Design Of Synchronous Acquisition Module For Multi-channel Photoelectric Signals

Photoelectric detection technology has a very wide range of application scenarios due to its advantages of rapid response,strong anti-interference ability,and suitability for long-distance telemetry.It is very necessary to research and develop photoelectric conversion circuits which meet different needs of replacing the more expensive imported photoelectric amplifier products.A multi-channel photoelectric signal synchronous acquisition circuit is designed and implemented in this paper,which has the characteristics of small size,fast real-time transmission rate,and high-cost performance.This paper proposes a framework using dual high-performance MCUs to achieve high-efficiency transmission of synchronous acquisition data.STM32G474VET6 is responsible for the synchronous acquisition of signals,and the high-speed USB2.0 interface of STM32H743IIT6 is responsible for the real-time transmission of acquired data.The two MCUs use 8-bit QSPI to achieve internal Acquisition data transmission.This structure can take advantage of the resources and performance of the two MCUs to achieve a transmission rate of 500 k SPS of four-channel optoelectronic signals,and a data storage rate of up to 2Mbps,which can meet the real-time acquisition application requirements of medium and low frequency optoelectronic signals.Synchronous signal acquisition usually requires the application of analog chips such as ADC,DAC,and comparator.This article uses STM32G474VET6,which is rich in analog resources,to integrate and implement,rationally configure its hardware resources,simplify circuit design,reduce hardware costs and improve program runtime.Three photoelectric signal conversion and conditioning circuits,single photocell,dual photocell frequency band extension and dual photocell differential are designed to realize the low cost and low power consumption of signal program-controlled gain setting to meet the needs of different application scenarios.The module is powered by a 5V DC power supply and four independent analog channels are applied to the module to transform output photoelectric signals and collect data.The adjustable range of the programmable gain of the trans-impedance amplifier is 0-70 d B,the step value is 10 d B,and the accuracy is 0.5d B;the output amplitude of the photoelectric conversion signal can reach 8Vpp,and the output trigger logic signal can be provided.The vertical resolution of data acquisition is12 bit,the sampling rate is up to 4Mbps,and it supports LAN communication and USB2.0 communication.This paper also designs a virtual instrument soft panel for four-channel photoelectric acquisition signals,verifies the circuit's functional indicators,and conducts experiments in the application scenario of vibrating fiber optic sensors.