KR19990075115A - Noise reduction method of volume control device using encoder - Google Patents

Abstract

The noise removing method of the volume control device using the disclosed encoder is to remove the noise generated by the mechanical characteristics of the encoder by using the minimum time that the pulse is continuously generated according to the revolutions per minute of the encoder.

According to the specification of the encoder used in the volume control device, an external interrupt pulse input when the interrupt source pulse is in a low level state after storing and setting the minimum time that pulses are continuously generated according to the revolutions per minute of the encoder. If is present, count the minimum time set, and judge whether there is another external interrupt pulse input while counting, recognize if there is noise and remove it, otherwise, if the minimum time is all counted It determines whether the external interrupt pulse input is high or low to raise or lower the volume output through the speaker.

Accordingly, the present invention provides an effect that the malfunction of the microprocessor can be prevented by removing noise generated from the mechanical characteristics of the encoder when controlling the volume control using the encoder.

Description

Noise reduction method of volume control device using encoder

The present invention relates to a noise removing method of a volume control device using an encoder, and more particularly, to remove noise generated by the mechanical characteristics of an encoder by using a minimum time that pulses are continuously generated according to the revolutions per minute of the encoder. It relates to a noise removing method of the volume control device using an encoder.

In general, the volume control device in the conventional audio output device employing a digital method, when a user or the like manipulates the volume adjusting means to adjust the volume, one or more predetermined pulse signals are output from the volume adjusting means. This output pulse was controlled to be synthesized with the audio signal, converted to an analog signal, amplified, and then output to the final audio signal through the speaker.

1 is a schematic block diagram for explaining the configuration of a volume control apparatus according to the prior art.

The encoder 1 has a rotary knob (not shown) for turning the user clockwise and counterclockwise when adjusting the volume, a reference terminal connected to ground, and a first output terminal to which power is applied ( OUT1) and a second output terminal OUT2.

The encoder 1 is selectively connected to the reference terminal with a phase difference of 90 ° between the first output terminal OUT1 and the second output terminal OUT2 as the user rotates the rotary knob.

Therefore, the encoder 1 outputs a pulse having a phase difference of 90 ° to each of the first output terminal OUT1 and the second output terminal OUT2 according to the direction in which the user rotates, and the encoder 1 also outputs the user. Outputs a pulse whose period is varied according to the speed at which the rotary knob is rotated to the first output terminal OUT1 and the second output terminal OUT2.

The microcomputer 2 outputs a pulse output from the encoder 1 by a reference source pulse, which is a clock signal according to the oscillation of the crystal oscillator (not shown in the drawing), from the first input terminal IN1 and the second input terminal ( It receives the input through IN2) and determines whether the user increases or decreases the volume, and outputs a volume control control signal to the volume controller 3.

The conventional volume control device configured as described above allows the user to rotate the rotary knob of the encoder 1 clockwise when increasing the volume output in the state where power is applied.

Then, the encoder 1 outputs a pulse signal to the first output terminal OUT1 as shown in FIG. 2A, and the phase is higher than the pulse signal output to the first output terminal OUT1 to the second output terminal OUT2. This 90 ° late pulse signal is output as shown in Fig. 2B.

That is, when the user rotates the rotary knob of the encoder 1 at a high speed, the period of the pulse signal output to the first output terminal OUT1 and the second output terminal OUT2 becomes short, and the encoder 1 When the rotary knob is rotated at a slow speed, the period of the output pulse signal becomes long.

By the pulse generated by the encoder 1 described above, the microcomputer 2 determines whether the user raises or lowers the volume of the volume output device, and accordingly, the volume control unit 3 controls the volume. By outputting the signal, the size of the audio signal output to the outside is amplified and output in a loud sound or reduced and output in a small sound.

However, since the first and second output terminals of the encoder according to the prior art are directly connected to the input terminals of the microcomputer, noise such as chattering generated when the encoder contacts are connected and opened when the encoder is rotated is generated in the microcomputer. There is a problem that the microcomputer may malfunction due to the input.

Accordingly, an object of the present invention is to adjust the volume using the encoder to remove the noise caused by the mechanical characteristics of the encoder by using the minimum time the pulse is continuously generated according to the number of revolutions of the encoder to solve the above problems The present invention provides a method for removing noise of a device.

1 is a schematic block diagram for explaining the configuration of a volume control apparatus according to the prior art,

2 is a view showing an output waveform according to the rotation direction of a typical encoder,

Figure 3 is a schematic block diagram for explaining the configuration of the volume control device according to the present invention,

4 is a diagram illustrating that noise is generated in an output waveform according to a rotation direction of an encoder;

5 is an operation flowchart for realizing a noise removing method of the volume control device using the encoder according to the present invention.

* Description of Signs of Main Parts of Drawings *

10: encoder

20 microprocessor

In the noise removing method of the volume control device using the encoder according to the present invention for achieving the above object, the present invention refers to the specifications of the encoder used in the volume control device pulses continuously according to the number of revolutions of the encoder After setting and saving the minimum time that occurs, if the interrupt source pulse is low level, if the external interrupt pulse is input, count the minimum time set and if there is another external interrupt pulse input while counting. If it is present, it recognizes that it is noise and removes it. Otherwise, after the minimum time is counted, it determines whether the external interrupt pulse is high or low to raise or lower the volume output through the speaker. It features.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is a schematic block diagram for explaining the configuration of the volume control device according to the present invention.

As shown, the encoder 10 is the same as the prior art and its configuration will not be described in detail.

The microcomputer 20 determines whether the first interrupt pulse IN1 and the second interrupt pulse IN2 are continuously input from the encoder 10 when the interrupt source pulse is at a low level. When the set minimum time is counted and another interrupt pulse inputted while counting is input, it is recognized as a noise and the volume control signal is not output to the volume controller 30.

4 is a diagram illustrating that noise is generated in an output waveform according to a rotation direction of an encoder.

As shown, noise may be generated in a normal pulse for adjusting the volume according to the mechanical operating characteristics of the encoder 10.

The operation of the volume control device using the encoder according to the present invention configured as described above will be described in more detail with reference to the accompanying drawings.

5 is an operation flowchart for realizing a noise removing method of the volume control device using the encoder according to the present invention.

As shown, first, in the internal memory (not shown) of the microcomputer 20, a minimum time for continuously generating interrupt pulses according to the revolutions per minute of the encoder is set.

Thereafter, the microcomputer 20 initializes the system (S510) to switch to the automatic noise removing mode for removing the noise generated by the encoder 10, performs the initialization step (S510), and then the microcomputer 20 In step S520, it is determined whether or not the interrupt source pulse input to the low level state.

As a result of the determination in step S520, when the interrupt source pulse is in the low level state, it is determined whether the first and second interrupt pulses are input from the encoder 10 (S530), and as a result, the first and second interrupt pulses are input. If the counting time set in the internal memory (S540).

While counting the time set in step S540, it is determined whether another interrupt pulse is input from the encoder 10 (S550), and as a result of the determination of step S550, counting when another interrupt pulse is input. It is determined whether the time matches the set time (S560).

As a result of the determination in step S560, when the counting time and the set time coincide with each other, it is determined whether the first interrupt pulse, which is the reference interrupt pulse, is a high level state by recognizing that it is an interrupt pulse for volume adjustment (S570). If it is determined that the counting time and the set time do not match, it is recognized that the noise is ignored (S580).

As a result of the determination in step S570, when the first interrupt pulse is in the high level state, a volume control uppulse for raising the volume is generated (S590) and output to the volume controller 30, and as a result of the determination in step S570, When the 1 interrupt pulse is in the low level state, a volume control down pulse for lowering the volume is generated (S600) and output to the volume controller 30.

Accordingly, as described above, the present invention provides an effect of preventing malfunction of the microprocessor by removing noise generated from the mechanical characteristics of the encoder when controlling the volume control using the encoder.

Claims (2)

A first step of initializing to switch to an automatic noise removing mode for removing noise generated by the encoder; A second step of determining whether an interrupt source pulse input after performing the first step is in a low level state; A third step of determining whether the first and second interrupt pulses are input from the encoder when the low level state is determined as the second step; A fourth step of counting a time set in an internal memory when an interrupt pulse is input as a result of the determination of the third step; A fifth step of determining whether another interrupt pulse is input from the encoder while counting the time set in the fourth step; A sixth step of determining whether a counting time and a set time coincide when another interrupt pulse is input as a result of the determination in the fifth step; A seventh step of determining whether the first interrupt pulse, which is the reference interrupt pulse, is a high level state by recognizing that the interrupt pulse is for volume control when the counting time and the set time coincide; An eighth step of recognizing and ignoring noise if the counting time and the set time do not match as a result of the determination of the sixth step; A ninth step of generating a volume control uppulse to increase the volume when the first interrupt pulse is in the high level state as a result of the determination in the seventh step; And And a tenth step of generating a volume control downpulse for lowering the volume when the first interrupt pulse is in a low level state as a result of the determination in the seventh step. The method of claim 1, wherein the time set in the internal memory of the fourth step is; Noise canceling method of a volume control device using an encoder characterized in that the minimum time that the interrupt pulse continuously occurs according to the number of revolutions of the encoder.