Remote Control Transmitter – Rolling Code Key Automation

A remote control transmitter sends a code word to a receiver. If the receiver accepts the code word, it will actuate a relay or open a gate.

Simpler systems use a fixed code; the same code is sent to the receiver every time. This could be discovered by an attacker and used to gain access.


If you are using a simple rolling code transmitter system to open your garage door or to unlock the gate, an attacker might be able to learn the code word that opens the gate. It might also be possible to duplicate the code word by pressing the same button on a different remote control.

A more secure remote control system uses a rolling code, which changes for each use. This means that the codeword sent today may not be accepted tomorrow, but if an attacker knows how to decode the code, he might be able to get the car locked or the gate closed for a while before the receiver learns what he has been doing.

Rolling code systems work by using a pseudo-random number generator (PRNG) to generate a non-repeating sequence of numbers that the transmitter and receiver must check. The PRNG will store a seed value and a number of previous codes used, which the transmitter and receiver can use to perform a calculation on each subsequent code that is transmitted.

The resulting codewords are encrypted with a key shared by the transmitter and the receiver, making it difficult for an attacker to break them. The codewords are then stored in a memory and re-transmitted when they are needed to authenticate or unlock the vehicle or gate.

One method of overcoming rolling code attacks is to send the same code word multiple times, which activates the alarm and immobiliser on the car. It is also possible to jam the transmissions, or to capture and store them for later exploitation.

To add another level of security, cryptographic rolling code systems also include a secret key that is shared between the transmitter and receiver. This key, which is known only to the device that uses it, prevents the transmitter from sending any other codeword that is not valid for the receiver.

In addition, the encryption methods are more difficult for an attacker to break than a fixed-code system. For example, a remote control transmitter that uses the KeeLoq algorithm, which was once the standard on garage and gate remotes, can only be broken by using a specific algorithm and the exact sequence of press-button presses that it uses to transmit its codeword.


Generally speaking, the best remote control is the one that fits in your hand and functions reliably. Luckily, the NICE range includes several top-quality models that can be programmed and tucked away in the glove compartment for the next time you need to leave the house. Moreover, you can rest assured that it will be at the ready when you return – thanks to its robust battery compartment. Taking good care of your remote is the first step to enjoying it for years to come! Besides the obvious maintenance and cleaning, it’s also worth thinking about replacement batteries, which can be as simple or as complex as you wish.


Reliability refers to the ability of a product or system to function reliably under certain conditions for an extended period without failure. It is an essential characteristic that can save money by reducing the number of devices that need to be replaced or repaired.

Reliable research is important because it aims to minimize subjectivity and the impact of observer bias so that researchers can replicate results across the same set of people or subjects. It also aims to minimize measurement error, which is the difference between an item’s score and its true value.

Several methods can be used to evaluate test-retest reliability, which measures the degree of consistency between scores on a test administered at one time and those given later. Using the Pearson product-moment correlation coefficient, this method estimates reliability by looking at how consistently two groups of people scored on a test.

This method can be especially useful when a test is divided into multiple components that measure different aspects of a subject’s personality or behavior. This allows a single test-retest reliability estimate to be computed from the correlation between test scores on all of the components, as opposed to a separate internal consistency reliability coefficient for each component.

A higher test-retest reliability may be expected for constructs that are more stable over a long period of time, such as an individual’s reading ability or his or her anxiety level.

Another method of evaluating test-retest reliability is the Cronbach alpha method, which estimates reliability by comparing the score of a group of participants who took the test to the score of a group of participants who did not take the test. This is a more conservative estimate of reliability than a test/retest, which requires administering the test at least twice in order to calculate a reliability coefficient.

A remote control transmitter rolling code key automation system uses a pseudo-random number generator to generate a rolling code. This is the same system that is used in many radio frequency-based security systems, such as the ones that allow a person to unlock his or her garage door. The resulting code is then sent to a microprocessor that recognizes it and performs the desired action. This type of technology has become increasingly popular in the security industry as it is relatively secure and difficult to replicate.


A remote control transmitter is capable of transmitting a coded signal for actuating a device connected to a remote receiver. The remote control transmitter includes a controller which actuates a transmitter element upon each activation of an activation switch and is capable of selecting one of a first code and a second code for transmitting within the coded signal.

A receiver actuates an electric motor to open or close a movable component upon receipt of a coded signal generated by a wireless remote control transmitter. The receiver demodulates the encrypted RF transmission and recovers the fixed code and rolling code, thereby determining that the signal has emanated from an authorized transmitter.

Various types of remote control systems employ different methods of encoding the transmitted signals to ensure that the received codes are valid. Early systems employed a series of switches contained in both the transmitter and receiver that could be set to any pattern desired by the user.

Today, many newer receivers are “smart” devices which can learn the transmitted code and use that code to open or close a garage door or vehicle door lock. Using this technology, multiple receivers may be used in different buildings. However, it is difficult for a merchant who sells these types of devices to stock separate code key devices for use with each type of receiver.

The present invention overcomes this problem by providing a remote control transmitter that automatically selects one of two different code generating means for use with either older switch-controlled or newer “smart” receivers. This selection method is transparent to the user, thereby eliminating the need for a merchant to maintain a supply of two different portable transmitters or neglect customers who own older, switch-controlled systems and carry only the newer smart receivers.

The receiver of the present invention is able to decode the transmitted signal from the remote control transmitter by executing a non-linear algorithm. When the receiver receives a valid coded signal from the remote control transmitter, it increments a counter and compares the corresponding serial number with a memorised serial number stored in its memory. If the serial numbers match, the receiver generates an output signal to a remote control device to activate the opening of a door or gate.

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