i have read that the computer and micro sends ascii codeYou do not yet understand the task fully enough.
ASCII is a way of interpreting
Set up your AVR to transmit serial communications at your chosen baud rate and "N,8,1" communication parameters (N
o parity, 8
data bits, 1
Remember that the transmit pin of one device must be connected to the receive pin of the other and vice versa. They are different pins on 9-pin connectors vs. 25-pin connectors. Watch out.
On the PC side you need to configure the serial port to match the baud speed and communication parameters of the AVR. You may also need to tell your compiler or application to treat the data as binary and to declare no "flow control."
RS-232 serial communication is simple in theory. In practice there are a number of snags and pitfalls like baud, parameters, wiring, hardware/software flow control, error control, etc.
You should study Jan Axelson's serial communications book. Its widely available on the ebookz community and here on sonsivri.