Interface Conversion Between RS232 and PS/2

Figure 1 

The project illustrates the use of bit-banging on a 12F683 device by the PS/2 interface which can come from the mouse or keyboard with the other side of PCB having RS232 serial interface while being combined by microchip PIC microcontroller.

The mouse or keyboard is initialized by the PS/2 interface as it functions as a host before going into a never ending loop of reading the data. The data will then be sent to the RS232 interface which refers to waveforms that operate at 5V TTL levels and could destroy the PIC device if it operates at 12V levels but between them, an appropriate converter must be used. The only IC mounted approximately in the center of the PCB is the PIC microcontroller and the two interfaces on both sides.

Other components installed in the device include two pull-up resistors in the PS/2 interface, a decoupling capacitor in the IC, and an ICSP socket with 1 resistor and 1 diode. The whole circuit can be placed in a small box by sticking the PCB into the base of the enclosure to provide convenience since the circuit has been built on a stripboard.

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