Trinary to trinary rolling code generation method and system

• US 8,077,009 B1
• Filed: 08/10/2009
• Issued: 12/13/2011
• Est. Priority Date: 04/03/2006
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Kraft, Clifford H.
• Primary Examiner(s): Lee, Benjamin C
• Assistant Examiner(s): King, Curtis
• Application Number:
  US12/538,398
• Time in Patent Office: 855 Days
• Field of Search: 340/5.26
• US Class Current: 340/5.26
• CPC Class Codes: G07C 2009/00253 dynamically, e.g. variable code - rolling code
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 2009/00928 for garage doors
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks

Abstract

An all-trinary rolling code method and system which allow a barrier opener to generate and transmit trinary rolling codes without entering or storing any rolling code values as binary words includes obtaining a stored trinary counter value upon a transmitter being actuated to remotely control a barrier. A trinary function void of trinary to binary or binary to trinary conversions is used to transform the trinary counter value to a trinary rolling code output such that the trinary rolling code output represents a trinary value that would be produced if the trinary counter value were converted to binary, mirrored, had its highest ordered bit set to zero after being mirrored, and converted back to trinary. The trinary rolling code output is combined with a stored trinary transmitter identification value to generate a trinary word. The transmitter transmits the trinary word for receipt by a receiver associated with the barrier.

Claims

1. A system comprising:

a transmitter;

a user activation input;

a memory for storing a trinary rolling counter value and a trinary identification value, wherein the trinary identification value identifies the transmitter, wherein the trinary rolling counter value has N digits;

the memory for further storing a table of two columns and N rows, each row of the table representing a value of I from 0 to N−

1, the first column containing trinary values of 2^I and the second column containing trinary values of 2^(N-I-1);

a processor in communication with the user activation input and the memory, wherein the processor;

(a) retrieves the trinary rolling counter value from the memory based on receiving a signal from the user activation input;

(b) transforms the trinary rolling counter value to a trinary code output by performing a sequence of trinary operations void of any trinary to binary conversions or any binary to trinary conversions on the trinary rolling counter value, the sequence of trinary operations including iterating through each table row one at a time for I=N−

1 to 0 and for each iteration, if the trinary rolling counter value is less than the trinary value of the first column of the Ith table row, adding the trinary value of the first column of the Ith table row to the trinary code output and subtracting the trinary value of the second column of the Ith table row from the trinary rolling counter value;

(c) interleaves the trinary code output and the trinary identification value to generate a trinary word; and

(d) transmits the trinary word using the transmitter for receipt by a receiver.

2. The system of claim 1 wherein:

the processor further

(e) adds a fixed value to the trinary rolling counter value to generate a new trinary rolling counter value; and

(f) stores the new trinary rolling counter value in the memory for the new trinary rolling counter value to be retrieved by the processor upon the processor receiving a subsequent signal from the user activation input.

3. The system of claim 1 wherein:

the transmitter comprises an oscillator generating a radio frequency (RF) carrier signal, and a modulator in communication with the processor, wherein the modulator modulates the RF carrier with the trinary word.

4. The system of claim 1 wherein:

the modulator is a pulse width modulator.