Circuit Lake

Electronic Project and Circuit Collection

ECP Parallel Port Monitor

05/05/2012 Category: Interfacing, Microcontroller, Monitoring, Project, Renesas

This project utilizes the Renesas M16C SKP board to monitor a PC parallel port, set to ECP (Extended Capabilities Port) mode, and dumps acquired data to HyperTerminal via the Com port. The purpose is to allow the user to see the control codes and data that are used by a printer driver and reverse engineer the driver. This information can be used to write ink jet printer drivers for microcontrollers, as an example.

PC Parallel Port Monitor

The hardware for this project consists of the Renesas M16C SKP board, an RS-232 driver circuit and a DB25 plug assembly that taps into the ECP port. The circuit only monitors ECP data and is passive since all ECP connections are programmed as inputs to the M16C processor. The data is transmitted via the serial communication port to a PC running HyperTerminal in 19200 Baud, N-8-1, no handshake. The RS232 driver circuit is located on the solder-less breadboard (see figure).