final.ino: In function 'void setup()':
final:30: error: invalid conversion from 'char' to 'char*'
final:30: error: initializing argument 1 of 'void send_msg(char*, char*)'
I'm not sure what you intend to do there neither of those variables has anything in them at that point.
But either way, number is declared as a char. The function expects a pointer to a char. An & in front of number will clear the error but probably won't work like you expect since the function is using it as a string. It would need a trailing NULL to work there.
but probably won't work like you expect since the function is using it as a string.
No, it won't. number needs to be a string (an array).
And, as Delta_G alluded to, both number and msg need to have values assigned. Sending an empty message to an undefined number is a waste of effort (and you will be charged).
here is the original code that i want to modify
i want to change the number to a variable depending to the receive data from the pc as well as the message("hello") this code it is working ,what i need to do?
The Knights happen to have a weakness in that a number of words, when spoken to them, has the same effect on them as their saying "Ni" has on others. The only one of these words that is revealed in the film is the word "it", which is picked up on when Arthur, upon being asked to cut down the mightiest tree in the forest with a herring, declares that "it can't be done." Ultimately, King Arthur and Sir Robin (who shows up with his own knights) both say "it" several times in conversation (unaware that "it" was the word that was causing the Knights' pain). However earlier in the very same scene the head Knight himself uses the word ("It is a good shrubbery.") suggesting that it only causes the knights pain when said by someone else.