Digital weighing sensor

Abstract

The utility model relates to a digital weighing sensor, which comprises a signal processing circuit and a digital communication circuit, a UART differential access port module of the signal processing circuit is connected with the input end of an ADC analog-to-digital conversion module through a PGA amplifier, and the output end of the ADC analog-to-digital conversion module is connected with the digital communication circuit through a processor. The Timer timer module and the WDT watchdog module are connected to the processor, and the control end of the processor is connected with the differential access port module, the PGA amplifier and the ADC analog-to-digital conversion module. The digital weighing sensor amplifies and compensates a sensor source signal collected at the front end before digital-to-analog conversion on the premise of outputting a digital signal with higher precision, interference and errors are not introduced after digital processing, and the precision and the rate of the output signal can be adjusted and coordinated according to needs.

Description

Technical Field

[0001] The utility model relates to the field of digital weighing sensors, in particular to a digital weighing sensor. Background Art

[0002] In a narrow sense, a sensor is a component that converts the change of a sensed physical quantity into a change of an electrical signal. The change of the electrical signal converted by the sensor is generally weak, and the signal characteristics are not suitable for transmission in the line. On this basis, the traditional analog transmitter converts the sensor signal into a signal suitable for line transmission as the output, and then transmits it to the instrument or other equipment through the line. Analog transmitters have been widely used in the field of industrial control for a long time. Their principles are simple and their manufacturing processes are mature. They have always had a considerable share in the field of sensor signal processing; however, the analog signal form of the analog transmitter with continuous values ​​also brings the disadvantage of weak anti-interference ability. The electrical signal will be interfered by various noises from the outside and inside the communication system during the transmission along the line. The noise and signal are difficult to separate after mixing, which reduces the communication quality. This problem is more prominent in long-distance signal transmission. The transmission line senses various interference signals along the way and superimposes them on the real signal, making it difficult for the terminal equipment to identify them efficiently and accurately. Utility Model Content

[0003] The technical problem to be solved by the utility model is: to overcome the defects of traditional analog output transmitter signal transmission being easily interfered and difficult to improve accuracy, and to provide a digital weighing sensor, which, under the premise of being able to output higher-precision digital signals, amplifies and compensates the sensor source signal collected at the front end before digital-to-analog conversion, and will not introduce interference and errors after digital processing, and can adjust and coordinate the accuracy and rate of the output signal as needed.

[0004] The digital weighing sensor comprises a signal processing circuit for digitally processing the front-end sensor signal and a digital communication circuit for data connection with the back-end instrument equipment, wherein the digital communication circuit is connected to the output end of the signal processing circuit, wherein the signal processing circuit is integrated with a processor, a UART differential input and output port module, a PGA amplifier, an ADC analog-to-digital conversion module, a Timer module, a WDT watchdog module, and an LDO linear voltage regulator module; the UART differential input and output port module is connected to the input end of the ADC analog-to-digital conversion module via the PGA amplifier, the output end of the ADC analog-to-digital conversion module is connected to the digital communication circuit via the processor, the Timer module and the WDT watchdog module are connected to the processor, the control end of the processor is respectively connected to the differential input and output port module, the PGA amplifier, and the ADC analog-to-digital conversion module, and the LDO linear voltage regulator module supplies power to each module on the signal processing circuit.

[0005] Furthermore, the digital communication unit includes an RS232 interface module and an RS485 interface module.

[0006] Specifically, the signal processing circuit adopts the JHM3802 processor.

[0007] Specifically, the RS232 interface module adopts a MAX232 communication chip, and the RS485 interface module adopts a MAX485C communication chip.

[0008] The utility model discloses a digital weighing sensor, which overcomes the defects of traditional analog output transmitter that signal transmission is easily disturbed and accuracy is difficult to improve. On the premise of being able to output digital signals with higher accuracy, the sensor source signal collected at the front end is amplified and compensated before digital-to-analog conversion, and no interference and error are introduced after digital processing. At the same time, the accuracy and rate of the coordinated output signal can be adjusted according to needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following is a further description of a digital weighing sensor of the utility model in conjunction with the accompanying drawings:

[0010] Figure 1 It is a wireframe diagram of the logic structure and connection principle of implementation mode 1 of the digital weighing sensor;

[0011] Figure 2 This is a circuit diagram of implementation mode 2 of the digital load cell.

[0012] In the figure:

[0013] 1- signal processing circuit; 11- processor, 12- UART differential input and output port module, 13- PGA amplifier, 14- ADC analog-to-digital conversion module, 15- Timer module, 16- WDT watchdog module, 17- LDO linear voltage regulator module;

[0014] 2-digital communication circuit; 21-RS232 interface module, 22-RS485 interface module. DETAILED DESCRIPTION

[0015] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0016] In the description of the present invention, it should be understood that the terms "left", "right", "front", "back", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0017] The technical solution of the utility model is further described below with specific embodiments, but the protection scope of the utility model is not limited to the following embodiments.

[0018] Implementation method 1: Figure 1 As shown, the digital weighing sensor includes a signal processing circuit 1 for digitally processing the front-end sensor signal and a digital communication circuit 2 for data connection with the back-end instrument equipment, wherein the digital communication circuit 2 is connected to the output end of the signal processing circuit 1, wherein:

[0019] The signal processing circuit 1 is integrated with a processor 11, a UART differential input and output port module 12, a PGA amplifier 13, an ADC analog-to-digital conversion module 14, a Timer module 15, a WDT watchdog module 16, and an LDO linear voltage regulator module 17; the UART differential input and output port module 12 is connected to the input end of the ADC analog-to-digital conversion module 14 via the PGA amplifier 13, and the output end of the ADC analog-to-digital conversion module 14 is connected to the digital communication circuit 2 via the processor 11, the Timer module 14 and the WDT watchdog module 15 are connected to the processor 11, and the control end of the processor 11 is respectively connected to the differential input and output port module 12, the PGA amplifier 13, and the ADC analog-to-digital conversion module 14, and the LDO linear voltage regulator module 17 supplies power to each module on the signal processing circuit 1. The digital communication unit 2 includes an RS232 interface module 21 and an RS485 interface module 22. Two levels of RS232 and RS485 are output, and the data format is Modbus standard.

[0020] Implementation method 2: Figure 2As shown, the signal processing circuit 1 of the digital weighing sensor adopts the JHM3802 processor. The RS232 interface module 21 adopts the MAX232 communication chip, and the RS485 interface module 22 adopts the MAX485C communication chip. JHM3802 is a 32-bit ARM processor with a Cortex M0+PGA core and internally integrated peripherals such as ADC, LDO, UART, Timer, and WDT. A single module can include the necessary functional modules in this design, reducing the coupling link between the processor and the peripherals and ensuring stable working conditions. The remaining structures and components are as described in Implementation 1 and will not be described again.

[0021] During operation: After the LDO supplies stable DC power, the Timer and WDT run, and the sensor bridge is sampled by the ARM processor using the UART. The differential signal of the sensor is input to the PGA through the UART for signal amplification, and then the analog-to-digital conversion is performed in the ADC, and the level signal is output to the digital communication circuit. The ARM processor controls the amplification factor of the PGA and adjusts the speed and accuracy of the ADC. The PGA amplifier is up to 72 times, and has nonlinear compensation and temperature compensation functions. The ADC conversion accuracy can reach 16-19 bits, and the speed can reach up to 1350Hz, thereby improving the signal conversion accuracy and efficiency.

[0022] This digital weighing sensor overcomes the defects of traditional analog output transmitter signal transmission that is easily interfered and difficult to improve accuracy. On the premise of being able to output higher-precision digital signals, it amplifies and compensates the sensor source signal collected at the front end before digital-to-analog conversion. After digital processing, it will no longer introduce interference and errors. At the same time, it can adjust and coordinate the accuracy and rate of the output signal as needed.

[0023] The above description shows the main features, basic principles, and advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments or embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, the above embodiments or embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the utility model. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0024] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A digital weighing sensor, characterized in that: It comprises a signal processing circuit (1) for digitally processing a front-end sensor signal and a digital communication circuit (2) for data connection with a back-end instrument device, wherein the digital communication circuit (2) is connected to the output end of the signal processing circuit (1), wherein: The signal processing circuit (1) is integrated with a processor (11), a UART differential input / output port module (12), a PGA amplifier (13), an ADC analog-to-digital conversion module (14), a Timer module (15), a WDT watchdog module (16), and an LDO linear voltage regulator module (17); the UART differential input / output port module (12) is connected to the input end of the ADC analog-to-digital conversion module (14) via the PGA amplifier (13), the output end of the ADC analog-to-digital conversion module (14) is connected to the digital communication circuit (2) via the processor (11), the Timer module (14) and the WDT watchdog module (16) are connected to the processor (11), the control end of the processor (11) is respectively connected to the differential input / output port module (12), the PGA amplifier (13), and the ADC analog-to-digital conversion module (14), and the LDO linear voltage regulator module (17) supplies power to each module on the signal processing circuit (1).

2. The digital weighing sensor according to claim 1 is characterized in that: The digital communication circuit (2) comprises an RS232 interface module (21) and an RS485 interface module (22).

3. The digital weighing sensor according to claim 2 is characterized in that: The signal processing circuit (1) adopts a JHM3802 processor.

4. The digital weighing sensor according to claim 3 is characterized in that: The RS232 interface module (21) adopts a MAX232 communication chip, and the RS485 interface module (22) adopts a MAX485C communication chip.

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