A low-cost general-purpose SCI (Serial Communications Interface) to RS232 adapter that is powered by the PC's RS232 port. It provides full signal (including CTS/RTS) connections for the SCI port of whatever MCU you're using. Its main characteristic is that is it pin-to-pin compatible with the Tibbo EM203 module.
RS232 'self-powered' adapter including hard flow control signals (3V and 5V)
Design and Development of Electronics and Software Systems