Objective: To create a RS232 to TTL converter circuit
Analysis/Procedure:
RS232 is an asynchronous communication protocol that lets you
transmit and receive data between DTE (Data terminal Equipment) and DCE (Data
Circuit Terminating Equipment) such as modem.
It is the EIA/TIA (Electronic
Industries Alliance/ Telecommunications Industry Association)
that defines physical
and electrical characteristics of
the RS -232 interface.
RS-232
is active low voltage driven interface and operates at between -12V and +12V for which signal
is LOW or
0 when voltage
is higher than
+3 Volt and
signal is HIGH
or 1 when voltage is lower than
-3 Volt. For any voltage falling between +3 Volt and -3 Volts are considered
„dead area‟ or indeterminate value. TIA defines the power level for short
circuit protection to be
100mA, however most
RS-232 drivers will
provide lower short
circuit protection.
