RU2550595C1 - Microcontroller device to measure capacitance and resistance and transfer of measurement result along radio channel - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: microcontroller device for measurement of capacitance and resistance and transfer of the measurement result along a radio channel comprises a microcontroller (MC) 1, a sample resistor 2 (Ro), a capacitance sensor 3 (Cx), for instance, of air moisture, a resistor 4 (measured resistance Rx), for instance, a thermistor, a capacitor of sample capacitance 5 (Co), a resistive divider, comprising resistors 6 and 7, an outlet 8 of binary code transfer. Resistors 2 and 4 by the first outlets are connected to a non-inverting inlet of an analogue comparator of an MC 1 and the first plates of the capacitance sensor 3 and the capacitor 5 of sample capacitance, the first outlets of resistors 6 and 7 of the voltage divider are connected to the inverting inlet of the analogue comparator of the MC 1, the second outlets of resistors 2 and 4 are connected, accordingly, to the first and second outlets of the MC 1, the second plates of the capacitance sensor 3 and the capacitor 5 of the sample capacitance are connected, accordingly, to the third and fourth outlets of the MC 1, the second outlets of resistors 6 and 7 of the voltage divider are connected accordingly to the fifth and sixth outlets of the MC 1, the outlet of measurement result transfer of the MC 1 is connected to the inlet of the reception of the binary code of a radio module 8, the discrete outlet of the radio module 8 is connected to the inlet of control of the power saving mode of the MC.

EFFECT: expansion of functional capabilities.

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Description

FIELD OF THE INVENTION

The invention relates to measuring equipment, in particular to devices for measuring capacitance and active resistance, and can be used in means for measuring and monitoring non-electric quantities by capacitive and resistive sensors and transmitting the measurement result over the air.

State of the art

A device for measuring non-electric quantities by capacitor sensors is known, containing the first and second generators, a microcontroller (MK) and a digital indicator, the capacitor sensor of the measured capacitance and the capacitor of the model capacitance are included in the timing circuits of the generators, the timing resistors are turned on according to known schemes, the outputs of the generators are connected to the counting inputs of the corresponding MK counters, one of the MK outputs is connected to the generation enable inputs of both generators, a digital indicator p dklyuchen to MK (see. US Pat. Russian Federation №2214610, cl. G01R 27/26).

The disadvantages of the known solution - limited functionality - the device does not allow the transmission of the measurement results of capacitance and resistance over the air.

A device is known for measuring the capacitance and dielectric loss of a capacitor sensor, comprising an MK, digital indicator, first and second generators, the timing circuits of which contain, respectively, a capacitor sensor, a capacitor of exemplary capacity and timing resistors included according to known schemes, controlled keys, outputs of the first and the second generators are connected to the MK inputs, the MK output is connected to the generation enable inputs of both generators, a digital indicator is connected to the output of the binary code MK (see Pat. RF №2258232, CL G01R 27/26).

The disadvantages of the known solution - limited functionality - the device does not allow the transmission of the measurement results of capacitance and resistance over the air.

The closest in technical essence to the claimed technical solution and adopted by the authors for the prototype is a microcontroller measuring transducer of capacitance and resistance to binary code containing a microcontroller, capacitive sensor, capacitor of exemplary capacitance, exemplary resistor, resistor of measured resistance, resistive voltage divider, binary code transmission output moreover, the resistors of exemplary and measured resistance by the first conclusions are connected to the first plates, respectively, the capacitance the first sensor and the capacitor of the standard capacitance, the first terminals of the resistors of the voltage divider are connected to the first input of the analog comparator of the microcontroller, and the second conclusions are connected respectively to the terminals of the power of the microcontroller, the first conclusions of the model and measured resistors are connected to the second input of the analog comparator of the microcontroller, the second conclusions of the model and measured resistors connected, respectively, to the first and second outputs of the microcontroller, the second capacitive sensor plates and the capacitor exemplary capacitance connected respectively to third and fourth outputs of the microcontroller (see. US Pat. RF №2391677, class G01R 27/26).

The disadvantages of the known solution - limited functionality - the device does not allow to transmit the results of measuring capacitance and resistance over the air

Disclosure of invention

The technical result that can be achieved using the present invention is to expand the functionality, namely, the measurement information is transmitted over the air.

The technical result is achieved by the fact that in the microcontroller device for measuring capacitance and resistance and transmitting the measurement result over the air, containing a microcontroller, a capacitive sensor, a capacitor of exemplary capacity, a model resistor and a resistor of the measured resistance, the first and second resistors of the voltage divider, the output of the binary code transmission, the resistors of the exemplary and measured resistance by the first terminals are connected to the first plates, respectively, of the capacitive sensor and the capacitor exemplary capacitance, the first conclusions of the voltage divider resistors are connected to the first input of the analog comparator of the microcontroller, the first conclusions of the reference and measured resistors are connected to the second input of the analog comparator of the microcontroller, the second conclusions of reference and measured resistors are connected, respectively, to the first and second outputs of the microcontroller, the second capacitor sensor plates and a capacitor of exemplary capacity are connected, respectively, to the third and fourth outputs of the MK, a radio module is introduced, and the second The conclusions of the first and second voltage divider resistors connected respectively to the fifth and sixth outputs of the microcontroller, the microcontroller binary code transmit output connected to an input receiving a binary radio, radio logic output connected to the control input of the microcontroller power saving mode.

Brief Description of the Drawings

Figure 1 shows the structural diagram of a microcontroller device for measuring capacitance and resistance and transmitting the measurement result over the air

The implementation of the invention

A microcontroller device for measuring capacitance and resistance and transmitting the measurement result over the air contains (Fig. 1) a microcontroller (MK) 1, a reference resistor 2 (Ro), a capacitive sensor 3 (Cx), for example, air humidity, resistor 4 (measured resistance Rx) , for example, thermal resistance, a capacitor of exemplary capacity 5 (Co), a resistive divider consisting of resistors 6 and 7, the output 8 of the binary code transmission. The resistors 2 and 4 are connected with the first outputs to the non-inverting input of the analog comparator MK 1 and the first plates of the capacitive sensor 3 and the capacitor 5 of the standard capacity, the first conclusions of the resistors 6 and 7 of the voltage divider are connected to the inverting input of the analog comparator MK 1, the second conclusions of the resistors 2 and 4 connected, respectively, to the first and second outputs of MK 1, the second plates of the capacitive sensor 3 and the capacitor 5 of the standard capacity are connected, respectively, to the third and fourth outputs of MK 1, the second terminals of the resistors 6 and 7 voltage divider connected, respectively, to the fifth and sixth outputs of MK 1, the output of the transmission of the measurement result MK 1 is connected to the input of the binary code of the radio module 8, the discrete output of the radio module 8 is connected to the control input of the energy-saving mode MK 1.

A microcontroller device for measuring capacitance and resistance and transmitting the measurement result over the air is as follows.

Thanks to the built-in timer, the radio module 8 goes from sleep mode to active and sends a signal (for example, logical 1) to the control input of energy saving mode MK1, which transfers MK 1 from sleep mode to active.

MK 1 outputs a high voltage level to the fifth output, a low voltage level to the sixth output, current flows through the circuit of the resistive divider 6, 7. A voltage equal to 0.63Uh is supplied from the resistive divider 6, 7 to the inverting input of the analog comparator MK 1, where Uh is the voltage between the fifth and sixth outputs of MK 1, i.e. high voltage level (logic 1). To measure the capacitance 3 MK switches off the circuit, consisting of a resistor 4 and a capacitor 5, by translating the second and fourth outputs to which this circuit is connected, in a high-resistance state. Then, the MK outputs a low voltage level (log. 0) to the third output and discharges the capacitance 3 through resistor 2, by outputting the log. 0 to the first exit. After a while, MK 1 outputs a high voltage level (log. 1) to the first output and starts the internal binary counter reset to zero. When the voltage at the capacitive sensor 3 reaches the level of 0.63Uh, a log will be generated at the output of the analog comparator. 1. On this signal MK 1 stops the binary counter and saves its contents, ie binary code N, which is proportional to the time constant τ = Ro · Cx. The binary code N is determined by the expression N = τ / T, where T is the period (cycle time) of the MK 1 clock, T = 1 / f is determined, where f is the frequency of the MK 1 clock. MK 1 determines the time constant from the expression τ = T · N, and then defines Cx = T · N / Ro, where Ro is known.

To measure the resistance of resistor 4, MK 1 performs the same algorithm as for measuring the capacitance 3. It determines Rx from the expression Rx = T · N / Co, where Co is known.

Binary codes of the conversion results MK 1 transmits through the output to the radio module 8. Radio module 8 transmits via radio channel information that is received by the radio receiver and transmitted, for example, to a computer, where it is processed and displayed on the monitor in appropriate units, for example, in degrees or percent relative humidity . This is the case when the temperature is controlled using a resistive sensor 4 and the humidity is controlled using a capacitive sensor 3 (Figure 1).

The invention in comparison with the prototype and other known solutions has the following advantages: expanded functionality, namely, the measurement information is transmitted over the air, which greatly simplifies the organization of systems for collecting information about controlled physical quantities.

Claims (1)

The microcontroller device for measuring capacitance and resistance and transmitting the measurement result over the air contains a microcontroller, a capacitive sensor, a reference capacitor, a reference resistor and a measured resistance resistor, first and second voltage divider resistors, a binary code transmission output, reference and measured resistance resistors with the first leads connected to the first plates, respectively, of the capacitive sensor and the capacitor of the model capacity, and divide the first conclusions of the resistors I voltage is connected to the first input of the analog comparator of the microcontroller, the first outputs of the model and measured resistors are connected to the second input of the analog comparator of the micro, controller is connected to the first and second outputs of the microcontroller, the second plates of the capacitive sensor and the capacitor of the standard capacity , respectively, to the third and fourth outputs of MK, characterized in that a radio module is inserted into it, and the second conclusions of the first and a second voltage divider resistors connected respectively to the fifth and sixth outputs of the microcontroller, the microcontroller binary code transmit output connected to an input receiving a binary radio, radio logic output connected to the control input of the microcontroller power saving mode.