CN213689719U

CN213689719U - Signal generator circuit based on STM32 singlechip

Info

Publication number: CN213689719U
Application number: CN202022974522.5U
Authority: CN
Inventors: 李志伟; 徐磊; 李强鑫; 汪向华; 卫宏; 宋芸
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Intrinsic Instruments Co ltd
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2021-07-13
Anticipated expiration: 2030-12-14

Abstract

The utility model discloses a signal generator circuit based on STM32 singlechip sends out the instruction through the button, and the singlechip accepts the instruction and controls peripheral circuit to produce the waveform signal of different types, different frequency and different duty cycles, draw the waveform of output on the display screen, demonstrate each item parameter of waveform etc. The signal generator circuit comprises an MAX038 signal generating circuit, an X9511 digital potentiometer circuit, a CD4051 digital switch circuit, a key circuit, a single chip microcomputer minimum system circuit, a TFT-LCD display circuit, a power supply conversion circuit and a signal conditioning circuit. The utility model sends different signal waveforms through the high-precision function signal generator, and selects the output waveform signal through the key control, the circuit is simple and reliable, the flexibility of waveform type selection is high, the output waveform signal is accurate and stable, and the anti-interference performance is good; the whole circuit has low power consumption and wide application applicability.

Description

Signal generator circuit based on STM32 singlechip

Technical Field

The utility model discloses can be applied to circuit experiment and equipment detection area, concretely relates to signal generator circuit based on STM32 singlechip.

Background

The signal generator is a signal source widely used in daily test, production and practice. The signal generator is one of important measuring instruments, and has wide application in production practice and technical fields. Especially in the technical fields of electrical engineering, communication engineering, automatic control, instruments and meters and the like, a signal generator for generating various waveforms is often needed, can meet various requirements of a test system, and becomes an indispensable component in the comprehensive test of the system. Due to the high price and single function of the special signal generator, the market demand of the signal generator is low in energy consumption, multifunctional and intelligent. Especially in scientific research, experiments and practices, the traditional low-frequency public signal source is composed of pure hardware circuits, and the performance of the traditional low-frequency public signal source cannot meet the actual requirements. The traditional waveform generator is realized by adopting an analog splitting element, the type of the generated waveform is limited by circuit hardware, and the flexibility and the stability are relatively poor.

Disclosure of Invention

The utility model aims to solve the technical problem that the utility model provides a signal generator circuit based on STM32 singlechip to the not enough of above-mentioned prior art, this signal generator circuit based on STM32 singlechip sends different signal waveforms through high accuracy function signal generator to select the waveform signal of output through key control, show the output waveform through TFT-LCD display circuit at last, whole circuit is simple and reliable, the selection of waveform type is simple and convenient, the flexibility is high, the output waveform signal is accurate, stable, interference immunity is good; the whole circuit has low power consumption and wide application applicability.

In order to realize the technical purpose, the utility model discloses the technical scheme who takes does:

a signal generator circuit based on an STM32 single chip microcomputer comprises an MAX038 signal generating circuit, an X9511 digital potentiometer circuit, a CD4051 digital switch circuit, a key circuit, a single chip microcomputer minimum system circuit, a TFT-LCD display circuit, a power supply conversion circuit and a signal conditioning circuit;

the MAX038 signal generating circuit, the X9511 digital potentiometer circuit, the CD4051 digital switch circuit, the key circuit, the TFT-LCD display circuit, the power supply conversion circuit and the signal conditioning circuit are all connected with the minimum system circuit of the single chip microcomputer, the X9511 digital potentiometer circuit, the CD4051 digital switch circuit and the signal conditioning circuit are all connected with the MAX038 signal generating circuit, and the MAX038 signal generating circuit, the X9511 digital potentiometer circuit, the CD4051 digital switch circuit, the key circuit, the minimum system circuit of the single chip microcomputer, the TFT-LCD display circuit and the signal conditioning circuit are all connected with the power supply conversion circuit.

As the further improved technical proposal of the utility model, the power supply conversion circuit comprises a WRA1205CKS-1W power supply module and an LM1117-3.3V voltage stabilizer;

a pin 1 of the WRA1205CKS-1W power supply module is connected with a ground wire, a pin 2 of the LM1117-3.3V voltage stabilizer is connected with a +12V power supply, a pin 6 of the LM1117-3.3V voltage stabilizer is connected with one end of a capacitor C23, a pin 8 of the LM1117-3.3V voltage stabilizer is connected with one end of a capacitor C22, and a pin 7 of the LM1117-3.3V voltage stabilizer is simultaneously connected with the other ends of the capacitor C23 and the capacitor C22; a pin 8 of the WRA1205CKS-1W power supply module is used for outputting a-5V power supply, and a pin 6 is used for outputting a +5V power supply;

pin 1 of LM1117-3.3V stabiliser connects the ground wire, LM1117-3.3V stabiliser's pin 2 connects +5V power, and pin 2 passes through electric capacity C24 and connects the ground wire, connects the ground wire through electric capacity C25, LM1117-3.3V stabiliser's pin 3 passes through electric capacity C26 and connects the ground wire, connects the ground wire through electric capacity C27, LM1117-3.3V stabiliser's pin 3 is used for exporting +3.3V power.

As a further improved technical scheme of the utility model, the minimum system circuit of singlechip adopts STMF103C8T6 singlechip, pin 9, pin 24, pin 36 and pin 48 of STM32F103C8T6 singlechip all connect +3.3V power, and this +3.3V power passes through electric capacity C2 and connects the ground wire, pin 47, pin 35, pin 23 and pin 8 of STM32F103C8T6 singlechip all connect the ground wire, pin 44 of STM32F103C8T6 singlechip connects the ground wire through resistance R11, pin 20 of STM32F103C8T6 singlechip connects the ground wire through resistance R12, pin 3 of STM32F103C8T6 singlechip is connected with electric capacity C8 one end and crystal oscillator Y1 one end simultaneously, the pin 4 of STM32F103C8T6 simultaneously with electric capacity C7 one end and crystal oscillator Y1 other end, electric capacity C6 and electric capacity C68642C 6 one end are connected with electric capacity C468 one end and crystal oscillator Y465 one end 4632C 468C 465 and crystal oscillator Y4632C 465 one end simultaneously the electric capacity C4632C 3 of singlechip is connected with electric capacity C3 one end simultaneously, The other end of the resistor R14 is connected with the other end of the crystal oscillator Y2, the other ends of the capacitor C11 and the capacitor C16 are both connected with the ground wire, a pin 7 of the STM32F103C8T6 single-chip microcomputer is connected with one end of a resistor R15, one end of a key S5 and one end of a capacitor C21, the other end of the resistor R15 is connected with a +3.3V power supply, the other ends of the key S5 and the capacitor C21 are both connected with the ground wire, and a pin 1 of the STM32F103C8T6 single-chip microcomputer is connected with the.

As a further improved technical scheme of the utility model, MAX038 signal generation circuit adopts MAX038 function generator, pin 3 of MAX038 function generator is connected with pin 18 of STMF103C8T6 singlechip, pin 4 of MAX038 function generator is connected with pin 38 of STMF103C8T6 singlechip, pin 7 of MAX038 function generator is connected with X9511 digital potentiometer circuit, pin 19 of MAX038 function generator is connected with signal conditioning circuit, a resistor MAX 13 is connected between pin 1 and pin 10 of MAX038 function generator, pin 5 of MAX038 function generator is connected with CD4051 digital switch circuit, pin 20 of MAX038 function generator is connected with-5V power supply and one end of capacitor C3 simultaneously, pin 17 of MAX038 function generator is connected with +5V power supply and one end of capacitor C5 simultaneously, the other end of capacitor C3 and capacitor C5 are connected with pin 18 of MAX038 function generator, and the pin 15, the pin 13, the pin 12, the pin 11, the pin 9, the pin 6 and the pin 2 of the MAX038 function generator are all connected with a ground wire.

As a further improved technical solution of the utility model, X9511 digital potentiometer is adopted to the X9511 digital potentiometer circuit, pin 1 of X9511 digital potentiometer is connected with pin 28 of STMF103C8T6 singlechip, pin 2 of X9511 digital potentiometer is connected with pin 27 of STMF103C8T6 singlechip, pin 3 of X9511 digital potentiometer connects +5V power, pin 4 of X9511 digital potentiometer connects the ground wire, pin 5 of X9511 digital potentiometer is connected with pin 7 of MAX038 function generator, pin 6 of X9511 digital potentiometer connects-5V power, pin 7 of X9511 digital potentiometer connects the ground wire, pin 8 of X9511 digital potentiometer connects +5V power through diode D1, and pin 8 connects the ground wire through electric capacity C1.

As a further improved technical scheme of the utility model, the CD4051 digital switch circuit adopts a CD4051 digital switch, pin 16 of the CD4051 digital switch is connected with a +5V power supply, pin 9 of the CD4051 digital switch is connected with pin 34 of the STMF103C8T6 singlechip, pin 10 of the CD4051 digital switch is connected with pin 33 of the STMF103C8T6 singlechip, pin 11 of the CD4051 digital switch is connected with pin 32 of the STMF103C8T6 singlechip, pin 6, pin 7 and pin 8 of the CD4051 digital switch are all connected with a ground wire, pin 4 of the CD4051 digital switch is connected with a ground wire through a capacitor C19 and a capacitor C20 in turn, pin 2 of the CD4051 digital switch is connected with a ground wire through a capacitor C18, pin 5 of the CD4051 digital switch is connected with a ground wire through a capacitor C17, pin 1 of the CD4051 digital switch is connected with a capacitor C14 and a capacitor C15 in turn, pin 12 of the CD4051 digital switch is connected with a ground wire through a capacitor C13, the pin 15 of the CD4051 digital switch is connected with the ground wire through a capacitor C12, the pin 14 of the CD4051 digital switch is connected with the ground wire through a capacitor C10, the pin 13 of the CD4051 digital switch is connected with the ground wire through a capacitor C8 and a capacitor C9 in sequence, and the pin 3 of the CD4051 digital switch is connected with the pin 5 of the MAX038 function generator.

As a further improved technical scheme of the utility model, the signal conditioning circuit adopts LM358 operational amplifier, pin 1 of LM358 operational amplifier is connected with resistance R7 and one end of slide rheostat RP1 simultaneously, the other end of resistance R7 is connected with pin 19 of STMF103C8T6 singlechip, the other end of resistance R7 is connected with ground through resistance R10, pin 4 of LM358 operational amplifier is connected with-5V power supply, pin 8 of LM358 operational amplifier is connected with +5V power supply, pin 2 of LM358 operational amplifier is connected with one end of resistance R5 simultaneously and the other end of slide rheostat RP1 and slide end simultaneously, the other end of resistance R5 is connected with ground, pin 3 of LM358 operational amplifier is connected with one end of resistance R9 and one end of resistance R6 simultaneously, the other end of resistance R9 is connected with the slide end of slide rheostat RP2, one end of slide rheostat 2 is connected with +5V power supply, the other end of the slide rheostat RP2 is connected with a-5V power supply, the other end of the resistor R6 is simultaneously connected with one end of a resistor R8, one end of a capacitor C4 and a pin 19 of the MAX038 function generator, and the other end of the resistor R8 and the other end of the capacitor C4 are both connected with a ground wire.

As a further improved technical solution of the present invention, the key circuit includes a key S1, a key S2, a key S3, a key S4, a resistor R1, a resistor R2, a resistor R3, and a resistor R4; one ends of the keys S1, S2, S3 and S4 are connected with the ground wire; the other end of the key S1 is connected with a pin 10 of the STMF103C8T6 singlechip, and the other end of the key S1 is connected with a +5V power supply through a resistor R1; the other end of the key S2 is connected with a pin 11 of the STMF103C8T6 singlechip, and the other end of the key S2 is connected with a +5V power supply through a resistor R2; the other end of the key S3 is connected with a pin 12 of the STMF103C8T6 singlechip, and the other end of the key S3 is connected with a +5V power supply through a resistor R3; the other end of the key S4 is connected with a pin 13 of the STMF103C8T6 singlechip, and the other end of the key S4 is connected with a +5V power supply through a resistor R4.

As a further improved technical scheme of the utility model, the TFT-LCD display circuit adopts a TFT-LCD color display screen, pin 1 of the TFT-LCD color display screen is connected with a +3.3V power supply, pin 2 of the TFT-LCD color display screen is connected with pin 31 of an STMF103C8T6 singlechip, pin 3 of the TFT-LCD color display screen is connected with pin 30 of an STMF103C8T6 singlechip, pin 4 of the TFT-LCD color display screen is connected with pin 29 of an STMF103C8T6 singlechip, pin 5 of the TFT-LCD color display screen is connected with pin 17 of an STMF103C8T6 singlechip, pin 6 of the TFT-LCD color display screen is connected with pin 16 of an STMF103C8T6 singlechip, pin 7 of the TFT-LCD color display screen is connected with pin 15 of an STMF103C8T6, pin 8 of the TFT-LCD color display screen is connected with pin 14 of an STMF103C8T6 singlechip, and a pin 9 of the TFT-LCD color display screen is connected with a ground wire.

The MAX038 signal generating circuit adopts MAX038 as a signal generating unit of the whole circuit. The X9511 digital potentiometer circuit adopts an X9511 digital potentiometer as a controlled object, and changes the potential of the access signal generating circuit by changing the position of a sliding end so as to control the duty ratio of the waveform of an output signal. The CD4051 digital switch circuit adopts a CD4051 digital switch as a controlled object, selects an input channel through software coding, and further changes an access capacitor to change the waveform frequency of an output signal. The key circuit realizes the setting of the output signal by pressing different keys, and can select different output waveforms. The minimum system circuit of the single chip microcomputer selects STM32F103C8T6 as a main controller to process the acquired data, and the minimum system of the single chip microcomputer further comprises a crystal oscillator system and a reset circuit. The TFT-LCD display circuit adopts a TFT liquid crystal screen for displaying, and can display the output waveform and frequency in real time. The power supply conversion circuit is divided into two parts, one part converts an input +12V power supply signal into +5V and-5V voltage signals and supplies the +5V voltage signals to the MAX038 signal generation circuit, and the other part converts the input +5V power supply signal into +3.3V voltage signals and supplies the +3.3V voltage signals to other devices for power supply input. The signal conditioning circuit mainly processes output signals, and comprises a lifting circuit, and an inverting proportional operational circuit is formed by one LM358 operational amplifier. The reverse phase input end of the reverse phase proportion operation circuit is connected with the lifting voltage through the mechanical potentiometer in a voltage dividing mode, the lifting voltage can be changed by adjusting the position of the sliding contact, the waveform lifting of a voltage signal is achieved, and the input requirement of the single chip microcomputer ADC is met.

The utility model has the advantages that:

the utility model discloses use STM32F103 singlechip as main control unit, through the function signal generator of MAX038 high accuracy, can accurately export different waveform signal to select the waveform signal of output through singlechip control peripheral circuit, output waveform signal is collected by the singlechip after signal conditioning, finally can accurately demonstrate output waveform and waveform frequency etc. on the display screen. The utility model discloses use when not only being limited to the teaching experiment, also be applicable to the testing personnel and detect equipment parameter. Experiments show that the test result of the circuit accords with the actual test result, the design is feasible and effective, the instruction can be quickly and accurately executed, the anti-interference performance is good, and the circuit has wide application value. The circuit is simple and reliable, the power consumption is low, the test result is stable, and the cost is low. The waveform type selection is simple and convenient, and the flexibility is high. The output waveform signal is accurate and stable, and has good anti-interference performance.

Drawings

Fig. 1 is a schematic block diagram of the circuit of the present invention.

Fig. 2 is a schematic diagram of the circuit principle of the present invention.

Detailed Description

The following further description of embodiments of the invention is made with reference to the accompanying drawings:

as shown in fig. 1, this embodiment provides a signal generator circuit based on an STM32 single chip microcomputer, which includes a MAX038 signal generator circuit, an X9511 digital potentiometer circuit, a CD4051 digital switch circuit, a key circuit, a minimum system circuit of the single chip microcomputer, a TFT-LCD display circuit, a power supply conversion circuit, and a signal conditioning circuit.

The signal generator circuit based on the STM32 single chip microcomputer is mainly designed through MAX038, the type, the frequency and the duty ratio of an output signal waveform are selected through keys, the circuit is driven by the STM32F103 single chip microcomputer, the single chip microcomputer measures the output of the signal generation circuit through an internal ADC and converts the result, the result is displayed on a TFT-LCD screen, and the circuit is as shown in FIG. 1 and FIG. 2. In the embodiment, a MAX038 is used as a main test unit, and an X9511 digital potentiometer circuit, a CD4051 digital switch circuit, a key circuit, a single chip microcomputer minimum system circuit, a TFT-LCD display circuit, a power supply conversion circuit and a signal conditioning circuit are designed. After the system is initialized, a user can mainly select the type of the waveform of the output signal through a key, and the single chip microcomputer can control the peripheral circuit to output sine waves, square waves and triangular waves according to a user instruction. By switching the selection parameters through keys, the frequency and the duty ratio of the output signal waveform can be selected. After receiving a user instruction, the single chip microcomputer can control the duty ratio of the waveform of the output signal by controlling the X9511 digital potentiometer and control the waveform of the output frequency signal by controlling the CD4051 digital switch to select the access circuit capacitor. The output signal can not be directly collected by the single chip microcomputer, and the signal conditioning circuit is designed to enable the waveform of the output signal to be collected, processed and drawn on the TFT-LCD display screen, and set parameters are displayed. Due to the special requirements of the power supply of the single chip microcomputer and the power supply of the MAX038 chip, the WRA1205CKS-1W and the LM1117T-3.3V voltage conversion modules are required to respectively supply power to the signal generation chip and the single chip microcomputer.

The specific connection relationship of the above circuits is as follows:

in this embodiment, as shown in fig. 2, the power conversion circuit includes a WRA1205CKS-1W power module and an LM1117-3.3V regulator. A pin 1 of the WRA1205CKS-1W power supply module is connected with a ground wire, a pin 2 of the LM1117-3.3V voltage stabilizer is connected with a +12V power supply, a pin 6 of the LM1117-3.3V voltage stabilizer is connected with one end of a capacitor C23, a pin 8 of the LM1117-3.3V voltage stabilizer is connected with one end of a capacitor C22, and a pin 7 of the LM1117-3.3V voltage stabilizer is simultaneously connected with the other ends of the capacitor C23 and the capacitor C22; and a pin 8 of the WRA1205CKS-1W power supply module is used for outputting a-5V power supply, and a pin 6 is used for outputting a +5V power supply. Pin 1 of LM1117-3.3V stabiliser connects the ground wire, LM1117-3.3V stabiliser's pin 2 connects +5V power, and pin 2 passes through electric capacity C24 and connects the ground wire, connects the ground wire through electric capacity C25, LM1117-3.3V stabiliser's pin 3 passes through electric capacity C26 and connects the ground wire, connects the ground wire through electric capacity C27, LM1117-3.3V stabiliser's pin 3 is used for exporting +3.3V power.

As shown in FIG. 2, the power conversion circuit mainly employs a WRA1205CKS-1W power module and an LM1117-3.3V voltage regulator. The WRA1205CKS-1W power supply module has the characteristics of wide input voltage range and alternating current and direct current, and is widely applied to various alternating current and direct current power supply systems and peripheral circuit occasions requiring safe isolation and simple multi-path output. The capacitors C22 and C23 are output filter capacitors, and each channel of the output is ensured to run safely and reliably. The LM1117-3.3V voltage stabilizer is a forward low-voltage drop stabilizer with 3.3V output voltage, wherein, capacitors C24 and C25 are input capacitors which rectify the voltage and prevent the voltage from inverting after power failure, therefore, the capacity of the input capacitor should be larger than that of the output capacitor. Capacitors C26 and C27 are output filter capacitors and are used to suppress self-oscillation, and if these capacitors are not connected, the output of the linear regulator will be an oscillating waveform. Trimming on the chip adjusts the reference voltage to within 1.5% of the error and the current limit is adjusted to minimize stress caused by overloading the regulator and power circuit.

In this embodiment, as shown in fig. 2, the minimum system circuit of the single chip microcomputer adopts an STMF103C8T6 single chip microcomputer, a pin 9, a pin 24, a pin 36 and a pin 48 of the STM32F103C8T6 single chip microcomputer are all connected to a +3.3V power supply, the +3.3V power supply is connected to a ground through a capacitor C2, a pin 47, a pin 35, a pin 23 and a pin 8 of the STM32F103C8T6 single chip microcomputer are all connected to the ground, a pin 44 of the STM32F103C8T6 single chip microcomputer is connected to the ground through a resistor R11, a pin 20 of the STM32F103C8T6 single chip microcomputer is connected to the ground through a resistor R12, a pin 3 of the STM32F103C8T6 single chip microcomputer is simultaneously connected to one end of a capacitor C6 and one end of a crystal oscillator Y1, a pin 4 of the STM32F103C 6C 8T6 is simultaneously connected to one end of the capacitor C7 and the other end of the crystal oscillator Y1, the other end of the capacitor C6 and the capacitor C468C 465C 466, and one end of the single chip microcomputer are simultaneously connected to one, The other end of the resistor R14 is connected with the other end of the crystal oscillator Y2, the other ends of the capacitor C11 and the capacitor C16 are both connected with the ground wire, a pin 7 of the STM32F103C8T6 single-chip microcomputer is connected with one end of a resistor R15, one end of a key S5 and one end of a capacitor C21, the other end of the resistor R15 is connected with a +3.3V power supply, the other ends of the key S5 and the capacitor C21 are both connected with the ground wire, and a pin 1 of the STM32F103C8T6 single-chip microcomputer is connected with the.

The minimum system circuit of the single chip microcomputer shown in fig. 2 is composed of a power supply circuit, a reset circuit and a crystal oscillator circuit. In the MCU control module, STM32F103C8T6 is used as the CPU of the whole system to complete the coordination work among the modules of calculation, processing, transmission and control of data. The RESET function is realized through the resistor R15, the capacitor C21 and the key S5, so that an RC charge-discharge loop is formed to ensure that the high level of the RESET pin has enough time to RESET when the single chip microcomputer is powered on, and then the high level returns to the low level to enter a normal working state. A starting circuit of the single chip microcomputer is formed by resistors R11 and R12, and a clock circuit is provided for the single chip microcomputer through a high-speed crystal oscillator Y1, a low-speed crystal oscillator Y2, filter capacitors C6, C7, C11 and C16. The power supply circuit adopts direct current 3.3V for power supply, and provides a stable working power supply for the singlechip through capacitors C24, C25, C26 and C27.

In this embodiment, as shown in fig. 2, the MAX038 signal generating circuit employs a MAX038 function generator, pin 3 of the MAX038 function generator is connected to pin 18 of the STMF103C8T6 single chip microcomputer, pin 4 of the MAX038 function generator is connected to pin 38 of the STMF103C8T6 single chip microcomputer, pin 7 of the MAX038 function generator is connected to the X9511 digital potentiometer circuit, pin 19 of the MAX038 function generator is connected to the signal conditioning circuit, a resistor R13 is connected between pin 1 and pin 10 of the MAX038 function generator, pin 5 of the MAX038 function generator is connected to the CD4051 digital switch circuit, pin 20 of the MAX038 function generator is connected to the-5V power supply and one end of a capacitor C3, pin 17 of the MAX038 function generator is connected to one end of a +5V power supply and one end of a capacitor C5, the other ends of the capacitor C3 and the capacitor C5 are connected to pin 18 of the MAX038 function generator, and the pin 15, the pin 13, the pin 12, the pin 11, the pin 9, the pin 6 and the pin 2 of the MAX038 function generator are all connected with a ground wire.

As shown in the MAX038 signal generating circuit of fig. 2, MAX038 is a high-frequency, high-precision function generator capable of generating precise, high-frequency triangular, sinusoidal, and square waves with a minimum of external components. The output frequency can be controlled in the frequency range of 0.1Hz to 20MHz by an internal 2.5V bandgap reference voltage and external resistors and capacitors. By using a control signal of 2.3V, the duty cycle can be varied over a wide range, facilitating pulse width modulation and generation of a sawtooth waveform.

In this embodiment, as shown in fig. 2, the X9511 digital potentiometer is used in the X9511 digital potentiometer circuit, pin 1 of the X9511 digital potentiometer is connected to pin 28 of the STMF103C8T6 single chip microcomputer, pin 2 of the X9511 digital potentiometer is connected to pin 27 of the STMF103C8T6 single chip microcomputer, pin 3 of the X9511 digital potentiometer is connected to a +5V power supply, pin 4 of the X9511 digital potentiometer is connected to a ground line, pin 5 of the X9511 digital potentiometer is connected to pin 7 of the MAX038 function generator, pin 6 of the X9511 digital potentiometer is connected to a-5V power supply, pin 7 of the X9511 digital potentiometer is connected to a ground line, pin 8 of the X9511 digital potentiometer is connected to a +5V power supply through a diode D1, and pin 8 is connected to a ground line through a capacitor C1.

As shown in the X9511 digital potentiometer circuit shown in fig. 2, a Schottky diode D1 supplies power to the X9511 digital potentiometer, PU and PD positions of the X9511 digital potentiometer are connected to an IO port of a single chip microcomputer, and the single chip microcomputer can control the position of a sliding end to select output voltage. The output voltage signal is connected to the DADJ pin of MAX038 to realize the regulation of different duty ratios of the waveform.

In this embodiment, as shown in fig. 2, the CD4051 digital switch circuit adopts a CD4051 digital switch, pin 16 of the CD4051 digital switch is connected to a +5V power supply, pin 9 of the CD4051 digital switch is connected to pin 34 of the STMF103C8T6 single-chip microcomputer, pin 10 of the CD4051 digital switch is connected to pin 33 of the STMF103C8T6 single-chip microcomputer, pin 11 of the CD4051 digital switch is connected to pin 32 of the STMF103C8T6 single-chip microcomputer, pin 6, pin 7, and pin 8 of the CD4051 digital switch are all connected to a ground, pin 4 of the CD4051 digital switch is connected to the ground through a capacitor C19 and a capacitor C20 in sequence, pin 2 of the CD4051 digital switch is connected to the ground through a capacitor C18, pin 5 of the CD4051 digital switch is connected to the ground through a capacitor C17, pin 1 of the CD4051 digital switch is connected to the ground through a capacitor C14 and a capacitor C15 in sequence, pin 3612 of the CD4051 digital switch is connected to the ground through a capacitor C, the pin 15 of the CD4051 digital switch is connected with the ground wire through a capacitor C12, the pin 14 of the CD4051 digital switch is connected with the ground wire through a capacitor C10, the pin 13 of the CD4051 digital switch is connected with the ground wire through a capacitor C8 and a capacitor C9 in sequence, and the pin 3 of the CD4051 digital switch is connected with the pin 5 of the MAX038 function generator.

For the CD4051 digital switch circuit shown in fig. 2, +5V is used for power supply, the C, B, A pin of the CD4051 digital switch is connected to the IO port of the single chip, different encoding values can be output through the IO port of the single chip, different input capacitance values are further selected, and then the COM pin of the CD4051 digital switch is input to the COSC pin of MAX038, so that the adjustment of the waveform frequency can be realized.

In this embodiment, as shown in fig. 2, the signal conditioning circuit employs an LM358 operational amplifier, a pin 1 of the LM358 operational amplifier is connected to one end of a resistor R7 and a slide rheostat RP1 at the same time, the other end of the resistor R7 is connected to a pin 19 of an STMF103C8T6 single chip microcomputer, the other end of the resistor R7 is connected to a ground through a resistor R10, a pin 4 of the LM358 operational amplifier is connected to a-5V power supply, a pin 8 of the LM358 operational amplifier is connected to a +5V power supply, a pin 2 of the LM358 operational amplifier is connected to one end of a resistor R5 and the other end of a slide rheostat RP1 and a slide end at the same time, the other end of a resistor R5 is connected to a ground, a pin 3 of the LM358 operational amplifier is connected to one end of a resistor R9 and one end of a resistor R6 at the same time, the other end of a resistor R9 is connected to a slide rheostat RP2, one end, the other end of the resistor R6 is connected with one end of a resistor R8, one end of a capacitor C4 and a pin 19 of the MAX038 function generator, and the other end of the resistor R8 and the other end of the capacitor C4 are both connected with a ground wire.

The conditioning circuit shown in fig. 2 includes a voltage signal boosting circuit, and an inverting proportional operational circuit is formed by a piece of LM358 operational amplifier. The reverse phase input end of the reverse phase proportion operation circuit is connected with the lifting voltage through the mechanical potentiometer in a voltage dividing mode, the lifting voltage can be changed by adjusting the position of the sliding contact, the waveform lifting of a voltage signal is achieved, and the input requirement of the single chip microcomputer ADC is met.

In this embodiment, as shown in fig. 2, the key circuit includes a key S1, a key S2, a key S3, a key S4, a resistor R1, a resistor R2, a resistor R3, and a resistor R4; one ends of the keys S1, S2, S3 and S4 are connected with the ground wire; the other end of the key S1 is connected with a pin 10 of the STMF103C8T6 singlechip, and the other end of the key S1 is connected with a +5V power supply through a resistor R1; the other end of the key S2 is connected with a pin 11 of the STMF103C8T6 singlechip, and the other end of the key S2 is connected with a +5V power supply through a resistor R2; the other end of the key S3 is connected with a pin 12 of the STMF103C8T6 singlechip, and the other end of the key S3 is connected with a +5V power supply through a resistor R3; the other end of the key S4 is connected with a pin 13 of the STMF103C8T6 singlechip, and the other end of the key S4 is connected with a +5V power supply through a resistor R4.

The key part circuit shown in fig. 2 adopts 4 independent keyboards, and the type and frequency of the output waveform of the function signal generator and the duty ratio control can be realized by pressing different keys. The independent keyboard is simple to program, the number of key operations used by the device is small, the wiring and programming modes of the independent keyboard are simple, and the independent keyboard is selected compared with a matrix keyboard connection method which is complex in programming and saves I/O ports. The single chip microcomputer detects whether the I/O port corresponding to the key is at a low level or not.

In this embodiment, as shown in fig. 2, the TFT-LCD display circuit adopts a TFT-LCD color display screen, pin 1 of the TFT-LCD color display screen is connected with a +3.3V power supply, pin 2 of the TFT-LCD color display screen is connected with pin 31 of the STMF103C8T6 singlechip, pin 3 of the TFT-LCD color display screen is connected with pin 30 of the STMF103C8T6 singlechip, pin 4 of the TFT-LCD color display screen is connected with pin 29 of the STMF103C8T6 singlechip, pin 5 of the TFT-LCD color display screen is connected with pin 17 of the STMF103C8T6 singlechip, pin 6 of the TFT-LCD color display screen is connected with pin 16 of the STMF103C8T6 singlechip, pin 7 of the TFT-LCD color display screen is connected with pin 15 of the STMF103C8T6 singlechip, and a pin 8 of the TFT-LCD color display screen is connected with a pin 14 of the STMF103C8T6 singlechip, and a pin 9 of the TFT-LCD color display screen is connected with a ground wire.

The TFT-LCD display circuit shown in fig. 2 employs a TFT-LCD color display panel, which is one of active matrix liquid crystal displays. The display device can control each pixel point on the screen, so that the response time can be greatly prolonged, a driving signal and various synchronous signals can be generated as long as a power supply is provided, and the display of an output result can be effectively met. The TFT-LCD color display screen has the characteristics of good brightness, high contrast, strong layering and bright color. The output waveform signal can be clearly drawn, and the frequency and the duty ratio of the output waveform can be displayed.

The embodiment is mainly characterized in that different signal waveforms sent by a high-precision function signal generator can be controlled by a key and output waveforms are displayed by a TFT-LCD display screen. This embodiment uses STM32F103 singlechip as main control unit, sends to the singlechip after handling the voltage to signal generator output, shows the setting of wave form and parameter on TFT-LCD display screen afterwards. The embodiment can set the output waveform for the function signal generator by pressing keys, draw the output waveform and display various parameters of the waveform. The embodiment is not limited to ordinary teaching experiments, and is also suitable for detecting equipment parameters by testers. Experiments show that the test result of the circuit accords with the actual test result, the design is feasible and effective, the instruction can be quickly and accurately executed, the anti-interference performance is good, and the circuit has wide application value.

Tests show that the circuit can quickly and accurately generate a specified waveform signal, and has good anti-interference performance and convenient control. The signal generator can be popularized to scenes needing experiment teaching and equipment testing, is reliable in work and has high practical application value. Through testing, the whole circuit has stable test condition, high reliability and high efficiency in design, accurate output waveform signals, good anti-interference performance, convenient control, low power consumption and wide application applicability.

While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a signal generator circuit based on STM32 singlechip which characterized in that: the system comprises an MAX038 signal generating circuit, an X9511 digital potentiometer circuit, a CD4051 digital switch circuit, a key circuit, a singlechip minimum system circuit, a TFT-LCD display circuit, a power supply conversion circuit and a signal conditioning circuit;

2. The STM32 singlechip-based signal generator circuit of claim 1, wherein: the power supply conversion circuit comprises a WRA1205CKS-1W power supply module and an LM1117-3.3V voltage stabilizer;

3. An STM32 single chip microcomputer-based signal generator circuit as claimed in claim 2, wherein: the minimum system circuit of the single-chip microcomputer adopts an STMF103C8T6 single-chip microcomputer, a pin 9, a pin 24, a pin 36 and a pin 48 of the STM32F103C8T6 single-chip microcomputer are connected with a +3.3V power supply, the +3.3V power supply is connected with a ground wire through a capacitor C2, a pin 47, a pin 35, a pin 23 and a pin 8 of the STM32F103C8T6 single-chip microcomputer are connected with the ground wire, a pin 44 of the STM32F103C8T6 single-chip microcomputer is connected with the ground wire through a resistor R11, a pin 20 of the STM32F103C8T6 single-chip microcomputer is connected with the ground wire through a resistor R12, a pin 3 of the STM32F103C8T6 single-chip microcomputer is simultaneously connected with one end of a capacitor C8 and one end of a crystal oscillator Y1, a pin 4 of the STM32F103C8T6 is simultaneously connected with one end of the capacitor C7 and the other end of the crystal oscillator Y1, the capacitor C6 and the other end of the capacitor C7 are simultaneously connected with the ground wire, a pin 465C 465 pin of the single-chip microcomputer, and one end of, The other end of the resistor R14 is connected with the other end of the crystal oscillator Y2, the other ends of the capacitor C11 and the capacitor C16 are both connected with the ground wire, a pin 7 of the STM32F103C8T6 single-chip microcomputer is connected with one end of a resistor R15, one end of a key S5 and one end of a capacitor C21, the other end of the resistor R15 is connected with a +3.3V power supply, the other ends of the key S5 and the capacitor C21 are both connected with the ground wire, and a pin 1 of the STM32F103C8T6 single-chip microcomputer is connected with the.

4. An STM32 single chip microcomputer-based signal generator circuit as claimed in claim 3, wherein: MAX038 signal generation circuit adopts MAX038 function generator, MAX038 function generator's pin 3 is connected with STMF103C8T6 singlechip's pin 18, MAX038 function generator's pin 4 is connected with STMF103C8T6 singlechip's pin 38, MAX038 function generator's pin 7 and X9511 digital potentiometer circuit connection, MAX038 function generator's pin 19 is connected with signal conditioning circuit, be connected with resistance R13 between MAX038 function generator's pin 1 and pin 10, MAX038 function generator's pin 5 and CD4051 digital switch circuit connection, MAX038 function generator's pin 20 is connected with-5V power supply and electric capacity C3 one end simultaneously, MAX038 function generator's pin 17 is connected with +5V power supply and electric capacity C5 one end simultaneously, electric capacity C3 and electric capacity C5 other end all with MAX 038's pin 18 is connected, MAX038 function generator's pin 15 is connected, Pin 13, pin 12, pin 11, pin 9, pin 6, and pin 2 are all connected to ground.

5. An STM32 single chip microcomputer-based signal generator circuit as claimed in claim 4, wherein: the X9511 digital potentiometer circuit adopts an X9511 digital potentiometer, a pin 1 of the X9511 digital potentiometer is connected with a pin 28 of an STMF103C8T6 singlechip, a pin 2 of the X9511 digital potentiometer is connected with a pin 27 of the STMF103C8T6 singlechip, a pin 3 of the X9511 digital potentiometer is connected with a +5V power supply, a pin 4 of the X9511 digital potentiometer is connected with a ground wire, a pin 5 of the X9511 digital potentiometer is connected with a pin 7 of a MAX038 function generator, a pin 6 of the X9511 digital potentiometer is connected with a-5V power supply, a pin 7 of the X9511 digital potentiometer is connected with a ground wire, a pin 8 of the X9511 digital potentiometer is connected with the +5V power supply through a diode D1, and the pin 8 is connected with the ground wire through a capacitor C1.

6. An STM32 single chip microcomputer-based signal generator circuit as claimed in claim 4, wherein: the CD4051 digital switch circuit adopts a CD4051 digital switch, a pin 16 of the CD4051 digital switch is connected with a +5V power supply, a pin 9 of the CD4051 digital switch is connected with a pin 34 of an STMF103C8T6 singlechip, a pin 10 of the CD4051 digital switch is connected with a pin 33 of the STMF103C8T6 singlechip, a pin 11 of the CD4051 digital switch is connected with a pin 32 of the STMF103C8T6 singlechip, a pin 6, a pin 7 and a pin 8 of the CD4051 digital switch are all connected with a ground wire, a pin 4 of the CD4051 digital switch is connected with the ground wire through a capacitor C19 and a capacitor C20 in sequence, a pin 2 of the CD4051 digital switch is connected with the ground wire through a capacitor C18, a pin 5 of the CD4051 digital switch is connected with the ground wire through a capacitor C17, a pin 1 of the CD4051 digital switch is connected with the ground wire through a capacitor C14 and a capacitor C15 in sequence, a pin 12 of the CD4051 digital switch is connected with the ground wire through a capacitor C4023, the pin 14 of the CD4051 digital switch is connected with the ground wire through a capacitor C10, the pin 13 of the CD4051 digital switch is connected with the ground wire through a capacitor C8 and a capacitor C9 in sequence, and the pin 3 of the CD4051 digital switch is connected with the pin 5 of the MAX038 function generator.

7. An STM32 single chip microcomputer-based signal generator circuit as claimed in claim 4, wherein: the signal conditioning circuit adopts an LM358 operational amplifier, a pin 1 of the LM358 operational amplifier is simultaneously connected with one end of a resistor R7 and one end of a slide rheostat RP1, the other end of the resistor R7 is connected with a pin 19 of an STMF103C8T6 singlechip, the other end of a resistor R7 is connected with a ground wire through a resistor R10, a pin 4 of the LM358 operational amplifier is connected with a-5V power supply, a pin 8 of the LM358 operational amplifier is connected with a +5V power supply, a pin 2 of the LM358 operational amplifier is simultaneously connected with one end of a resistor R5 and the other end of the slide rheostat RP1 and a sliding end, the other end of a resistor R5 is connected with the ground wire, a pin 3 of the LM358 operational amplifier is simultaneously connected with one end of a resistor R9 and one end of a resistor R6, the other end of a resistor R9 is connected with a sliding end of an RP2, one end of an RP2 is connected with, the other end of the resistor R6 is connected with one end of a resistor R8, one end of a capacitor C4 and a pin 19 of the MAX038 function generator, and the other end of the resistor R8 and the other end of the capacitor C4 are both connected with a ground wire.

8. The STM32 singlechip-based signal generator circuit of claim 1, wherein: the key circuit comprises a key S1, a key S2, a key S3, a key S4, a resistor R1, a resistor R2, a resistor R3 and a resistor R4; one ends of the keys S1, S2, S3 and S4 are connected with the ground wire; the other end of the key S1 is connected with a pin 10 of the STMF103C8T6 singlechip, and the other end of the key S1 is connected with a +5V power supply through a resistor R1; the other end of the key S2 is connected with a pin 11 of the STMF103C8T6 singlechip, and the other end of the key S2 is connected with a +5V power supply through a resistor R2; the other end of the key S3 is connected with a pin 12 of the STMF103C8T6 singlechip, and the other end of the key S3 is connected with a +5V power supply through a resistor R3; the other end of the key S4 is connected with a pin 13 of the STMF103C8T6 singlechip, and the other end of the key S4 is connected with a +5V power supply through a resistor R4.

9. The STM32 singlechip-based signal generator circuit of claim 1, wherein: the TFT-LCD display circuit adopts a TFT-LCD color display screen, pin 1 of the TFT-LCD color display screen is connected with a +3.3V power supply, pin 2 of the TFT-LCD color display screen is connected with pin 31 of the STMF103C8T6 singlechip, pin 3 of the TFT-LCD color display screen is connected with pin 30 of the STMF103C8T6 singlechip, pin 4 of the TFT-LCD color display screen is connected with pin 29 of the STMF103C8T6 singlechip, pin 5 of the TFT-LCD color display screen is connected with pin 17 of the STMF103C8T6 singlechip, pin 6 of the TFT-LCD color display screen is connected with pin 16 of the STMF103C8T6 singlechip, pin 7 of the TFT-LCD color display screen is connected with pin 15 of the STMF103C8T6 singlechip, and a pin 8 of the TFT-LCD color display screen is connected with a pin 14 of the STMF103C8T6 singlechip, and a pin 9 of the TFT-LCD color display screen is connected with a ground wire.