length of 6 bits is required to store it. If 5 bits are defined (t[5]), the compiler will report an error saying that the array cannot be stored;

(2) char a[5]={'s','t','a','r','t'} This definition can omit the system default \0, but it can be clearly seen that this definition method is not practical for defining long strings;

Define the array in keil:

The second method above can also be defined, but the first method will be used differently:

Define a start array: char t[5]="start"; Obviously, the compiler in Keil does not give a default \0 to the character array. This is the difference between the two compilers.

In some cases, this difference can be fatal:

#include
#include
#include
#define uchar unsigned char
uchar t[5]="start";
int i;uchar a[5];
void main()
{
TMOD=0x20;
TH1=0xfd;TL1=0xfd;
SM1=1;SM0=0;
REN=1;ET1=1;TR1=1;ES=1;
while(1)
{
for(i=0;i<5;) //Input into the array
{RI=0;
while(RI==0); //If the length of the string defined here is 6 bits, it will keep waiting for the sixth input, causing the program to fail to execute
a[i]=SBUF;i++;
}
for(i=0;i<5;) //Output to the computer through the microcontroller
{
SBUF=a[i];
while(TI==0);i++;TI=0;
}
}
}