KR0140343B1 - Interface circuit and method to reduce receiving error of remote control signal - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

Receive Remote Control Signal

2. The technical problem to be solved by the invention

Minimize the error when receiving the remote control signal

3. Summary of the Solution of the Invention

Detects the variations of the remote control signal, calculates the period of the detected variations, and compares the period between the calculated variations with preset reference times, and the period of the variation meets the range of reference times in the comparison analysis process. If it does, it handles with normal remote control signal, otherwise it handles error.

4. Important uses of the invention

Receives a remote control signal to minimize the reception error in the device controlling the device

Description

Interface circuit and method for reducing reception error of remote control signal

1 is a conventional circuit diagram for interfacing a remote control signal.

FIG. 2A is a waveform diagram of each of the first and second sub-waves when receiving a normal remote control signal. FIG.

3 is a circuit diagram of the present invention for interfacing a remote control signal.

FIG. 4A is an operation waveform diagram of each part of FIG. 3 when receiving a normal remote control signal. FIG. 4B is an operation waveform diagram of each part of FIG. 3 when an error remote control signal is received.

* Explanation of symbols for main parts of the drawings

111: receiver 112: general-purpose central processing unit

113: memory 114: timer

121-123: Inverter

The present invention relates to an interface circuit and method of a remote control signal, and more particularly, to a circuit and a method capable of accurately processing a remote control signal by analyzing a state of the remote control signal.

In general, the operation of home appliances such as televisions is controlled remotely using a remote controller. At this time, most home appliances that perform remote control minimize reception errors by using a dedicated microcomputer with an infrared remote control interface. However, the situation is different for products that use a general-purpose central processing unit. That is, the receiving side receives a remote control signal generated from a remote controller transmitter as an interrupt signal, and the general-purpose central processing unit receives a falling edge or a rising edge of the remote control signal. Only one variation can be selected as the interrupt signal.

FIG. 1 is a conventional remote control signal interface circuit diagram. Referring to the operation of the remote control signal processing process with reference to the operation waveform diagram of FIG. 2A, the remote control signal generated from the remote control transmitter is converted into an electrical signal at the receiver 111. Waveform shaping is performed at the digital level as shown in 211 of FIG. 2A. The remote control signal outputting the receiver 111 is inverted through the inverter 115 and then applied to the interrupt terminal of the general purpose CPU 112.

Accordingly, the general purpose CPU 112 receives falling edges of the remote control signal as shown in 211 of FIG. 2A as an interrupt signal as shown in 212. In addition, the general-purpose central processing unit 112 receives a timer signal of a predetermined period with a timer 114 and counts the falling transition period of the remote control signal. As shown in 211, the remote control signal has a different period between the high logic data and the low logic data. In general, the period is set so that data having arbitrary logic is N times that of data having other logic. It is assumed here that the data of the low logic has a period twice as long as the data of the high logic. Therefore, the general-purpose central processing unit 112 counts the periods of falling transitions of the remote control signals to determine the logic as shown at 213 in FIG. 2A.

However, since the signal generated from the remote control transmitter is an infrared signal, noise components may be included by other lights such as fluorescent lamps. In this case, the receiving side should be able to determine the noise signal included in the remote control signal.

When the noise control components 250 and 251 are included in the remote control signal as shown in 221 of FIG. 2B, the general-purpose central processing unit 112 recognizes this as an interrupt signal even in the falling transitions of the noise components 250 and 251. In this case, the general-purpose central processing unit 112 determines the logic of the data by counting the time between the previous falling variation and the current falling variation. When the noise is included in the data period having a high logic as shown in 251, the general-purpose central processing unit 112 The processor may determine this as data having low logic, such as 223. This is because the general-purpose CPU 112 determines that the generation interval of the external interrupt signal is large and small by counting only the number of regular timer signals each time the interrupt occurs. Therefore, as shown in FIG. 2B, the high data can be determined as two low data by the noise 250 generated in the high data period.

Therefore, the conventional remote control signal interface method receives only one transition signal of the falling transition or the rising transition as an interrupt signal, so that if a noise component such as a jamming wave is included, the probability of misinterpreting it as other data is large. There was a problem that can perform this malfunction.

Accordingly, an object of the present invention is to provide a circuit and a method capable of accurately determining noise components included in a remote control signal by detecting variations of the remote control signal and counting the time between the variations.

Another object of the present invention is to detect the falling and rising variations of the received remote control signal, examine the time period between these variations to determine the logic of the data, and control the system by considering the pulse within the reference time as noise To provide an interface circuit and method of the remote control signal that can accurately perform.

In order to achieve the above objects, the present invention provides means for receiving a remote control signal, means for detecting a first variation of the remote control signal, means for detecting a second variation of the remote control signal, and a timer signal. And a reference time for determining whether an error occurs in the remote control signal, and receiving the first and second transitions as an interrupt signal and counting the timer signal when the interrupt signal is received. And a control means for calculating the time between the two, the control means compares the time between the variations with the reference time, and if the time between the variations is greater than the reference time as a result of the analysis is processed as a normal remote control signal And processing the error remote control signal within the reference time.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same parts in the figures represent the same reference signs wherever possible.

In the following description, numerous specific details are set forth in order to provide a more general understanding of the invention, such as first variation-second variation, first reference time T1-fourth reference time T4, and the like. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

As used herein, the term "first edge" refers to a falling edge of a remote control signal, and the term "second edge" refers to a rising edge of a remote control signal. It will be apparent to those skilled in the art that the first variation may be set as the rising variation of the remote control signal and the second variation as the falling variation.

In addition, the first reference time T1 is a reference time for determining the first logical data, the second reference time T2 is a reference time for determining the second logical data, and the third reference time T3 is the first logic. It is a reference time commonly used for data and second logical data. Therefore, the first logical data should be in the range of the first reference time T1 + the third reference time T3, and the second logical data should be in the range of the second reference time T2 + the third reference time T3.

Here, it is assumed that the first logical data means high logic data and the second logical data is low logic data.

3 is an interface circuit diagram of a remote control signal according to the present invention, and the receiver 111 receives an infrared signal of a remote control generated from a remote control transmitter. The receiver 111 converts the received infrared signal into an electrical signal and then converts it into a digital level remote control signal. The inverter 121 inverts the remote control signal as a first buffer and outputs the remote control signal to the first interrupt terminal INT1 set to detect the falling edge of the general-purpose central processing unit 112. Inverters 122 and 123, as the second buffer, non-invert the different remote control signals and output them to the second interrupt terminal INT2 set to sense the rising edge of the general-purpose CPU 112. Accordingly, the inverter 121 detects the first variation of the remote control signal and applies it to the general-purpose CPU 112 as a first interrupt signal, and the inverters 122 and 123 detect the second variation of the remote control signal. The second interrupt signal is applied to the processing apparatus 112. The timer 114 generates a timer signal of a predetermined period and outputs it as a timer interrupt signal of the general purpose CPU 112. The general-purpose central processing unit 112 receives the first and second transitions received as the first interrupt terminal and the second interrupt terminal as a first interrupt signal and a second interrupt signal, respectively, and receives the timer interrupt signal. . The general-purpose central processing unit 112 calculates the time between variations of the remote control signal by counting the time until the next interrupt signal is received when receiving the first interrupt signal or the second interrupt signal as the timer interrupt signal. The time between the calculated variations is compared with the predetermined reference times to determine the presence of noise and the logic of the data. The memory 113 stores a program of the general purpose CPU 112, and temporarily stores data generated while the program is being executed.

4A illustrates a process of determining data logic of the remote control signal received in FIG. 3 when a normal remote control signal is received. 4B illustrates a process in which components such as those of FIG. 3 determine noise components when a remote control signal including noise is received.

It is assumed here that the logic high data has two times the logic low data period as shown in FIGS. 4A and 4B. In addition, it is assumed that the low-to-high duty ratio of the pulse in the logic high data is 3: 1, and the low-to-high duty ratio of the pulse in the logic low data is 1: 1.

The receiver 111 converts the infrared signal generated from the remote control transmitter into an electrical signal, and then converts the infrared signal into a digital remote control signal as shown in 411 of FIG. 4a. Then, the inverter 121 inverts the remote control signal and applies the first transition, which is the falling transition of the remote control signal, as 412 of FIG. 4A to the general-purpose CPU 112 as the first interrupt signal set as the falling transition detection. Inverters 122 and 123 non-invert the remote control signal and apply a rising transition, which is a second variation of the remote control signal, as the second interrupt signal set to the rising edge detection in the general-purpose CPU 112 as shown in 413 of FIG. do.

Then, when receiving the first interrupt signal such as 412 or the second interrupt signal such as 413, the general-purpose central processing unit 112 counts the timer interrupt signal output from the timer 114 to calculate the time between mutations such as 412. do. In addition, the general-purpose CPU 112 analyzes the logic of the received data by comparing and analyzing the time values between the variations with the first reference time T1-the third reference time T3. In this case, the time from the first to the second transition of the remote control signal should satisfy the range of the first reference time T1 or the second reference time T2, and the time from the second to first variation of the remote control signal. Must satisfy the range of the third reference time T3. Therefore, the general-purpose CPU 112 has a period of the second interrupt signal in the first interrupt signal satisfying the first reference time T1 and a period of the first interrupt signal in the second interrupt signal is the third reference time T3. If is satisfied, the received remote control signal is determined as logic high data as shown at 415 in FIG. 4A. In addition, the general-purpose CPU 112 has a period of the second interrupt signal in the first interrupt signal satisfies the second reference time T2 and a period of the first interrupt signal in the second interrupt signal is the third reference time T3. If is satisfied, the received remote control signal is determined as logical low data as shown at 415 in FIG. 4A.

Looking at the operation process when the normal remote control signal includes a noise component as shown in 450 of FIG. 4b, the noise component such as 450 is the falling side as shown in 422 and 423 through the inverter 121 and the inverter 122-123 This and rising shifts are detected, and the shifts are applied to the general-purpose central processing unit 112 as a first interrupt signal and a second interrupt signal. Then, the general-purpose CPU 112 also receives the variation of the noise components as an interrupt signal, thereby counting the period of the noise component as shown in 424 by the timer interrupt signal. However, the period of the noise component such as 450 is shorter than the first reference time T1 to the third reference time T3 of the normal remote control signal. Unwanted noise signals can also be added and longer than the duty of a normal remote control signal. Therefore, the general purpose CPU 112 should be able to detect such noise signals.

In this case, when the period between the variations of the received remote control signal is less than or greater than the first reference time T1-the third reference time T3, the general purpose CPU 112 receives the received remote control signal as shown in 425 of FIG. 4B. Error handling That is, when the period of the received remote control signal is out of the range of reference times, the general purpose CPU 112 processes the received remote control signal in error.

Therefore, the general-purpose central processing unit 112 calculates the period between each variation of the received remote control signal, satisfies the first reference time T1-the third reference time T3, and when the pulse width of the regular standard is regular, it is normal data. If a remote control signal is received that is irregular and falls below or exceeds a predetermined standard pulse width, the received remote control signal is error processed. At this time, if the error processing the received remote control signal does not perform the corresponding control command, and thus waits for the reception of the remote control signal of the corresponding control command. Therefore, when receiving a remote control signal having a pulse width that is out of a certain rule, it can be determined as noise to prevent the malfunction of the system.

Claims (12)

A circuit for receiving a remote control signal, comprising: means for receiving a remote control signal, means for detecting a first variation of the remote control signal, means for detecting a second variation of the remote control signal, and a timer signal Means for generating a reference time for determining whether or not an error occurs in the remote control signal, receiving the first and second transition detection signals as an interrupt signal, and counting the timer signal when the interrupt signal is received. And control means for calculating the time between the variations, wherein the control means detects variations of the received remote control signal, compares the period of the detected variations with the reference times, and analyzes the variation period. If the time satisfies the range of reference times, it is processed as a normal remote control signal. An interface circuit of a remote control signal, wherein the call is error-processed. The interface circuit of claim 1, wherein the first shift of the remote control signal is a falling shift and the second shift is a rising shift. A circuit for receiving a remote control signal, comprising: a receiver for receiving a remote control signal, converting the signal into an electrical signal and shaping the waveform, a first buffer for detecting a first variation of the waveform shaped remote control signal, and the waveform shaping A second buffer for detecting a second variation of a remote control signal, a timer for generating a timer signal, and preset data of a first reference time to a third reference time, wherein the first and second variation detection signals And a general purpose central processing unit for counting the timer signal upon receiving the interrupt signal, and counting the period between the first and second variations in which the general purpose central processing unit is continuously received. If the period between the transitions satisfies the range of the first reference time to the third reference time, the controller processes the normal remote control signal and removes the range of the first reference time to the third reference time. After the interface circuit of the remote control signal, characterized in that the error processing a remote control signal. 4. The logic of claim 3, wherein the general-purpose CPU has a first logic when the time from the first variation to the second variation and the time from the second variation to the first variation are the first reference time and the third reference time, respectively. And determining the data as the second logical data when the time from the first variation to the second variation and the time from the second variation to the first variation are the second reference time and the third reference period, respectively. Remote control signal interface circuit. The interface circuit of a remote control signal according to claim 4, wherein the second reference time and the third reference time have the same time period. The method of claim 3, wherein the first interrupt terminal is set to a fall transition of the general-purpose central processing unit, and the falling transition of the remote control signal is reversed by inverting the waveform-shaped remote control signal. A first buffer that detects the first variation and outputs the first interrupt terminal to a first interrupt terminal; and a first interrupt terminal set to a rising variation of the general-purpose central processing unit, and non-inverts the waveform-controlled remote control signal. And a second buffer which detects a rising transition of a remote control signal as the second variation and outputs it to the second interrupt terminal. A method of receiving a remote control signal, the method comprising: receiving a remote control signal and performing waveform shaping into a digital signal, continuously detecting first and second variations of the digital remote control signal, and detecting the variation Comparing and analyzing the period between the variation and the reference time for determining whether there is an error, and processing the normal remote control signal when the period between the variation in the comparison analysis process satisfies the range of the reference time And error processing the received remote control signal when the time between the variations in the comparative analysis is out of the range of the reference times. 8. The method of claim 7, wherein the first shift is a falling shift of the digital remote control signal and the second shift is a rising shift of the digital remote control signal. A method for receiving a remote control signal using a general purpose central processing unit having a first reference time to a third reference time that is set in advance for determining whether there is a normal state, the first or second variations of the remote control signal are continuously The time between the detected variation and the previous variation by counting the time between the detected variation and the predetermined reference time and comparing the set reference times with each other; Normally processing the remote control signal when satisfying the time range, and error processing the remote control signal when the period between the variations in the comparison and analysis process is out of the range of the first reference time to the third reference time Interface method of the remote control signal, characterized in that consisting of a process. The method of claim 9, wherein the processing of the normal remote control signal comprises: the time from the first variation to the second variation and the time from the second variation to the first variation, respectively; The process of determining the time and date as the first logical data, and the time from the first variation to the second variation and the time from the second variation to the first variation are respectively the second reference time and the third reference time date and time. Interface method of a remote control signal, characterized in that the process of determining by the logic data. The method of claim 10, wherein the second reference time and the third reference time have the same time period. 12. The interface of a remote control signal according to any one of claims 9 to 11, wherein the first shift is a falling shift of the digital remote control signal and the second shift is a rising shift of the digital remote control signal. Way.