External multiple peripheral interface to computer serial port using individually configured parallel port terminals

• US 5,812,879 A
• Filed: 04/19/1993
• Issued: 09/22/1998
• Est. Priority Date: 04/19/1993
• Status: Expired due to Fees

• Current Assignee: Ricardo J. Moro
• Original Assignee: Ricardo J. Moro
• Inventors: Moro, Ricardo J.
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): CHEN, DUO
• Application Number:
  US08/049,174
• Time in Patent Office: 1,982 Days
• Field of Search: 395/250, 395/500, 395/882, 395/891, 395/892, 318/696, 318/685, 371/22.2
• US Class Current: 710/62
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices

Abstract

A multiple peripheral interface to a computer serial port includes a microcontroller with an adapter serial port for coupling to a standard serial port of a common type of host computer or terminal, a plurality of peripheral ports having read/write configurable data lines for coupling to devices of a process, and a central processing unit interfaced between the adapter serial port and the peripheral ports and executing an adapter operating program to translate simple letter commands and numeric values received from the host computer to port configuration commands, port read commands, and port commands and to translate data read from the peripheral ports to numeric values for transmission back to the host computer.

Claims

1. A personal computer parallel interface adapter connectible between an external process and an existing serial port of a personal computer for control of the process by the computer, said adapter comprising:

(a) adapter serial port means including adapter serial port terminals to enable interfacing to an externally accessible serial port connector of a serial port of a personal computer;

(b) parallel port means including a plurality of parallel port terminals which can be individually configured as input terminals or output terminals, said parallel port means being adapted for connection thereto of components of a process external to said personal computer to enable control of said process by said personal computer;

(c) controller means interfaced between said serial port means and said parallel port means, said controller means being programmed to configure said parallel port terminals individually as input terminals or output terminals, to write to said output terminals, to read from said input terminals, and to convey data read from said input terminals to said computer, in response to commands received by said controller means by way of said adapter serial port means and said serial port connector from said computer;

(d) said controller means being programmed to translate ASCII coded commands and control data received by way of said adapter serial port means to machine language commands and control data to configure said parallel port terminals and to write said control data to selected ones of said output terminals;

(e) said controller means being programmed to translate machine language data read from input terminals to ASCII coded process data and to transfer said process data to said personal computer by way of said adapter serial port means; and

(f) said adapter being configured for being positioned and operated external to said computer.

2. An adapter as set forth in claim 1 wherein said parallel port means includes:

(a) a plurality of parallel ports, each parallel port including a plurality of said parallel port terminals which can be individually configured as input terminals or output terminals; and

(b) said controller means being adapted to respectively read from or write to said parallel port terminals of a parallel port simultaneously.

3. An adapter as set forth in claim 1 and including:

(a) pulse width modulator means coupled to said controller means, said pulse width modulator means being controllable by said controller means to output a pulse train of selected frequency and duty cycle in response to commands received from said computer by way of said adapter serial port means.

4. An adapter as set forth in claim 1 and including:

(a) synchronous serial interface means coupled to said controller means and enabling interfacing said computer to a synchronous serial device.

5. An adapter as set forth in claim 1 wherein said computer includes host modem means coupling said serial port to a telephone system, and including:

(a) adapter modem means coupling said serial port means to said telephone system to enable communication of said commands over said telephone system.

6. An adapter as set forth in claim 1 and including:

(a) means for measuring the resistance-capacitance (RC) time constant of an RC circuit including an interconnected resistor and capacitor coupled to one of said parallel port terminals by measuring the time to charge said capacitor through said resistor to determine the relative resistance of said resistor if the capacitance of said capacitor is known and to determine the relative capacitance of said capacitor if the resistance of said resistor is known.

7. An adapter as set forth in claim 1 wherein:

(a) said controller means includes a microcontroller unit.

8. An external parallel interface adapter for external connection to an existing serial port of a personal computer, said computer including host modem means coupling a host serial port thereof to a telephone system, and said adapter comprising:

(a) microcontroller means including adapter serial port means including adapter serial port terminals to enable interfacing to an externally accessible host serial port connector of an existing host serial port of said computer, parallel port means including a plurality of parallel port terminals which can be individually configured as input terminals or output terminals, and central processor unit (CPU) means interfaced between said adapter serial port means and said parallel port means;

(b) said CPU means being programmed to translate ASCII coded commands received from said computer by way of said adapter serial port means to machine language commands within said CPU means to thereby configure said parallel port terminals individually as input terminals or output terminals, to write to said output terminals, to read from said input terminals, and to convey process data read from said input terminals as ASCII coded process data to said computer by way of said adapter serial port means;

(c) said parallel port means including;

(1) a plurality of parallel ports, each parallel port including a plurality of said parallel port terminals which can be individually configured as input terminals or output terminals; and

(2) said microcontroller means being adapted for said CPU means to respectively read from or write to said parallel port terminals of a parallel port simultaneously;

(d) pulse width modulator means coupled to said microcontroller means, said pulse width modulator being controllable by said CPU means to output a pulse train of selected frequency and duty cycle in response to commands received from said computer by way of said adapter serial port means;

(e) synchronous serial interface means coupled to said CPU means and enabling interfacing said computer to a synchronous serial device;

(f) adapter modem means coupling said adapter serial port means to said telephone system to enable communication between said computer and said microcontroller means over said telephone system;

(g) means for measuring a resistance-capacitance (RC) time constant of an RC circuit including an interconnected resistor and capacitor coupled to one of said parallel port terminals by measuring the time to charge said capacitor through said resistor to determine the relative resistance of said resistor if the capacitance of said capacitor is known and to determine the relative capacitance of said capacitor if the resistance of said resistor is known; and

(h) said adapter being configured for being positioned and operated external to said computer.