Solve the problem of error l6218e undefined symbol XXX

Share a keil Error compilation prompt and its problem solving method , When we meet "Error L6218E Undefined symbol XXX…" This error message , In fact, the reason for this problem is that we call undefined functions , For example, you annotate a function definition , And then the program called it , When compiling, you will be prompted to appear the symbol of bit definition .

So the solution is to check whether the function or variable that prompts the error is undefined or declared .

Of course, some people say , This error message will also appear if the parameters of the called function are inconsistent with the parameters of the function itself , But personally, I think this should prompt that the number of call parameters is inconsistent . But you can also go and have a look , See if inconsistent parameters will pop up L6218E This kind of error hint .

My level is limited , The above information is for reference only , If there are mistakes and irregularities , Your advice are most welcome .
Besides, it's not easy to create , Don't copy , If it helps you, I hope you can like it , thank you ~