CN104570858B - The analog signal method of sampling and sampling system - Google Patents

Abstract

The invention discloses an analog signal sampling method, which comprises the following steps: a microprocessor performs initial setting; the microprocessor selects a PWM channel to output the generated hardware logic signal; after the analog-digital converter receives the hardware logic signal, the analog-digital The converter sends the collected sampling data to the DMA controller through the SPI interface; when the buffer of the DMA controller is full of sampling data, the DMA controller generates an interrupt signal, and sends the interrupt signal and sampling data to the microprocessor; the microprocessor Analyze and calculate the sampling data. The invention also discloses a sampling system. The invention starts the analog-to-digital converter to collect the sampling data after initializing and setting by micro-processing, and achieves the technical effect that the sampling process does not need to be controlled. At the same time, the microprocessor of the invention can realize high-speed sampling of analog signals, and achieve the technical effects of low cost, simplified system structure and low design difficulty.

Description

Analog signal sampling method and sampling system

technical field

The invention belongs to the field of signal acquisition, and in particular relates to an analog signal sampling method and a sampling system.

Background technique

At present, the analog signal sampling technology is widely used in communication equipment in the communication industry, therefore, various analog signal sampling methods appear.

And the existing main analog signal sampling method is: select DSP (Digital Signal Processing: Digital Signal Processor) and FPGA (Field programmable Gate Array: Field Programmable Gate Array) to use in conjunction with, carry out the high-speed sampling of analog signal, wherein FPGA is responsible for the control of the high-speed sampling process of analog signals, and DSP is responsible for the analysis and calculation of sampling data

Because the existing analog signal acquisition system needs both DSP and FPGA, it causes the technical problem of high cost of constructing the sampling system. At the same time, due to the need for FPGA to control the high-speed sampling process of the analog signal, it causes technical problems such as complex structure of the sampling system and high design difficulty.

To sum up, it is an urgent technical problem to seek a sampling system with low cost, simple structure and low design difficulty.

Contents of the invention

The main purpose of the present invention is to provide an analog signal sampling method and a sampling system to solve the technical problems of high cost, complex structure and difficult design in the existing sampling system.

In order to achieve the above object, the invention provides a kind of analog signal sampling method, it comprises the steps:

The microprocessor performs initial settings.

The microprocessor generates a hardware logic signal, and selects a PWM channel to output the hardware logic signal.

After the analog-to-digital converter receives the hardware logic signal, the analog-to-digital converter collects sampling data, and sends the sampling data to the DMA controller through the SPI interface.

When the buffer of the DMA controller is full of the sampled data, the DMA controller generates an interrupt signal, and sends the interrupt signal and the sampled data to the microprocessor.

The microprocessor analyzes and calculates the sampling data.

Preferably, the step of performing initialization setting by the microprocessor includes:

The microprocessor acquires timing parameters of the analog-to-digital converter, and sets the output frequency and duty cycle of the PWM module of the microprocessor according to the timing parameters.

The microprocessor sets parameters of the SPI interface.

The microprocessor sets the buffer size of the DMA controller.

Preferably, the microprocessor generates a hardware logic signal, and the step of selecting the PWM channel to output the hardware logic signal includes:

The microprocessor generates clock signals, sampling signals and channel switching signals.

The microprocessor selects different PWM channels, and outputs the clock signal, the sampling signal and the channel switching signal respectively according to the set output frequency and the duty cycle.

Preferably, after the analog-to-digital converter receives the hardware logic signal, the analog-to-digital converter collects sampled data, and sends the sampled data to the DMA controller through the SPI interface, including:

The analog-to-digital converter receives the clock signal, the sampling signal, and the channel switching signal that are differently sent through the PWM channel.

The analog-to-digital converter collects the sampling data according to the clock signal and the sampling signal.

The analog-to-digital converter sends the sampling data to the DMA controller through the SPI interface according to the channel switching signal.

Preferably, the step of analyzing and calculating the sampling data by the microprocessor includes:

The microprocessor judges whether the PWM module of the microprocessor is working normally according to the sampling data.

The microprocessor judges whether the analog-to-digital converter collects sampled data normally according to the sampled data.

In addition, in order to achieve the above object, the present invention also provides an analog signal sampling system, which includes a microprocessor, an analog-to-digital converter, and a DMA controller, and the microprocessor communicates with the analog-to-digital converter through a PWM channel connected, the analog-to-digital converter is connected to the DMA controller through the SPI interface, the microprocessor is connected to the DMA controller, and the microprocessor is used for initializing settings and also for generating hardware The logic signal and the selected PWM channel output hardware logic signals, and analyze and calculate the sampling data; the analog-to-digital converter is used to collect the sampling data; the DMA controller is used to store the sampling data and generate an interrupt signal.

Preferably, the microprocessor includes an acquisition module, a background processing module, a PWM module, a background communication module and a judging module.

The acquiring module is configured to acquire timing parameters of the analog-to-digital converter.

The background processing module is used to set the output frequency and duty cycle of the PWM module according to the timing parameters, is also used to set the parameters of the SPI interface, and is also used to set the buffer of the DMA controller size, as well as generating hardware logic signals and selecting PWM channels.

The background communication module is used to send the hardware logic signal to the analog-to-digital converter.

The judging module is used for judging whether the PWM module works normally and whether the analog-to-digital converter collects sampling data normally according to the sampling data.

Preferably, the background processing module includes a clock signal generation unit, a sampling signal generation unit, a channel switching signal generation unit, and a PWM channel selection unit.

The clock signal generating unit is configured to generate a clock signal.

The sampling signal generating unit is configured to generate a sampling signal.

The channel switching signal generating unit is configured to generate a channel switching signal.

The PWM channel selection unit is used to select a PWM channel according to a clock signal, a sampling signal or a channel switching signal.

Preferably, the analog-to-digital converter includes an analog-to-digital converter processing module and an analog-to-digital converter communication module.

The analog-to-digital converter processing module is configured to collect sampling data according to the clock signal and the sampling signal.

The analog-to-digital converter communication module is used for receiving the clock signal, the sampling signal and the channel switching signal, and for sending the sampling data to the DMA controller.

Preferably, the DMA controller includes a DMA controller processing module and a DMA controller communication module.

The DMA controller processing module is used to store the sampling data into a buffer, and to generate an interrupt signal.

The DMA controller communication module is used to receive the sampling data and send an interrupt signal to the microprocessor.

The invention starts the analog-to-digital converter to collect the sampling data after initializing and setting through the micro-processing, and achieves the technical effect that the sampling process does not need to be controlled. At the same time, the microprocessor of the invention can realize high-speed sampling of analog signals, and achieve the technical effects of low cost, simplified system structure and low design difficulty.

Instructions attached

Fig. 1 is the schematic flow chart of embodiment 1 of analog signal sampling method of the present invention;

Fig. 2 is a schematic flow chart of Embodiment 2 of the analog signal sampling method of the present invention;

Fig. 3 is a schematic flow chart of Embodiment 3 of the analog signal sampling method of the present invention;

Fig. 4 is a schematic flow chart of Embodiment 4 of the analog signal sampling method of the present invention;

Fig. 5 is a schematic flow chart of Embodiment 5 of the analog signal sampling method of the present invention;

6 is a schematic block diagram of Embodiment 6 of the analog signal sampling system of the present invention;

Fig. 7 is the functional module schematic diagram of embodiment 7 of the microprocessor in the analog signal sampling system of the present invention;

8 is a schematic diagram of functional modules of Embodiment 8 of the analog-to-digital converter in the analog signal sampling system of the present invention;

FIG. 9 is a schematic diagram of functional modules of Embodiment 9 of the DMA controller in the analog signal sampling system of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example 1

Referring to FIG. 1 , FIG. 1 is a schematic flowchart of Embodiment 1 of the analog signal sampling method of the present invention.

In embodiment 1, the present invention provides a kind of analog signal sampling method, it comprises the steps:

Step S10, the microprocessor performs initialization settings.

The microprocessor includes a PWM (Pulse Width Modulation: Pulse Width Modulation) module, an SPI (Serial Control Interface: Serial Peripheral Interface) interface, and a DMA (Direct Memory Access: Direct Memory Access) controller. The microprocessor sets parameters for the PWM module, SPI interface, and DMA controller, so that when the subsequent ADC (Analog-to-Digital Control Analog-to-Digital Converter) collects sampling data, the microprocessor does not need to control the sampling process. The technical effect of improving the processing effect of the microprocessor is achieved.

Step S11, the microprocessor generates a hardware logic signal, and selects a PWM channel to output the hardware logic signal.

After the microprocessor initialization setting operation is completed, the microprocessor generates hardware logic signals related to ADC sampling. At the same time, select the corresponding PWM channel to output hardware logic signals.

Since the present invention has carried out the initial setting operation of the PWM module through microprocessing, when the present invention outputs the hardware logic signal through the selected PWM channel, the output frequency and duty cycle of the output hardware logic signal meet the setting requirements. Therefore, the technical effect that the microprocessor does not need to control the sampling process is achieved.

Step S12, after the analog-to-digital converter receives the hardware logic signal, the analog-to-digital converter collects sampling data, and sends the sampling data to the DMA controller through the SPI interface.

When the analog-to-digital converter receives the hardware logic signal, it starts to collect the sampling data, and transmits the collected sampling data to the DMA controller through the SPI interface.

Because the microprocessor of the present invention has carried out the initial setting operation to the SPI interface, so, the sampling data transmitted to the DMA control through the SPI interface is all sampling data that meets the requirements, and the technology that further ensures that the sampling process does not need the microprocessor to be controlled Effect.

Step S13, when the buffer of the DMA controller is full of the sampled data, the DMA controller generates an interrupt signal, and sends the interrupt signal and the sampled data to the microprocessor.

When the buffer of the DMA controller is full of sampling data, the DMA controller generates an interrupt signal, and the DMA sends the interrupt signal to the microprocessor. After receiving the interrupt signal, the microprocessor receives the sampling data sent by the DMA controller.

Step S14, the microprocessor analyzes and calculates the sampled data.

After the microprocessor receives the sampling data sent by the DMA controller, it analyzes, calculates, and processes the sampling data.

The invention starts the analog-to-digital converter to collect the sampling data after initializing and setting through the micro-processing, and achieves the technical effect that the sampling process does not need to be controlled. At the same time, the microprocessor of the invention can realize high-speed sampling of analog signals, and achieve the technical effects of low cost, simplified system structure and low design difficulty.

Example 2

Referring to FIG. 2 , FIG. 2 is a schematic flowchart of Embodiment 2 of the analog signal sampling method of the present invention.

In embodiment 2, the steps are basically the same as those in the above embodiment 1, except that the step S10 includes:

Step S20, the microprocessor acquires timing parameters of the analog-to-digital converter, and sets the output frequency and duty cycle of the PWM module of the microprocessor according to the timing parameters.

The microprocessor obtains the timing parameters of the analog-to-digital converter, and then sets the output frequency and duty cycle of the PWM module according to the timing parameters, so that after the hardware logic signal generated by the microprocessor is output through the PWM channel, its output frequency and duty cycle Consistent with the set output frequency and duty cycle.

Step S21, the microprocessor sets the parameters of the SPI interface.

The microprocessor sets the parameters of the SPI interface, so that the sampling data received by the analog-to-digital converter and sent to the DMA controller through the SPI is the sampling data that meets the setting requirements, and the technical effect of filtering the sampling data that meets the setting requirements is achieved.

Step S22, the microprocessor sets the buffer size of the DMA controller.

The microprocessor sets the buffer size of the DMA controller, so that the microprocessor can determine the best time interval to analyze and calculate the sampling data according to the specific situation, and achieve the technology of speeding up the processing efficiency of the microprocessor Effect.

Example 3

Referring to FIG. 3 , FIG. 3 is a schematic flowchart of Embodiment 3 of the analog signal sampling method of the present invention.

In embodiment 3, the steps are basically the same as those in the above embodiment 2, except that the step S11 includes:

Step S30, the microprocessor generates a clock signal, a sampling signal and a channel switching signal.

After the initialization setting operation of the microprocessor is completed, the microprocessor generates a clock signal (ad_clock), a sampling signal (ad_start) and a channel switching signal (ad_sel).

Step S31, the microprocessor selects different PWM channels, and outputs the clock signal, the sampling signal and the channel switching signal respectively according to the set output frequency and the duty cycle.

The microprocessor outputs a clock signal (ad_clock) for selecting a PWM channel, and the output frequency and duty cycle of the clock signal are consistent with the output frequency and duty cycle of the PWM module set by the microprocessor.

The microprocessor outputs a sampling signal (ad_start) for selecting a PWM channel, and the output frequency and duty cycle of the sampling signal are consistent with the output frequency and duty cycle of the PWM module set by the microprocessor.

The microprocessor outputs a channel switching signal (ad_sel) for selecting a PWM channel, and the output frequency and duty cycle of the channel switching signal are consistent with the output frequency and duty cycle of the PWM module set by the microprocessor.

In the invention, the microprocessor selects different PWM channels to output different hardware logic signals, thereby achieving the technical effect of accelerating the transmission speed.

Example 4

Referring to FIG. 4 , FIG. 4 is a schematic flowchart of Embodiment 4 of the analog signal sampling method of the present invention.

In Embodiment 4, the steps are basically the same as those in Embodiment 3 above, except that the step S12 includes:

Step S40, the analog-to-digital converter receives the clock signal, the sampling signal and the channel switching signal sent through different PWM channels.

The analog-to-digital converter receives clock signals, sampling signals and channel switching signals sent through different PWM channels.

Step S41, the analog-to-digital converter collects the sampling data according to the clock signal and the sampling signal.

After the analog-to-digital converter receives the clock signal and the sampling signal, it starts to collect the sampling data.

Step S42, the analog-to-digital converter sends the sampling data to the DMA controller through the SPI interface according to the channel switching signal.

After the analog-to-digital converter receives the channel switching signal, it sends the collected sampling data to the DMA controller through the SPI interface.

Example 5

Referring to FIG. 5 , FIG. 5 is a schematic flowchart of Embodiment 5 of the analog signal sampling method of the present invention.

In Embodiment 5, the steps are basically the same as those in Embodiment 1 above, except that the step S14 includes:

Step S50, the microprocessor judges whether the PWM module of the microprocessor is working normally according to the sampling data;

Step S51, the microprocessor judges whether the analog-to-digital converter collects sampled data normally according to the sampled data.

The sampling data of the present invention includes the judgment data information of the PWM module and the judgment data information of the analog-to-digital converter.

The microprocessor judges whether the PWM module works normally by judging the data information of the PWM module, and achieves the technical effect of ensuring that the output frequency and duty cycle of the output hardware logic signal meet the setting requirements.

The microprocessor judges whether the analog-to-digital converter works normally by judging the data information of the analog-to-digital converter, and achieves the technical effect of knowing the working state information of the digital converter in real time.

Example 6

Referring to FIG. 6, FIG. 6 is a schematic block diagram of Embodiment 6 of the analog signal sampling system of the present invention.

In addition, in order to achieve the above purpose, Embodiment 6 of the present invention also provides an analog signal sampling system, which includes a microprocessor 1, an analog-to-digital converter 2, and a DMA controller 3. The microprocessor 1 and the analog The digital converter 2 is communicatively connected through the PWM channel 4, the analog-to-digital converter 2 is communicatively connected with the DMA controller 3 through the SPI interface 5, and the microprocessor 1 is communicatively connected with the DMA controller 3, The microprocessor 1 is used to initialize settings, and is also used to generate hardware logic signals and select the PWM channel 4 to output hardware logic signals, and to analyze and calculate the sampled data; the analog-to-digital converter 2 is used to collect the sampled data; The DMA controller 3 is used for storing sampling data and generating interrupt signals.

The microprocessor includes a PWM (Pulse Width Modulation: Pulse Width Modulation) module, an SPI (Serial Control Interface: Serial Peripheral Interface) interface, and a DMA (Direct Memory Access: Direct Memory Access) controller.

Microprocessor 1 sets parameters for PWM module, SPI interface, and DMA controller 3, so that when the subsequent ADC (Analog-to-Digital Control Analog-to-Digital Converter 2) collects sampling data, the microprocessing does not need to carry out the sampling process. control. The technical effect of improving the processing effect of the microprocessor 1 is achieved.

After the microprocessor initialization setting operation is completed, the microprocessor 1 generates hardware logic signals related to ADC sampling. At the same time, select the corresponding PWM channel to output hardware logic signals. Since the present invention has carried out the initial setting operation of the PWM module through microprocessing, when the present invention outputs the hardware logic signal through the selected PWM channel, the output frequency and duty cycle of the output hardware logic signal meet the setting requirements. Therefore, the technical effect that the microprocessor 1 does not need to control the sampling process is achieved.

When the analog-to-digital converter 2 receives the hardware logic signal, it starts to collect the sampling data, and transmits the collected sampling data to the DMA controller 3 through the SPI interface.

Because the microprocessor 1 of the present invention has carried out the initial setting operation to the SPI interface, so, the sampling data transmitted to the DMA control by the SPI interface is all sampling data that meets the requirements, and it is further guaranteed that the sampling process does not need the microprocessor 1 to control technical effect.

When the buffer of DMA controller 3 is full of sampling data, DMA controller 3 generates an interrupt signal, and DMA sends the interrupt signal to microprocessor 1. After microprocessor 1 receives the interrupt signal, it receives DMA controller 3 Sent sample data.

After the microprocessor 1 receives the sampling data sent by the DMA controller 3 , it performs analysis, calculation, and processing operations on the sampling data.

The present invention starts the analog-to-digital converter 2 to collect sampling data after initializing and setting by microprocessing, and achieves the technical effect that the sampling process does not need to be controlled. At the same time, the microprocessor 1 of the present invention can realize high-speed sampling of analog signals, achieving the technical effects of low cost, simplified system structure and low design difficulty.

Example 7

Referring to FIG. 7 , FIG. 7 is a schematic diagram of the functional modules of Embodiment 7 of the microprocessor in the analog signal sampling system of the present invention.

In Embodiment 7, the structure is basically the same as that of Embodiment 6 above, except that the microprocessor 1 includes an acquisition module 10 , a background processing module 12 , a PWM module 11 , a background communication module 14 and a judgment module 13 .

The acquiring module 10 is configured to acquire timing parameters of the analog-to-digital converter.

The acquisition module 10 of the microprocessor acquires the timing parameters of the analog-to-digital converter, and sends the parameters to the background processing module 12 of the microprocessor.

The background processing module 12 is used to set the output frequency and duty cycle of the PWM module 11 according to the timing parameters, is also used to set the parameters of the SPI interface, and is also used to set the buffer of the DMA controller The size of the area, as well as generating hardware logic signals and selecting PWM channels.

The background processing module 12 of the microprocessor 1 sets the output frequency and the duty ratio of the PWM module 11 according to the timing parameters, so that when the hardware logic signal generated by the microprocessor is output through the PWM channel, its output frequency and the duty ratio are the same as the set The output frequency is consistent with the duty cycle.

The background processing module 12 of the microprocessor 1 also sets the parameters of the SPI interface, so that the sampling numbers output through the SPI interface are all sampling data meeting the sampling requirements.

The background processing module 12 of microprocessor 1 is also provided with the size of the buffer zone of DMA controller, so that after a preset period of time, microprocessor analyzes and processes the sampled data sent by DMA controller, which improves the performance of microprocessing. The technical effect of the processor's processing efficiency.

The background communication module 14 is configured to send the hardware logic signal to the analog-to-digital converter.

The background processing module 12 of the microprocessor 1 generates hardware logic signals, and selects different PWM channels to output different hardware logic signals to the analog-to-digital converter.

The judging module 13 is configured to judge whether the PWM module 11 works normally and whether the analog-to-digital converter collects sampling data normally according to the sampling data.

The judging module 13 of the microprocessor 1 can judge whether the PWM module 11 works normally and whether the analog-to-digital converter normally collects the sampled data according to the sampled data during the process of analyzing and calculating the sampled data of the DMA controller.

Further, the background processing module 12 includes a clock signal generation unit 121 , a sampling signal generation unit 122 , a channel switching signal generation unit 123 , and a PWM channel selection unit 124 .

The clock signal generating unit 121 is configured to generate a clock signal.

The sampling signal generation unit 122 is configured to generate a sampling signal.

The channel switching signal generating unit 123 is configured to generate a channel switching signal.

The PWM channel selection unit 124 is configured to select a PWM channel according to a clock signal, a sampling signal or a channel switching signal.

The clock signal generating unit 121 of the background processing module 12 generates a clock signal.

The sampling signal generating unit 122 of the background processing module 12 generates the sampling signal.

The channel switching signal generating unit 123 of the background processing module 12 generates the channel switching signal.

The PWM channel selection unit 124 of the background processing module 12 selects different PWM channels to output clock signals, sampling signals and channel switching signals respectively.

Example 8

Referring to FIG. 8 , FIG. 8 is a schematic diagram of functional modules of Embodiment 8 of the analog-to-digital converter in the analog signal sampling system of the present invention.

In Embodiment 8, the structure is basically the same as that of Embodiment 6 above, except that the analog-to-digital converter 2 includes an analog-to-digital converter processing module 21 and an analog-to-digital converter communication module 22 .

The analog-to-digital converter processing module 21 is configured to collect sampling data according to the clock signal and the sampling signal.

The analog-to-digital converter communication module 22 is used for receiving the clock signal, the sampling signal and the channel switching signal, and for sending the sampling data to the DMA controller.

The analog-to-digital converter communication module 22 receives the clock signal, sampling signal and channel switching signal sent by the microprocessor.

After the analog-to-digital converter processing module 21 of the analog-to-digital converter 2 receives the clock signal and the sampling signal, it starts to collect the sampling data.

After collecting the collected data, the analog-to-digital converter processing module 21 transmits the sampled data according to the channel switching signal.

The analog-to-digital converter communication module 22 sends the collected data to the DMA controller through the SPI interface.

Example 9

Referring to FIG. 9 , FIG. 9 is a schematic diagram of functional modules of Embodiment 9 of the analog-to-digital converter in the analog signal sampling system of the present invention.

In Embodiment 9, the structure is basically the same as that of Embodiment 6 above, except that the DMA controller 3 includes a DMA controller processing module 31 and a DMA controller communication module 32 .

The DMA controller processing module 31 is configured to store the sampling data into a buffer and generate an interrupt signal.

The DMA controller communication module 32 is used for receiving the sampling data and sending an interrupt signal to the microprocessor.

The DMA controller communication module 32 receives the sampling data sent by the analog-to-digital converter, and the DMA controller processing module 31 stores the sampling data into a buffer.

When the buffer is full of the sampling data, the DMA controller processing module 31 generates an interrupt signal.

The DMA controller communication module 32 sends the interrupt signal to the microprocessor.

The microprocessor reads the sampled data in the buffer, and performs analysis and calculation on the sampled data.

The specific embodiments of the invention have been described in detail above, but they are only examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the invention are also within the scope of the present invention, therefore, equivalent transformations, modifications and improvements made without departing from the spirit and scope of the present invention etc., should be covered within the scope of the present invention.

Claims (8)

1. an analog signal sampling method, is characterized in that, it comprises the steps: The microprocessor carries out initialization setting; The microprocessor generates a hardware logic signal, and selects a PWM channel to output the hardware logic signal; After the analog-to-digital converter receives the hardware logic signal, the analog-to-digital converter collects sampling data, and sends the sampling data to the DMA controller through the SPI interface; When the buffer of the DMA controller is full of the sampled data, the DMA controller generates an interrupt signal, and sends the interrupt signal and the sampled data to the microprocessor; The microprocessor analyzes and calculates the sampling data; The steps for the microprocessor to initialize and set include: The microprocessor acquires timing parameters of the analog-to-digital converter, and sets the output frequency and duty cycle of the PWM module of the microprocessor according to the timing parameters; The microprocessor sets the parameters of the SPI interface; The microprocessor sets the buffer size of the DMA controller. 2. analog signal sampling method according to claim 1, is characterized in that, described microprocessor produces hardware logic signal, and selects the step of PWM channel output hardware logic signal, comprises: The microprocessor generates a clock signal, a sampling signal and a channel switching signal; The microprocessor selects different PWM channels, and outputs the clock signal, the sampling signal and the channel switching signal respectively according to the set output frequency and the duty cycle. 3. The analog signal sampling method according to claim 2, wherein after the analog-to-digital converter receives the hardware logic signal, the analog-to-digital converter collects sampling data, and passes the sampling data through The steps for sending the SPI interface to the DMA controller include: The analog-to-digital converter receives the clock signal, the sampling signal and the channel switching signal sent through different PWM channels; The analog-to-digital converter collects the sampling data according to the clock signal and the sampling signal; The analog-to-digital converter sends the sampling data to the DMA controller through the SPI interface according to the channel switching signal. 4. analog signal sampling method according to claim 1, is characterized in that, described microprocessor carries out the step of analyzing and calculating processing to described sampling data, comprises: The microprocessor judges whether the PWM module of the microprocessor is working normally according to the sampling data; The microprocessor judges whether the analog-to-digital converter collects sampled data normally according to the sampled data. 5. An analog signal sampling system is characterized in that it includes a microprocessor, an analog-to-digital converter, and a DMA controller, and the microprocessor and the analog-to-digital converter are connected through a PWM channel, and the analog-to-digital converter The converter communicates with the DMA controller through the SPI interface, and the microprocessor communicates with the DMA controller. The microprocessor is used for initializing settings, and also for generating hardware logic signals and selecting PWM channels. Output hardware logic signals, and analyze and calculate the sampled data; the analog-to-digital converter is used to collect the sampled data; the DMA controller is used to store the sampled data and generate an interrupt signal; The microprocessor includes an acquisition module, a background processing module, a PWM module, a background communication module and a judgment module; The acquiring module is configured to acquire timing parameters of the analog-to-digital converter; The background processing module is used to set the output frequency and duty cycle of the PWM module according to the timing parameters, is also used to set the parameters of the SPI interface, and is also used to set the buffer of the DMA controller size, as well as generating hardware logic signals and selecting PWM channels; The background communication module is used to send the hardware logic signal to the analog-to-digital converter; The judging module is used for judging whether the PWM module works normally and whether the analog-to-digital converter collects sampling data normally according to the sampling data. 6. The analog signal sampling system according to claim 5, wherein the background processing module comprises a clock signal generating unit, a sampling signal generating unit, a channel switching signal generating unit, and a PWM channel selection unit; The clock signal generating unit is configured to generate a clock signal; The sampling signal generating unit is configured to generate a sampling signal; The channel switching signal generating unit is configured to generate a channel switching signal; The PWM channel selection unit is used to select a PWM channel according to a clock signal, a sampling signal or a channel switching signal. 7. The analog signal sampling system according to claim 6, wherein the analog-to-digital converter comprises an analog-to-digital converter processing module and an analog-to-digital converter communication module; The analog-to-digital converter processing module is used to collect sampling data according to the clock signal and the sampling signal; The analog-to-digital converter communication module is used for receiving the clock signal, the sampling signal and the channel switching signal, and for sending the sampling data to the DMA controller. 8. analog signal sampling system according to claim 5, is characterized in that, described DMA controller comprises DMA controller processing module and DMA controller communication module; The DMA controller processing module is used to store the sampling data into a buffer, and to generate an interrupt signal; The DMA controller communication module is used to receive the sampling data and send an interrupt signal to the microprocessor.