Dielectric Usb-Moisture Meter for Seeds of Agricultural Crops

Vostrukhin, Aleksandr; Vakhtina, Elena; Mastepanenko, M. A.; Gabrielyan, Shaliko

doi:10.15544/rd.2017.034

Cited by 3 publications

(3 citation statements)

References 2 publications

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“…The results of experimental studies are shown in Tables 2 and 3. The values of Vsminand Vsmaxare determined by the formulas (8): (8) where TOPthe PWM3 resolution.…”

Section: Resultsmentioning

confidence: 99%

Investigating metering converter of capacitance using arduino platform

Vostrukhin

Vakhtina

2021

20th International Scientific Conference Engineering for Rural Development Proceedings

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The task of improving electronic devices for measuring the moisture content of agricultural seeds is always relevant. Knowledge of the best ways, methods and technical solutions in a particular field of activity is the basis for creating innovative devices. However, manufacturers do not disclose the hardware and software of their devices. This circumstance does not allow performing a comparative analysis and choosing the best solution, which slows down the technical progress and engineering education to a certain extent. This paper discusses the hardware and the operation algorithm for the measuring converter of capacitance (MCC), which is designed for constructing a dielcometric USB-moisture meter for seeds of agricultural crops, as well as the study results of its main characteristics. Arduino hardware and software (IDE) were used. A diagram of an experimental MCC sample, a model of a measuring circuit in the Multisim program and recommendations on the selection of elements for reference and measuring RC-circuits are presented. Studies have shown that MCC can be used for building dielcometric USB-moisture meters of seeds based on microcontrollers containing: an analog comparator, a twochannel 8-bit pulse width a modulator (PWM), a 10-bit PWM, and a USB interface. The transients used in MCC are fundamental, so the research results can be used in engineering education to study embedded computing systems. Transient processes in RC-circuits can be simulated in the Multisim program, as well as investigated using the Arduino platform, which allows to observe the results of the conversions on a computer monitor.

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“…The results of experimental studies are shown in Tables 2 and 3. The values of Vsminand Vsmaxare determined by the formulas (8): (8) where TOPthe PWM3 resolution.…”

Section: Resultsmentioning

confidence: 99%

Investigating metering converter of capacitance using arduino platform

Vostrukhin

Vakhtina

2021

20th International Scientific Conference Engineering for Rural Development Proceedings

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“…All microcontrollers contain, as a rule, at least two hardware binary counters of rectangular pulses. This allows organizing a fixed time interval (a gate time) on one counter, and on the other -to count the pulses received at its input during this time interval.The NE555 mathematical model is included in the popular at engineering faculties Multisim http://www.ni.com/multisim simulation environment for designing of electronic devices [1].…”

Section: Methodsmentioning

confidence: 99%

“…Microcontroller metering converter of capacitance (MMCC) was considered in [1]. The MMCCbased USB-moisture meter for seeds of agricultural crops was developed.The MMСC output signal is the frequency that depends on the capacity of the sensor in the cavity of which seeds are located.…”

Section: Introductionmentioning

confidence: 99%

Microcontroller metering converter of capacitance with voltage-controlled RC-generator

Vostrukhin

Vakhtina

Bondar

et al. 2018

Engineering for Rural Development

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Abstract. In agriculture, the moisture content of seeds, air and other materials is measured using capacitive sensors. The voltage (metering voltage, MV) that varies with a certain frequency is supplied to a capacitive sensor.The MV frequency can be either fixed or variable, depending on the measured capacitance changing. In the last case, additional errors occur during the measurement.For example, for Honeywell's HCH-1000 air humidity sensors, changing the MV frequency from 50 to 100 kHz leads to a humidity measurement error within 10 %. The main parameters of these sensors are given for the frequency of 20 kHz in the datasheet. It is known that the seed permittivity depends on the MV frequency of the capacitive sensor, in the cavity of which these seeds are located. Therefore, the task is to control the MV frequency.Microcontroller-controlled process of capacitance-to-binary code conversion is considered in the paper. Capacitance-to-frequency conversion is carried out using the NE555 chip operating in the auto-generator mode. Arduino's microcontroller measures the frequency at NE555 output, then its deviation from the value set is determined and an impact in the form of voltage is formed in order to eliminate this deviation. The result of the conversion is a binary code equivalent to the effect generated to eliminate the deviation. Thus, the MV frequency is maintained at a predetermined level.Experimental studies were carried out in a capacitancechange range from 200 to 400 pF. This range was selected because, when the air humidity varies from 0 to 100 %, the range of the HCH-1000 sensors capacitance changes from 280 to 380 pF. Microcontrollers allow us to solve the tasks of converting physical quantities into binary code quite simply and effectively. Binary code allows performing any arithmetic operations, which in turn increases the measurements accuracy. It does not require bulky hardware. All devices necessary for organizing the conversion process can be placed on a single semiconductor crystal in the future.Keywords: binary code, duty ratio, frequency, NE555, pulse-width modulator. IntroductionMicrocontroller metering converter of capacitance (MMCC) was considered in [1]. The MMCCbased USB-moisture meter for seeds of agricultural crops was developed.The MMСC output signal is the frequency that depends on the capacity of the sensor in the cavity of which seeds are located. The sensor capacity depends mainly on the seed moisture content. The MMCC output frequency is equal to the frequency of the electric field (EF) difference between the sensor's plates.It is known that the dielectric permittivity of seeds depends on the frequency of EF change.To increase the accuracy of measurements, it is necessary to stabilize this frequency or take its change into account.MMCC, which allows by program automatically control the EF frequency of the capacitive sensor that is discussed in the article.This solution allows pieces of metering at several frequencies, which can improve the accuracy of measurements.Studies of moi...

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