Serial programming?

[razor4]

Hello!

I want to work on an application that is transferring some ASCII letters through the serial port of a PC to a microcontroller (So, just Data transferring over the TX Pin of the Cable).

My question is: Does anybody have an easy script, which opens the port, sends a char string or something and closes the connection?

I just need an working script or infos with the essential functions.

Thanks!

[GNU-Fan]

If I am not mistaken, it should be as easy as:

echo "Hello" > /dev/ttyS0
or another device

[razor4]

Yes, it worked perfectly! Didnt think, it would be that easy

Thanks

One last question: How can I receive e.g. the word 'Hello' over the serial interface?

Is there an easy command too?

Thanks in advance.

[GNU-Fan]

/dev/ttyS0 is a device, but can be accessed like any file.
If you echo with to > to it, it is just like writing to a file.

Try it out:
echo "hello" > newfile.txt
and you will have a new file with this content.

The same applies for reading.
A way to display the content of a file is the cat command.
cat newfile.txt

And this is how you read from ("listen at") the serial port as well.

[razor4]

OK, great. That works!
So I write the input to to a file "receive.txt"
Now I want to get the content of that file and save it as a variable in my C Programm. I get the output of the file with

printf("cat receive.txt\n");

But how can I save the content as a variable?


Thanks!

[GNU-Fan]

C has its own set of file routines. fopen, fwrite, fread, etc...