阅读说明：本技术 一种带控制电路智能音箱 (Intelligent sound box with control circuit ) 是由 庄建龙 李和娟 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种带控制电路智能音箱,包括MIC电路、外围接口、双声道蓝牙模块、电源电路、人机界面、外接SD卡接口、外接FLASH模块、功放电路和FM电路；所述双声道蓝牙模块内部集成MCU,所述功放电路中FM收集到的信号,通过双功放电路,将信号整理后发给MCU,MIC电路接收音频信号输出给MCU,MCU将处理好的信号通过FM发送出去或通过功放电路放大,然后由喇叭播放出去；本发明通过测量ADKEY的模拟信号,调整模式,FM收集的信号通过双功放电路将信号整理后发送给MCU处理,能够通过数字麦克风控制蓝牙数据和FM音频及电路预警的信号输出,采用RTC6218 FM收音芯片,增加收听广播功能,具有良好的市场应用价值。(The invention discloses an intelligent sound box with a control circuit, which comprises an MIC circuit, a peripheral interface, a dual-track Bluetooth module, a power circuit, a human-computer interface, an external SD card interface, an external FLASH module, a power amplifier circuit and an FM circuit, wherein the power circuit is connected with the external SD card interface; the dual-track Bluetooth module is internally integrated with an MCU, signals collected by FM in the power amplifier circuit are processed by the dual-power amplifier circuit and then sent to the MCU, the MIC circuit receives audio signals and outputs the audio signals to the MCU, and the MCU sends out the processed signals through FM or amplifies the processed signals through the power amplifier circuit and then broadcasts the signals through a loudspeaker; according to the invention, by measuring analog signals of ADKEY and adjusting the mode, signals collected by FM are processed by the double power amplifier circuit and then sent to the MCU for processing, Bluetooth data, FM audio and circuit early warning signal output can be controlled by the digital microphone, the RTC6218FM radio chip is adopted, the function of listening to broadcast is increased, and the invention has good market application value.)

1. An intelligent sound box with a control circuit is characterized by comprising an MIC circuit, a peripheral interface, a dual-track Bluetooth module, a power circuit, a human-computer interface, an external SD card interface, an external FLASH module, a power amplifier circuit and an FM circuit; the dual-track Bluetooth module is internally integrated with an MCU, signals collected by FM in the power amplifier circuit are processed by the dual-power amplifier circuit and then sent to the MCU, the MIC circuit receives audio signals and outputs the audio signals to the MCU, and the MCU sends out the processed signals through FM or amplifies the processed signals through the power amplifier circuit and then broadcasts the signals through a loudspeaker; an earphone and a USB interface are reserved on the peripheral interface, the power circuit is used for supplying power to the sound box during the charging period of the sound box through the USB interface or the USB interface directly supplies power to the sound box, and the human-computer interface is used for measuring analog signals of ADKEY and adjusting modes; the FM circuit adopts an RTC6218FM radio chip to add the function of listening to the broadcast.

2. The smart sound box with control circuit of claim 1, wherein the type of the integrated chip U2 is CW6631B SSOP28, and pin 25 and pin 23 of the integrated chip U2 are connected in series with the first end and the second end of the capacitor C31.

3. The intelligent sound box with the control circuit according to claim 1, wherein the two-channel Bluetooth module comprises an integrated chip U2, capacitors C4-C13, inductors L2-L4 and a crystal oscillator tube Y1; pin three and pin five of the integrated chip U2 are respectively connected to the second end of the capacitor C4 and the second end of the capacitor C9, pin 4 of the integrated chip U2 is respectively connected to the first ends of the capacitor C4 and the capacitor C9, the first ends of the capacitors C5, C6, C8, C10, C11 and C13 are sequentially and correspondingly connected to pins 25, 24, 23, 22, 19 and 16 of the integrated chip U2, pin 21 of the integrated chip U2 is respectively connected to the first end of the crystal oscillator tube Y1 and the first end of the capacitor C7, pin 20 of the integrated chip U7 is respectively connected to the second end of the crystal oscillator tube Y7 and the first end of the capacitor C7, the second ends of the capacitors C7 and C7 are both grounded, the inductors L7 and L7 are connected in parallel to both ends of the inductor L7, the first end of the inductor L7 is connected to the pin 17 of the integrated chip U7, and the second ends of the inductor L7 are both grounded.

4. The intelligent sound box with the control circuit as claimed in claim 1, wherein the power circuit comprises a USB1 and a hard switch circuit, pin 1 of the USB1 is connected with a charging indicator lamp circuit, pins 2 and 4 of the USB1 are connected with pin AUX of an integrated chip U2, pins 3 and 5 of the USB1 are connected with a power BT1, the power BT1 provides a voltage of 3.4V-4.2V for the power circuit, the charging indicator lamp circuit is composed of diodes D2, D3 and a transistor Q1, a base of the transistor Q1 is connected with a first end of a resistor R14, a collector of the transistor Q1 is connected with an anode of a diode D3, an emitter of the transistor Q1 is connected with pin 1 of the USB1, and the hard switch circuit is connected with pin 22 of the integrated chip.

5. The smart sound box with the control circuit according to claim 1, wherein the power amplifier circuit comprises an integrated chip U5 and an integrated chip U4, pins 1, 4 and 6 of the integrated chip U5 are respectively connected with pins 8, 7 and 22 of an integrated chip U2, pins 1 and 6 of the integrated chip U4 are respectively and correspondingly connected with pin 8 and pin 22 of an integrated chip U2, pin 8 and pin 5 of the integrated chip U5 are respectively and correspondingly connected with a first port and a second port of a connector J4, pin 4 of the integrated chip U4 is connected with a second end of a resistor R17 and a first end of a resistor R18, a second end of the resistor R18 is connected with a second end of the integrated chip U4, pin 4 of the integrated chip U5 is respectively connected with a first end of a resistor R38 and a second end of a resistor R37, a first end of the resistor R37 is connected in parallel with a capacitor C36, a capacitor C47 and a resistor R5, and a first end of the capacitor C36 is connected with a second end of a resistor R57324, the first end of the resistor R36 is respectively connected with the second ends of the capacitors C33 and C34, the first end of the capacitor C44 is connected with a pin 8 of an integrated chip U1, and the models of the integrated chips U4 and U5 are 8002A.

6. The intelligent sound box with the control circuit according to claim 1, wherein the reserved earphone and USB interface comprises a connector J2 and a USB2, a port 1 of the connector J2 is connected to a second end of a resistor R7 on the human-computer interface, ports 2, 3, and 4 of the connector J2 are respectively connected to a first end of a capacitor C35, a first end of a capacitor C14, and a ground, a second end of the capacitor C35 is connected to a pin 4 of an integrated chip U4, a second end of the capacitor C14 is connected to a first end of a capacitor C33, pins 1, 2, and 3 of the USB2 are correspondingly connected to pins 22, 27, and 26 of the integrated chip U2, and pins 4, 5, and 6 of the USB2 are all grounded.

7. The smart sound box with control circuit of claim 1, wherein the MIC circuit comprises a digital microphone M1, a capacitor C15, a capacitor C20 and a resistor R13; pin 5 and the first end of resistance R13 of integrated chip U2 are connected to the first end of electric capacity C15, the first end of electric capacity C20 and the first end of digital microphone M1 are connected respectively to the second end of resistance R13, pin 2 of integrated chip U2 is connected to the second end of electric capacity C20, the second end of digital microphone M1 and the second end of electric capacity C15 all ground, integrated chip U2's pin 9 and pin 25 are connected with the second end and the first end of resistance R1 on the human-computer interface respectively.

8. The smart sound box with the control circuit of claim 1, wherein the FM circuit comprises an integrated chip U1, an inductor L1, a capacitor C1, a capacitor C3 and a resistor R4; pin 1 of the integrated chip U1 is connected with the second end of a capacitor C1, the first end of the capacitor C1 is connected with the second end of an inductor L1, pin 6 of the integrated chip U1 is respectively connected with the second end of a capacitor C3 and the first end of a resistor R4, the first end of the capacitor C3 is grounded, the second end of the resistor R4 is connected with pin 25 of an integrated chip U2, and the type of the integrated chip U1 is RTC6218 or QN 8065.

9. The intelligent sound box with the control circuit as claimed in claim 1, wherein the external SD card interface comprises a connector J1, ports 3, 4, 5 and 7 of the connector J1 are respectively connected with pins 10, 25, 12 and 11 of an integrated chip U2, the external FLASH module comprises an integrated chip U3, pins 1, 2, 3 and 6 of the integrated chip U3 are respectively connected with pins 15, 13, 25 and 14 of an integrated chip U2, pin 5 of the integrated chip U3 is connected with pin 13 of the integrated chip U2, and the integrated chip U3 is an SPI FLASH.

Technical Field

The invention relates to the technical field of intelligent household equipment, in particular to an intelligent sound box with a control circuit.

Background

With the development of the smart home industry, many home hotels and some public service industries replace traditional devices with intelligent control devices, and in a conventional scheme, a control panel is mainly used, but with the development of a communication technology, a man-machine conversation is started by using intelligent sound box devices to realize intelligence. However, the existing intelligent control sound box has the problems that the sound amplification direction is uneven and resonance phenomenon is easy to occur, and electric crackling and screen flickering are easy to occur on the earphone, so that the existing technology has defects and needs to be improved.

Disclosure of Invention

The invention provides an intelligent sound box with a control circuit, which comprises an MIC circuit, a peripheral interface, a dual-track Bluetooth module, a power circuit, a human-computer interface, an external SD card interface, an external FLASH module, a power amplifier circuit and an FM circuit, wherein the power circuit is connected with the external SD card interface; the dual-track Bluetooth module is internally integrated with an MCU (microprogrammed control unit), signals collected by FM (frequency modulation) in the power amplifier circuit are processed by the dual power amplifier circuit and then sent to the MCU, the MCU controls an MIC (microphone) circuit to send FM audio, a digital microphone of the MIC circuit is used for outputting Bluetooth data, the FM audio and signals for circuit early warning, an earphone and a USB (universal serial bus) interface are reserved on the peripheral interface, the power circuit is used for supplying power to the sound box during the charging period of a USB (universal serial bus) port, or the USB directly supplies power to the sound box, and the man-machine interface is used for measuring analog signals of ADKEY and adjusting the mode; the FM circuit adopts an RTC6218FM radio chip to add the function of listening to the broadcast.

Preferably, the model of the integrated chip U2 is CW6631B SSOP28, and pin 25 and pin 23 of the integrated chip U2 are respectively and correspondingly connected to the first end and the second end of the capacitor C31.

Preferably, the two-channel Bluetooth module comprises an integrated chip U2, capacitors C4-C13, inductors L2-L4 and a crystal oscillator tube Y1; pin three and pin five of the integrated chip U2 are respectively connected to the second end of the capacitor C4 and the second end of the capacitor C9, pin 4 of the integrated chip U2 is respectively connected to the first ends of the capacitor C4 and the capacitor C9, the first ends of the capacitors C5, C6, C8, C10, C11 and C13 are sequentially and correspondingly connected to pins 25, 24, 23, 22, 19 and 16 of the integrated chip U2, pin 21 of the integrated chip U2 is respectively connected to the first end of the crystal oscillator tube Y1 and the first end of the capacitor C7, pin 20 of the integrated chip U7 is respectively connected to the second end of the crystal oscillator tube Y7 and the first end of the capacitor C7, the second ends of the capacitors C7 and C7 are both grounded, the inductors L7 and L7 are connected in parallel to both ends of the inductor L7, the first end of the inductor L7 is connected to the pin 17 of the integrated chip U7, and the second ends of the inductor L7 are both grounded.

Preferably, the power supply circuit comprises a USB1 and a hard switch circuit, pin 1 of the USB1 is connected with a charging indicator lamp circuit, pins 2 and 4 of the USB1 are connected with pin AUX of the integrated chip U2, pins 3 and 5 of the USB1 are connected with a power supply BT1, the power supply BT1 provides 3.4V-4.2V for the power supply circuit, the charging indicator lamp circuit is composed of diodes D2, D3 and a triode Q1, the base of the triode Q1 is connected with the first end of a resistor R14, the collector of the triode Q1 is connected with the positive electrode of the diode D3, the emitter of the triode Q1 is connected with pin 1 of the USB1, and the hard switch circuit is connected with pin 22 of the integrated chip.

Preferably, the power amplifier circuit comprises an integrated chip U5 and an integrated chip U4, pins 1, 4, and 6 of the integrated chip U5 are respectively connected to pins 2, 7, and 22 of an integrated chip U2, pins 1 and 6 of the integrated chip U4 are respectively and correspondingly connected to pin 2 and pin 22 of an integrated chip U2, pins 8 and 5 of the integrated chip U5 are respectively and correspondingly connected to a first port and a second port of a connector J4, pin 4 of the integrated chip U4 is connected to a second end of a resistor R17 and a first end of a resistor R18, a second end of the resistor R18 is connected to pin 5 of an integrated chip U4, pin 4 of the integrated chip U5 is respectively connected to a first end of a resistor R38 and a second end of a resistor R37, a first end of the resistor R9 is connected in parallel to a capacitor C36, a capacitor C47, and a resistor R34, a first end of the capacitor C36 is connected to a second end of the resistor R36, and a second end of the resistor R36 is connected to a capacitor C34, the first end of the capacitor C44 is connected with a pin 8 of an integrated chip U1, and the models of the integrated chips U4 and U5 are 8002A.

Preferably, the reserved earphone and USB interface includes a connector J2 and a US82, a port 1 of the connector J2 is connected to a second end of a resistor R7 on the human-computer interface, ports 2, 3, and 4 of the connector J2 are respectively connected to a first end of a capacitor C35, a first end of a capacitor C14, and ground, a second end of the capacitor C35 is connected to a pin 4 of an integrated chip U4, a second end of the capacitor C14 is connected to a first end of the capacitor C33, pins 1, 2, and 3 of the USB2 are correspondingly connected to pins 22, 27, and 26 of the integrated chip U2, and pins 4, 5, and 6 of the USB2 are all grounded.

Preferably, the MIC circuit comprises a digital microphone M1, a capacitor C15, a capacitor C20 and a resistor R13; pin 5 and the first end of resistance R13 of integrated chip U2 are connected to the first end of electric capacity C15, the first end of electric capacity C20 and the first end of digital microphone M1 are connected respectively to the second end of resistance R13, pin 2 of integrated chip U2 is connected to the second end of electric capacity C20, the second end of digital microphone M1 and the second end of electric capacity C15 all ground, integrated chip U2's pin 9 and pin 25 are connected with the second end and the first end of resistance R1 on the human-computer interface respectively.

Preferably, the FM circuit includes an integrated chip U1, an inductor L1, a capacitor C1, a capacitor C3, and a resistor R4; pin 1 of the integrated chip U1 is connected with the second end of a capacitor C1, the first end of the capacitor C1 is connected with the second end of an inductor L1, pin 6 of the integrated chip U1 is respectively connected with the second end of a capacitor C3 and the first end of a resistor R4, the first end of the capacitor C3 is grounded, the second end of the resistor R4 is connected with pin 25 of an integrated chip U2, and the type of the integrated chip U1 is RTC6218 or QN 8065.

Preferably, the external SD card interface includes a connector J1, ports 3, 4, 5, and 7 of the connector J1 are respectively connected to pins 10, 25, 12, and 11 of an integrated chip U2, the external FLASH module includes an integrated chip U3, pins 1, 2, 3, and 6 of the integrated chip U3 are respectively connected to pins 15, 13, 25, and 14 of an integrated chip U2, pin 5 of the integrated chip U3 is connected to pin 13 of the integrated chip U2, and the integrated chip U3 is an SPI FLASH.

Has the advantages that:

the invention can adjust the mode by measuring the analog signal of ADKEY, the signal collected by FM is processed by the double power amplifier circuit and then sent to the MCU for processing, the Bluetooth data, FM audio frequency and the signal output of circuit early warning can be controlled by the digital microphone, and the RTC6218FM radio chip is adopted, thereby increasing the function of listening to the broadcast.

Drawings

FIG. 1 is a circuit overall configuration diagram;

FIG. 2 is a circuit diagram of a dual channel Bluetooth module;

FIG. 3 is a circuit diagram of a power circuit;

FIG. 4 is a circuit diagram of a power amplifier circuit;

FIG. 5 is a diagram of a peripheral interface circuit configuration;

FIG. 6 is a circuit diagram of an MIC circuit;

FIG. 7 is a diagram showing the structure of an FM circuit;

FIG. 8 is a diagram of an external SD card interface circuit;

FIG. 9 is a circuit configuration diagram of an external FLASH module;

FIG. 10 is a human-machine interface circuit configuration diagram.

Detailed Description

In order to facilitate an understanding of the invention, the invention is described in more detail below with reference to the accompanying drawings and specific examples. The preferred embodiments of the present invention are shown in the drawings, but the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for descriptive purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The working method comprises the following steps:

the circuit measures the analog signal of ADKEY through the human interface, and adjusts the mode; adopt the integrated chip internal integration MCU, for MCU + bluetooth chip, come to control whole intelligent speaker through the bluetooth chip, the signal that FM was collected is through two power amplifier circuit arrangement backs simultaneously, with signal transmission for MCU, send the FM audio frequency by MCU control MIC circuit, simultaneously, pin VDDIO and RVDD at MCU concatenate the electric capacity and be used for eliminating on the earphone pop sound and the splash screen problem, signal output such as with bluetooth data and FM audio frequency and circuit early warning through digital microphone, still reserve earphone and USB interface on intelligent speaker simultaneously, switch charges for intelligent speaker through the USB interface during, the pilot lamp lights, or directly give intelligent speaker power supply through the USB interface, SD card is inserted to external SD screens, be used for playing the music function, the RTC6218FM radio chip of adoption, the function of listening to the radio has been increased.

The first embodiment is as follows:

as shown in fig. 1, an intelligent sound box with a control circuit comprises an MIC circuit, a peripheral interface, a dual-channel bluetooth module, a power circuit, a human-computer interface, an external SD card interface, an external FLASH module, a power amplifier circuit and an FM circuit; the dual-track Bluetooth module is internally integrated with an MCU (microprogrammed control unit), signals collected by FM (frequency modulation) in the power amplifier circuit are processed by the dual power amplifier circuit and then sent to the MCU, the MCU controls an MIC (microphone) circuit to send FM audio, a digital microphone of the MIC circuit is used for outputting Bluetooth data, the FM audio and signals for circuit early warning, an earphone and a USB (universal serial bus) interface are reserved on the peripheral interface, the power circuit is used for supplying power to the sound box during the charging period of a USB (universal serial bus) port, or the USB directly supplies power to the sound box, and the man-machine interface is used for measuring analog signals of ADKEY and adjusting the mode; the FM circuit adopts an RTC6218FM radio chip to add the function of listening to the broadcast.

As shown in fig. 1, the model of the integrated chip U2 is CW6631B SSOP28, and pin 25 and pin 23 of the integrated chip U2 are respectively connected to the first end and the second end of the capacitor C31; VDDIO is used to eliminate the headset power-up and splash screen problem, along with the RVDD series capacitor C31.

As shown in fig. 2, the two-channel bluetooth module includes an integrated chip U2, capacitors C4-C13, inductors L2-L4, and a crystal oscillator tube Y1; pin three and pin five of the integrated chip U2 are respectively connected to the second end of the capacitor C4 and the second end of the capacitor C9, pin 4 of the integrated chip U2 is respectively connected to the first ends of the capacitor C4 and the capacitor C9, the first ends of the capacitors C5, C6, C8, C10 are respectively and correspondingly connected to pins 25, 24, 23, 22, 19, 16 of the integrated chip U10, pin 21 of the integrated chip U10 is respectively connected to the first end of the crystal tube Y10 and the first end of the capacitor C10, pin 20 of the integrated chip U10 is respectively connected to the second end of the crystal tube Y10 and the first end of the capacitor C10, the second ends of the capacitors C10-C10 are both grounded, the inductors L10-L10 are connected in parallel to both ends of the inductor L10, the first end of the inductor L10 is connected to pin 17 of the integrated chip U10, the inductor L10 and the inductor L10 are both grounded according to frequency offset parameters of the frequency of the bluetooth frequency of the crystal tube C10, the bluetooth frequency tuning circuit b 10, the frequency of the bluetooth frequency tuning circuit b 10 is adjusted to the frequency of the bluetooth frequency of the frequency tuning circuit b 10, the crystal oscillator and the matching capacitor are arranged close to the chip.

As shown in fig. 3, the power circuit includes a USB1 and a hard switch circuit, pin 1 of the USB1 is connected to a charge indicator lamp circuit, pins 2 and 4 of the USB1 are connected with a pin AUX of an integrated chip U2, pins 3 and 5 of the USB1 are connected with a power supply BT1, the power supply BT1 provides 3.4V-4.2V voltage for the power circuit, the charging indicator lamp circuit consists of diodes D2, D3 and a triode Q1, the base of the triode Q1 is connected with the first end of the resistor R14, the collector of the triode Q1 is connected with the anode of the diode D3, the emitter of the triode Q1 is connected with pin 1 of the USB1, the hard switch circuit is connected with pin 22 of the integrated chip, whether the power supply circuit supplies power for the intelligent sound box is confirmed through the charging indicator light circuit, meanwhile, a hard switch circuit is also arranged, and power supply is controlled through a single-pole double-throw switch on the hard switch circuit.

As shown in fig. 4, the power amplifier circuit includes an integrated chip U5 and an integrated chip U4, pins 1, 4, and 6 of the integrated chip U5 are respectively connected to pins 2, 7, and 22 of an integrated chip U2, pin 1 and pin 6 of the integrated chip U4 are respectively and correspondingly connected to pin 2 and pin 22 of an integrated chip U2, pin 8 and pin 5 of the integrated chip U5 are respectively and correspondingly connected to a first port and a second port of a connector J4, pin 4 of the integrated chip U4 is connected to a second end of a resistor R17 and a first end of a resistor R18, a second end of the resistor R18 is connected to pin 5 of an integrated chip U4, pin 4 of the integrated chip U5 is respectively connected to a first end of a resistor R38 and a second end of a resistor R37, a first end of the resistor R9 is connected in parallel to a capacitor C36, a capacitor C47, and a resistor R34, a first end of the capacitor C36 is connected to the second end of the resistor R36, and a second end of the resistor R36 is connected to a capacitor C34, the first end of the capacitor C44 is connected with a pin 8 of an integrated chip U1, the models of the integrated chips U4 and U5 are 8002A, and an up-down pull resistor is selected according to high-low MUTE.

As shown in fig. 5, the reserved earphone and USB interface includes a connector J2 and a connector US82, a port 1 of the connector J2 is connected to a second end of a resistor R7 on the human-computer interface, ports 2, 3, and 4 of the connector J2 are respectively connected to a first end of a capacitor C35, a first end of a capacitor C14, and a ground, a second end of the capacitor C35 is connected to a pin 4 of an integrated chip U4, a second end of the capacitor C14 is connected to a first end of a capacitor C33, pins 1, 2, and 3 of the USB2 are correspondingly connected to pins 22, 27, and 26 of the integrated chip U2, and pins 4, 5, and 6 of the USB2 are all grounded.

As shown in fig. 6, the MIC circuit includes a digital microphone M1, a capacitor C15, a capacitor C20, and a resistor R13; pin 5 and the first end of resistance R13 of integrated chip U2 are connected to the first end of electric capacity C15, the first end of electric capacity C20 and the first end of digital microphone M1 are connected respectively to the second end of resistance R13, pin 2 of integrated chip U2 is connected to the second end of electric capacity C20, the second end of digital microphone M1 and the second end of electric capacity C15 all ground, integrated chip U2's pin 9 and pin 25 are connected with the second end and the first end of resistance R1 on the human-computer interface respectively.

As shown in fig. 7, the FM circuit includes an integrated chip U1, an inductor L1, a capacitor C1, a capacitor C3, and a resistor R4; pin 1 of the integrated chip U1 is connected with the second end of a capacitor C1, the first end of the capacitor C1 is connected with the second end of an inductor L1, pin 6 of the integrated chip U1 is respectively connected with the second end of a capacitor C3 and the first end of a resistor R4, the first end of the capacitor C3 is grounded, the second end of the resistor R4 is connected with pin 25 of an integrated chip U2, and the type of the integrated chip U1 is RTC6218 or QN 8065.

As shown in fig. 8, the external SD card interface includes a connector J1, ports 3, 4, 5, and 7 of the connector J1 are respectively connected to pins 10, 25, 12, and 11 of an integrated chip U2, the external FLASH module includes an integrated chip U3, pins 1, 2, 3, and 6 of the integrated chip U3 are respectively connected to pins 15, 13, 25, and 14 of an integrated chip U2, pin 5 of the integrated chip U3 is connected to pin 13 of the integrated chip U2, and the integrated chip U3 is an SPI FLASH.

Those not described in detail in this specification are within the skill of the art.

The technical features mentioned above are combined with each other to form various embodiments which are not listed above, and all of them are regarded as the scope of the present invention described in the specification; also, modifications and variations may be suggested to those skilled in the art in light of the above teachings, and it is intended to cover all such modifications and variations as fall within the true spirit and scope of the invention as defined by the appended claims.