Hardware circuit of 23-bit photoelectric absolute value encoder

Abstract

The utility model relates to a hardware circuit of a 23-bit photoelectric absolute value encoder, which belongs to the technical field of encoders and specifically comprises a photocell circuit used for performing photoelectric conversion on incident light and outputting analog signals to a singlechip processing circuit; the single chip microcomputer processing circuit is used for carrying out AD conversion and position calculation on the input analog signal and outputting a position signal to the communication circuit; the communication circuit is used for communicating with an upper computer and sending the position signal transmitted by the single chip microcomputer processing circuit to the upper computer; the storage circuit is used for providing a space for storing calibration parameters and position data for the single chip microcomputer processing circuit; and the power supply circuit is used for supplying power to the photocell circuit, the singlechip processing circuit, the communication circuit and the storage circuit. According to the utility model, through the reasonable design of each circuit, the limitation of the traditional split type structure on the miniaturization of the encoder is broken through, the axial space size of the encoder is compressed, and the problem of resolution attenuation caused by multi-code-channel crosstalk is thoroughly solved.

Description

Technical Field

[0001] This utility model relates to the field of encoder technology, and in particular to the hardware circuit of a 23-bit photoelectric absolute encoder. Background Technology

[0002] Photoelectric absolute encoders achieve direct output of shaft angular position through code disk grating projection and photoelectric sensor conversion, offering advantages such as immediate position upon power-on and strong anti-interference capabilities, and are widely used in industrial positioning applications. However, with the demand for ultra-high resolution of 23 bits and above, traditional photoelectric absolute encoder hardware circuit design solutions face numerous challenges:

[0003] (1) Optical path design defects:

[0004] For multi-track stacked structures (such as 3-5 tracks), the complexity of the photolithography process increases exponentially, and the yield of the code disk decreases significantly.

[0005] Crosstalk between multiple optical paths severely degrades the signal-to-noise ratio (SNR).

[0006] (2) Spatial structural limitations:

[0007] The "split" layout of the light source and photoelectric sensor on opposite sides of the slit results in a large axial length of the encoder, which hinders its miniaturization and limits the application of photoelectric absolute encoders in confined space scenarios. Utility Model Content

[0008] Therefore, it is necessary to provide a hardware circuit for a 23-bit photoelectric absolute encoder to address the problems faced by traditional photoelectric absolute encoder hardware circuit design schemes.

[0009] To solve the above problems, the present invention adopts the following technical solution:

[0010] A hardware circuit for a 23-bit photoelectric absolute encoder, comprising:

[0011] Photovoltaic cell circuit is used to convert incident light into photoelectric signals and output analog signals to the microcontroller processing circuit.

[0012] The microcontroller processing circuit uses a GD32E103T8 microcontroller to perform AD conversion and position calculation on the input analog signal, and outputs the position signal to the communication circuit.

[0013] The communication circuit is used to communicate with the host computer and send the position signal transmitted from the microcontroller processing circuit to the host computer.

[0014] The storage circuit provides space for the microcontroller processing circuit to store calibration parameters and position data.

[0015] The power supply circuit is used to power the photovoltaic cell circuit, the microcontroller processing circuit, the communication circuit, and the storage circuit.

[0016] The beneficial effects of this utility model are as follows: Through the rational design of the photovoltaic cell circuit, the microcontroller processing circuit, the communication circuit, the storage circuit and the power supply circuit, this utility model breaks through the limitations of the traditional split structure on miniaturization, compresses the axial space size of the encoder, and at the same time, uses the processing circuit based on the GD32E103T8 microprocessor to perform high-precision AD conversion and real-time position calculation, achieving high resolution (23 bits) and completely solving the resolution attenuation problem caused by crosstalk of multiple code channels. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the hardware circuit described in this utility model;

[0018] Figure 2 This is a structural diagram of a microcontroller processing circuit;

[0019] Figure 3 This is a structural diagram of a communication circuit;

[0020] Figure 4 The circuit diagram of the AT24C16 memory;

[0021] Figure 5 The circuit diagram of the K24C02 memory is shown below.

[0022] Figure 6 This is a structural diagram of the power supply circuit;

[0023] Figure 7 The circuit diagram is for preventing reverse connection. Detailed Implementation

[0024] The technical solution of this utility model will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0025] See Figure 1 This utility model proposes a hardware circuit for a 23-bit photoelectric absolute encoder, which includes a photovoltaic cell circuit, a microcontroller processing circuit, a communication circuit, a storage circuit, and a power supply circuit.

[0026] Specifically, the photovoltaic cell circuit is used to perform photoelectric conversion on the light reflected from the code disk and output an analog signal to the microcontroller processing circuit for processing. The photovoltaic cell circuit can be implemented using existing high-resolution optical reflective absolute encoder chips, such as the IC-SH2656 chip. The power supply pin AVCC of the IC-SH2656 chip is connected to a 5V input voltage, and the signal output pins are SCLK PA2, MISO PA1, and MOSIPA0.

[0027] The microcontroller processing circuit uses a GD32E103T8 microcontroller to perform AD conversion and position calculation on the input analog signal, thereby outputting the position signal to the communication circuit.

[0028] The input pins SCLK, MISO, and MOSI of the GD32E103T8 microcontroller are connected to the output pins SCLK PA2, MISO PA1, and MOSIPA0 of the photovoltaic cell circuit through resistors (R23, R24, and R25), respectively. The PA9 output pin of the GD32E103T8 microcontroller is connected to the TXD pin of the communication circuit through a 330Ω resistor (R6), and the PA10 pin is connected to the RXD pin of the communication circuit through a 1kΩ resistor (R5) to achieve serial communication with the communication circuit.

[0029] The microcontroller processing circuit also includes a reset circuit. The NRST pin of the GD32E103T8 microcontroller is connected to the input voltage (3.3V) through resistor R10. A capacitor C3 is placed between the NRST pin and resistor R10. One end of capacitor C3 is connected to both the NRST pin and resistor R10, and the other end is connected to GND. For the detailed pinout of the GD32E103T8 microcontroller, please refer to [link to pinout diagram]. Figure 2 This will not be elaborated upon here.

[0030] The communication circuit is used to communicate with the microcontroller processing circuit and the host computer respectively, and to send the position signal transmitted from the microcontroller processing circuit to the host computer for display.

[0031] like Figure 3 As shown, the communication circuit in this embodiment can be an RS485 bus circuit based on the MAX485 chip, wherein the RO pin and DI pin of the MAX485 chip are connected to the RXD pin and TXD pin of the communication circuit, respectively.

[0032] The RXD and TXD pins of the communication circuit are connected to the RO and DI pins of the MAX485 chip, respectively. The RE and DE pins are enable pins, connected to the PA11 pin in the microcontroller processing circuit, used to control the transmit and receive states of the communication circuit through high and low levels. Pins A and B are the differential signal receiver and transmitter, respectively, both connected to the input terminals of the host computer. A lightning protection circuit is provided between the MAX485 chip and the host computer. This lightning protection circuit uses a pair of TVS diodes (D3, D4) and two capacitors (C21, C22). For details, please refer to [link to relevant documentation]. Figure 3 The TVS tube used is the SMF12CA from MicroCommercial Components.

[0033] The storage circuit provides space for the microcontroller processing circuit to store calibration parameters and location data.

[0034] In this embodiment, the storage circuit uses a dual EEPROM memory, which includes an AT24C16 memory for storing dynamic calibration data (e.g., ...). Figure 4 (as shown) and the K24C02 memory for storing static data (such as Figure 5 (As shown).

[0035] The power supply circuit powers the photovoltaic cell circuit, microcontroller processing circuit, communication circuit, and storage circuit. The photovoltaic cell circuit operates at 5V, while the microcontroller processing circuit, communication circuit, and storage circuit all operate at 3.3V. Therefore, the power supply circuit uses the LR1107-3.3V chip, a low-dropout (LDO) regulator, to stably convert the 5V input voltage to a 3.3V output voltage, thus providing 3.3V power to the microcontroller processing circuit, communication circuit, and storage circuit. The structure of the power supply circuit is as follows. Figure 6 As shown.

[0036] Furthermore, the power supply circuit includes a reverse connection protection circuit, such as... Figure 7 As shown, the reverse connection protection circuit is composed of an SI2301DS field-effect transistor. The gate of the field-effect transistor is grounded through a 120Ω resistor, the source is connected to a 5V input voltage, and the drain is output to the power supply circuit to achieve power polarity protection and prevent the power supply from being connected in reverse.

[0037] This invention overcomes the limitations of traditional split structures on miniaturization by rationally designing the photovoltaic cell circuit, microcontroller processing circuit, communication circuit, storage circuit, and power supply circuit. It compresses the axial space size of the encoder and utilizes a processing circuit based on the GD32E103T8 microprocessor to perform high-precision AD conversion and real-time position calculation, achieving high resolution (23-bit) and completely solving the resolution attenuation problem caused by crosstalk from multiple code channels.

[0038] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A hardware circuit for a 23-bit photoelectric absolute encoder, characterized in that, include: Photovoltaic cell circuit is used to convert incident light into photoelectric signals and output analog signals to the microcontroller processing circuit. The microcontroller processing circuit uses a GD32E103T8 microcontroller to perform AD conversion and position calculation on the input analog signal, and outputs the position signal to the communication circuit. The communication circuit is used to communicate with the host computer and send the position signal transmitted from the microcontroller processing circuit to the host computer. The storage circuit provides space for the microcontroller processing circuit to store calibration parameters and position data. The power supply circuit is used to power the photovoltaic cell circuit, the microcontroller processing circuit, the communication circuit, and the storage circuit.

2. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 1, characterized in that, The power supply circuit includes a reverse connection protection circuit, which is composed of an SI2301DS field-effect transistor. The gate of the field-effect transistor is grounded through a 120Ω resistor, the source is connected to a 5V input voltage, and the drain is output to the power supply circuit to achieve power polarity protection.

3. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 2, characterized in that, The power supply circuit converts the 5V input voltage to a 3.3V system voltage to power the microcontroller processing circuit, communication circuit, and storage circuit.

4. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 1 or 2, characterized in that, The communication circuit uses an RS485 bus circuit based on the MAX485 chip.

5. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 4, characterized in that, The RXD and TXD pins of the communication circuit are connected to the RO and DI pins of the MAX485 chip, respectively.

6. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 4, characterized in that, The communication circuit includes a lightning protection circuit, which is implemented using a pair of TVS diodes.

7. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 6, characterized in that, The TVS tube model is SMF12CA.

8. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 1 or 2, characterized in that, The storage circuit uses a dual EEPROM memory, which includes an AT24C16 memory for storing dynamic calibration data and a K24C02 memory for storing static data.

9. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 1 or 2, characterized in that, The microcontroller processing circuit is equipped with a reset circuit. The NRST pin of the GD32E103T8 microcontroller is connected to the input voltage through a resistor R10. A capacitor C3 is provided between the NRST pin and the resistor R10. One end of the capacitor C3 is connected to the NRST pin and the resistor R10 respectively, and the other end is connected to GND.

10. The hardware circuit of a 23-bit photoelectric absolute encoder according to claim 1 or 2, characterized in that, The input pins SCLK, MISO, and MOSI of the GD32E103T8 microcontroller are connected to the output pins SCLKPA2, MISOPA1, and MOSIPA0 of the photovoltaic cell circuit through a 51Ω resistor.

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