Development On The Second Generation Of HY114Digital Sound Level Meter Based On STM32

With the development of the society, science and technology, and the update ofthe sound evaluation quantity, an increasing percentage of the society’s fields areneeded to measure and surveil sound. The influences of the noise made by the fieldssuch as road traffic, construction sites are needed to be judged with an accurate number.So the demand for the measuring function and the accuracy of the sound level meter isincreasing. The technological improvement for HY114Sound Level Meter isimperative for its functions can’t really meet the needs of the development.A second generation of HY114based on the HY114Digital Sound Level Meterwas designed in this paper which was made by Hengyang Hengyi Instrument&Electric Equipment Ltd. and was combined with the function requirements of HY118Integral Statistics Sound Level Meter. The software and hardware’s designing schemesof the second generation of HY114were expounded detailedly in this paper, the mainhardware circuit and the design and realization of the main functions’ codes wereintroduced mainly.1) ARM embedded system STM32F103RDT6was chosen to replaceSTC12LE5608AD which is used in the first generation of HY114. The hardware’selectrical schematic diagram and the PCB were redesigned according to the STM32’spins features.2) The codes were re-written, Checking Table is used to slove the problem ofoccupying a large amount of RAM to store the sounds data, the integral statistics andcalculating functions for the equivalent continuous sound level were added, such as theMaximum and Minimum, Sound Exposure, Sound Exposure Level, Equivalent SoundLevel, Noise Dose, Cumulative Percentage of Sound Level, Standard Deviation andIntegral Time.3) The prototype’s calculating function and the accuracy of the results were tested by the field trail and the electrical signal test. Then proposed solutions and solved theproblems according to the founded problems, and tested the prototype’s calculatingfunction and the accuracy of the results again.The results showed that the measure, statistical analysis and calculating functionsof the second generation can be realized basically, at the same time, the accuracyproblem was founded in the test, and it needs to be solved in the future work. On theother hand, the powers of STM32can be fully used to update the product based on thesecond generation of HY114, digitizing the artificial circuits is the main direction ofthe designing and the requirement of the times and technological development.