The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 2004
Filed:
Apr. 25, 2000
Terence E. Crimmins, Northport, NY (US);
Eric J. Robb, Carol Stream, IL (US);
The Chamberlain Group, Inc., Elmhurst, IL (US);
Abstract
An RF transmitter capable of transmitting a plurality of different codes at a plurality of different frequencies is set forth herein. The transmitter offers a new way of multiplexing inputs so that fewer controller I/O ports are needed to read or determine the state of a plurality of inputs. More particularly, the controller is capable of using one pin as both an input port and output port and determines the state of various inputs by detecting changes to the I/O pin. The multiple inputs connected to the controller pin are also connected to a pull down resistor and capacitor, and the controller can determine what state the inputs are in by detecting whether the pin input is at a logic high, low, or some state in between.