CN110231786A - A kind of MCVF multichannel voice frequency switch - Google Patents

Abstract

The invention discloses a multi-channel audio switcher, which comprises a front display board, a CLED display unit, a button LED unit, a monitoring unit and an MCU control unit are arranged inside the front display board, and the button LED unit is used for selecting and displaying the current channel. There is a monitoring circuit inside the monitoring unit, and the monitoring circuit adopts the ES9023 chip, which is used to convert the input I2S audio signal into an analog audio signal. A multi-channel audio switcher according to the present invention has high time precision, supports analog or digital audio channel switching, adapts to analog audio system and digital audio system to switch audio channels at the same time, and completes analog audio to digital audio or digital audio at the same time The conversion of audio to analog audio, the multi-period control system can be set to adapt to multi-task switching work, the automatic positioning period does not need to be manually set when starting up, and provides the monitoring function of the current channel earphone and the LED display of the current audio amplitude to realize the intuitiveness of the current switching state Display, bring better prospects for use.

Description

A multi-channel audio switcher

technical field

The invention relates to the field of multi-channel audio switcher, in particular to a multi-channel audio switcher.

Background technique

With the continuous development of science and technology, my country's radio and television industry has achieved further development, and automated broadcasting has gradually become an inevitable trend in the development of broadcasting. In the past, engineers were often required to manually select audio channels when inserting advertisements and news programs. The time is not accurate enough, manual operation steps are cumbersome, etc. The equipment used to automatically switch audio channels in the past also has insufficient time accuracy and cannot meet the time accuracy requirements of synchronous broadcast switching. The equipment is too large and does not support mixed switching of analog and digital audio. etc., for this reason, we propose a multi-channel audio switcher.

Contents of the invention

The main purpose of the present invention is to provide a multi-channel audio switcher, which can effectively solve the problems in the background technology.

In order to achieve the above object, the technical scheme that the present invention takes is:

A multi-channel audio switcher, comprising a front display board, the inside of the front display board is provided with a CLED display unit, a button LED unit, a listening unit and an MCU control unit,

The button LED unit is used for selection and display of the current channel,

The monitoring unit is provided with a monitoring circuit inside, and the monitoring circuit adopts an ES9023 chip for converting the input I2S audio signal into an analog audio signal,

The MCU control unit is internally provided with an MCU control circuit, and the MCU control circuit adopts a STM32F107VCT6 chip,

External control interfaces RS232 and USB are connected to the front display board, and a switching interface control circuit board is also connected to the front display board.

Preferably, the switching interface control circuit board is provided with a standard clock unit, a selection control unit, an audio input processing unit and an audio output processing unit,

Both the standard clock unit and the selection control unit are connected to the front display panel, the audio input processing unit and the audio output processing unit are both connected to the front display panel through the selection control unit,

An antenna is connected to one side of the standard clock unit,

The upper end of the audio input processing unit is connected with a digital audio or analog audio input unit, and the upper end of the audio output processing unit is connected with a digital audio or analog audio output unit,

The digital audio or analog audio input unit includes a digital audio input circuit board and an analog audio input circuit board, and the digital audio or analog audio output unit includes a digital audio output circuit board and an analog audio output circuit board.

Preferably, the digital audio input circuit board is provided with a digital audio input circuit, and the digital audio input circuit consists of a sampling rate conversion integrated circuit CS8422 and peripheral devices (crystal oscillator, configuration circuit, etc.) to form an AES-to-serial audio I2S circuit.

Preferably, the analog audio input circuit board is provided with an analog audio input circuit, and the analog audio input circuit consists of PCM4420 and peripheral devices (crystal oscillator, configuration circuit, etc.) to form a differential analog audio to I2S audio circuit.

Preferably, the digital audio output circuit board is provided with a digital audio output circuit, and the digital audio output circuit is composed of DIT4192 chip peripheral devices (crystal oscillator, configuration circuit, etc.) to form an I2S audio to AES3 digital audio circuit.

Preferably, the analog audio output circuit board is provided with an analog audio output circuit, and the analog audio output circuit is composed of PCM1794 chip peripheral devices (crystal oscillator, configuration circuit, etc.) to form an I2S audio to differential analog audio circuit.

Preferably, the selection control unit is provided with a switching selection circuit, and the switching selection circuit is composed of multiple blocks (determined by the number of input channels) 74HC245 to perform gating control on multiple I2S audio signals. The enable terminals of multiple 74HC245 are connected to the GPIO pins of the MCU, and the output terminals of these multiple 74HC245 are connected to the output ports of the switching selection circuit. In the control software of the MCU, only one 74HC245 chip is in the enabled state. Complete a channel selection.

Compared with the prior art, the present invention has the following beneficial effects:

1. By setting the selection control unit, it has high time accuracy (switching time accuracy reaches 0.1 second), supports analog or digital audio channel switching, and simultaneously outputs analog differential audio and digital AES3 audio, which means it is simultaneously compatible with analog audio systems and digital audio systems Complete the conversion of analog audio to digital audio or digital audio to analog audio while switching the audio channel.

2. The multi-period control system can be set (8 time periods per day, 7 days a week) to adapt to multi-task switching work, and the automatic positioning time period does not need to be set manually.

3. Provide the monitoring function of the earphones of the current channel and the LED display of the current audio amplitude to realize the intuitive display of the current switching state. At the same time, it has USB and RS232 external communication interfaces to perfectly connect with the external control system.

The parts not involved in the device are the same as the prior art or can be realized by adopting the prior art.

Description of drawings

Fig. 1 is the overall system block diagram of a kind of multi-channel audio switcher of the present invention;

Fig. 2 is a partial system block diagram of a multi-channel audio switcher of the present invention;

Fig. 3 is the system block diagram of the front display board of a kind of multi-channel audio switcher of the present invention;

Fig. 4 is the system block diagram of the switch interface control circuit board of a kind of multi-channel audio switcher of the present invention;

Fig. 5 is a switching principle diagram of a multi-channel audio switcher according to the present invention.

Detailed ways

Embodiments of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Example 1

As shown in Figure 1-4, a multi-channel audio switcher includes a front display board, which is equipped with a CLED display unit, a button LED unit, a monitoring unit and an MCU control unit, and the button LED unit is used for the current channel. Selection and display, there is a monitoring circuit inside the monitoring unit, and the monitoring circuit adopts the ES9023 chip. The MCU control unit is equipped with an MCU control circuit inside, and the MCU control circuit adopts the STM32F107VCT6 chip, which runs fast, has sufficient storage capacity, and stable performance. By adopting the above technical solutions: the multi-time control system that can be set ( 7 days a week, 8 time periods per day) to adapt to multi-tasking switching work, and the automatic positioning time period does not need to be manually set when starting up.

The front display board is connected with an external control interface RS232 and USB, and the front display board is also connected with a switching interface control circuit board.

By adopting the above technical solution: providing the monitoring function of the earphone of the current channel and the LED display of the current audio amplitude to realize the intuitive display of the current switching state, and having a USB and RS232 external communication interface to perfectly connect with the external control system.

Example 2

As shown in Figure 1-5, a multi-channel audio switcher is provided with a standard clock unit, a selection control unit, an audio input processing unit, and an audio output processing unit on the switching interface control circuit board. The standard clock unit and the selection control unit are both It is connected to the front display panel, the audio input processing unit and the audio output processing unit are connected to the front display panel through the selection control unit, the standard clock unit is connected to the antenna on one side, and the upper end of the audio input processing unit is connected to the digital audio or analog audio input unit, the upper end of the audio output processing unit is connected with a digital audio or analog audio output unit, the digital audio or analog audio input unit includes a digital audio input circuit board and an analog audio input circuit board, and the digital audio or analog audio output unit includes a digital audio output circuit board with the analog audio output circuit board.

The digital audio input circuit board is provided with a digital audio input circuit, and the digital audio input circuit is composed of a sampling rate conversion integrated circuit CS8422 and peripheral devices (crystal oscillator, configuration circuit, etc.) to form an AES to serial audio I2S circuit.

The analog audio input circuit board is provided with an analog audio input circuit, and the analog audio input circuit is composed of PCM4420 and peripheral devices (crystal oscillator, configuration circuit, etc.) to form a differential analog audio to I2S audio circuit.

The digital audio output circuit board is provided with a digital audio output circuit, and the digital audio output circuit is composed of DIT4192 chip peripheral devices (crystal oscillator, configuration circuit, etc.) to form an I2S audio to AES3 digital audio circuit.

The analog audio output circuit board is provided with an analog audio output circuit, and the analog audio output circuit is composed of PCM1794 chip peripheral devices (crystal oscillator, configuration circuit, etc.) to form an I2S audio to differential analog audio circuit.

The selection control unit is provided with a switching selection circuit, and the switching selection circuit is composed of multiple blocks (determined by the number of input channels) 74HC245 to perform gating control on multiple I2S audio signals. The enable terminals of multiple 74HC245 are connected to the GPIO pins of the MCU, and the output terminals of these multiple 74HC245 are connected to the output ports of the switching selection circuit. In the control software of the MCU, only one 74HC245 chip is in the enabled state. Complete a channel selection.

It supports mixed input of analog audio and digital audio, and can choose to install an analog audio input interface hardware module or a digital audio input interface hardware module as an audio source for switching input channels. When choosing to install the digital audio interface hardware module, the external input interface of this channel has only one XLR interface. The professional digital audio interface chip (CS8422) is mainly used to convert the AES3 signal with an uncertain sampling rate into an I ² S audio signal with a fixed sampling rate. When choosing to install the analog-digital audio interface hardware module, the external input interface of this channel needs to have two XLR interfaces. The professional analog-to-digital conversion chip ADC (PCM4220) is mainly used to convert the balanced analog audio into a fixed sampling rate I2S audio signal.

It supports simultaneous output of analog audio and digital audio, which is convenient for docking with audio transmission equipment with different interfaces in the broadcast transmitter room. The one-way I ² S signal output by the switching circuit is divided into two and simultaneously sent to the digital audio output module and the analog audio output module. When outputting analog audio, it mainly uses a professional digital-to-analog conversion chip DAC (PCM1794) to convert the I ² S audio signal with a fixed sampling rate into a balanced analog audio output; when outputting digital audio, it mainly uses a professional digital audio output interface chip (DIT4192 ) converts the I ² S signal with a fixed sampling rate into an AES3 audio signal with a 48K sampling rate.

Switching principle: use 74HC245 bus control chip to control the gate of several input I ² S signals.

By adopting the above technical solution: the selected control unit has high time accuracy (switching time accuracy reaches 0.1 second), supports analog or digital audio channel switching, and outputs analog differential audio and digital AES3 audio at the same time, that is, simultaneously adapts to the analog audio system When switching the audio channel with the digital audio system, the conversion of analog audio to digital audio or digital audio to analog audio is completed at the same time.

In other fields, timing and positioning modules that support both GPS (Global Positioning System) and BDS (China Beidou Navigation System) are widely used in devices that require high-precision timing and positioning. This module is just beneficial to the automatic broadcasting in the broadcasting system, which better improves the time accuracy and synchronization performance of automatic audio channel switching in the broadcasting system transmission.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, some improvements and modifications can also be made, and these improvements and modifications should also be regarded as Within the protection scope of the present invention.

Claims (7)

1. a kind of MCVF multichannel voice frequency switch, including preceding display board, it is characterised in that: it is aobvious that the preceding display board is internally provided with CLED Show unit, key LED unit, monitoring unit and MCU control unit,

The key LED unit is used for the selection and display of current channel,

The monitoring unit is internally provided with monitoring circuit, and the monitoring circuit uses ES9023 chip, for what will be inputted I2S audio signal is converted into analog audio signal,

The MCU control unit is internally provided with MCU control circuit, and the MCU control circuit uses STM32F107VCT6 core Piece,

It is connected with external control interface RS232 and USB on the preceding display board, is also connected with switching interface on the preceding display board Control circuit board.

2. a kind of MCVF multichannel voice frequency switch according to claim 1, it is characterised in that: the switching interface control circuit board On be provided with standard time clock unit, selection control unit, audio input process unit and audio output processing unit,

The standard time clock unit is connect with preceding display board with selection control unit, the audio input process unit and audio Output processing unit passes through selection control unit and connect with preceding display board,

The side of the standard time clock unit is connected with antenna,

The upper end of the audio input process unit is connected with digital audio or analog audio input unit, at the audio output The upper end of reason unit is connected with digital audio or analogue audio frequency output unit,

The digital audio or analog audio input unit include digital audio incoming line plate and analog audio input wiring board, The digital audio or analogue audio frequency output unit include digital audio output circuit board and analogue audio frequency output circuit board.

3. a kind of MCVF multichannel voice frequency switch according to claim 2, it is characterised in that: the digital audio incoming line plate On be provided with digital audio input circuit, the digital audio input circuit is by sample rate converter ic CS8422 and periphery Device (crystal oscillator, configuration circuit etc.) constitutes AES and turns serial audio I2S circuit.

4. a kind of MCVF multichannel voice frequency switch according to claim 2, it is characterised in that: the analog audio input wiring board On be provided with analog audio input circuit, the analog audio input circuit is by PCM4420 and peripheral components (crystal oscillator, configuration electricity Road etc.) constitute difference analogue audio conversion I2S voicefrequency circuit.

5. a kind of MCVF multichannel voice frequency switch according to claim 2, it is characterised in that: the digital audio output circuit board On be provided with digital audio output circuit, the digital audio output circuit is by DIT4192 chip periphery device (crystal oscillator, configuration Circuit etc.) constitute I2S audio conversion AES3 digital audio circuit.

6. a kind of MCVF multichannel voice frequency switch according to claim 2, it is characterised in that: the analogue audio frequency output circuit board On be provided with analogue audio frequency output circuit, the analogue audio frequency output circuit is by PCM1794 chip periphery device (crystal oscillator, configuration Circuit etc.) constitute I2S audio conversion difference analogue voicefrequency circuit.

7. a kind of MCVF multichannel voice frequency switch according to claim 2, it is characterised in that: be arranged in the selection control unit There is switching selecting circuit, the switching selecting circuit is made of muti-piece (input channel quantity determines) 74HC245 to multichannel I2S sound Frequency signal carries out gating control.The enable end of muti-piece 74HC245 is all connected with the GPIO pin of MCU, this muti-piece 74HC245's is defeated Outlet is connected on the output port of switching selecting circuit, only one 74HC245 chip is in the control software of MCU Enabled state can complete the selection in a channel.