Bluetooth to RS485 serial port transceiver with switch

Abstract

The utility model provides an RS485 to Bluetooth wireless serial port data transmission transceiver which comprises an RS485 interface J1, an RS485 to TTL serial port chip U1, a serial port to Bluetooth processing chip U2, a Bluetooth antenna pedestal P1, a USB power supply port USB1, an LDO voltage reduction chip V1, a power supply switch control chip U5, an MOS switch tube Q1 and an LDO voltage reduction chip U4. The RS485 interface J1 is in communication connection with the RS485 to TTL serial port chip U1, the RS485 to TTL serial port chip U1 is in circuit connection with the serial port to Bluetooth processing chip U2, the USB power supply port USB1 is in circuit connection with the LDO step-down chip V1, the LDO step-down chip V1 is in circuit connection with the power supply switch control chip U5, the LDO step-down chip V1 is in circuit connection with the MOS switch tube Q1, and the power supply switch control chip U5 is in circuit connection with the MOS switch tube Q1. The serial port-to-Bluetooth data communication device is applied to a serial port-to-Bluetooth data communication scene, has a bidirectional transceiving function and a switch turn-off function, and is convenient for a plurality of hosts to perform many-to-one data switching communication by turning off Bluetooth.

Description

Technical Field

[0001] This utility model relates to the technical field of wireless serial port data communication products, specifically a Bluetooth to RS485 serial transceiver with a switch. Background Technology

[0002] Currently, Bluetooth wireless serial communication products are mainly applied in the form of modules. This method can be used in most device applications. However, since Bluetooth requires master-slave pairing to connect and communicate, it becomes cumbersome when disconnecting. The host needs to be configured and then canceled using a configuration tool to disconnect, and reconnection requires reconfiguration using the same tool. This makes selective communication inconvenient. For example, some Bluetooth-to-serial modules on the market require connection to pin headers or embedding on other circuit boards. This method of use greatly wastes Bluetooth communication resources, limiting communication to a fixed method. When selective communication is needed, it becomes cumbersome, requiring customers to spend time configuring or purchasing more Bluetooth serial ports for pairing. This fixed communication method is also quite wasteful of resources. Utility Model Content

[0003] The present invention aims to overcome the shortcomings of the prior art by providing a Bluetooth to RS485 serial transceiver with a switch, which is applied in wireless serial data communication scenarios. It has bidirectional transmission and reception functions, is easy to use, and reduces capital costs and material resources.

[0004] To achieve the above objectives, this utility model provides the following technical solution: 1. A Bluetooth to RS485 serial transceiver with a switch, wherein the RS485 to Bluetooth wireless serial data transmission transceiver includes an RS485 interface J1, an RS485 to TTL serial chip U1, a serial to Bluetooth processing chip U2, a Bluetooth antenna mount P1, a USB power supply port USB1, an LDO step-down chip V1, a power supply switch control chip U5, a MOS switch Q1, and an LDO step-down chip U4;

[0005] The RS485 interface J1 is communicatively connected to the RS485 to TTL serial port chip U1.

[0006] The RS485 to TTL serial port chip U1 and the serial port to Bluetooth processing chip U2 are connected by a circuit.

[0007] The serial-to-Bluetooth processing chip U2 is the main functional chip for serial-to-Bluetooth conversion. The serial-to-Bluetooth processing chip U2 mainly exchanges serial data with the RS485 to TTL serial port chip U1 and controls the enable switch of the RS485 to TTL serial port chip U1.

[0008] The ANT pin of the serial-to-Bluetooth processing chip U2 is connected to the Bluetooth antenna mount P1.

[0009] The USB power supply port USB1 is connected to the LDO step-down chip V1 circuit;

[0010] The LDO step-down chip V1 is connected to the power supply switch control chip U5 circuit.

[0011] The LDO step-down chip V1 is connected to the source (S) of the MOS switch Q1, where S is the source of the MOS switch.

[0012] The power supply switch control chip U5 is connected to the gate circuit of the MOS switch Q1. Pin 1 of the power supply switch control chip U5 is connected to a tactile switch through a resistor R181 K. The other pin of the tactile switch is grounded.

[0013] The MOS switch Q1 is connected to the power input pin 3 of the LDO buck chip U4.

[0014] The LDO step-down chip U4 is connected to the power input pin 5 of the serial-to-Bluetooth processing chip U2. Pin 2 of the LDO step-down chip U4 is the power output pin after voltage reduction, outputting a voltage of 3.3V. The LDO step-down chip U4 supports a voltage input of 5V and obtains a fixed voltage of 3.3V after voltage reduction.

[0015] Furthermore, the RS485 interface J1 is connected to the RS485 to TTL serial port chip U1 via pins "RS485_A" and "RS485_B".

[0016] Furthermore, when processing TLL serial port signals, the serial port to Bluetooth processing chip U2 needs to convert them to Bluetooth protocol at the same time. Bluetooth needs to be paired for use. Bluetooth can be set as a master or slave. When set as a master, it actively sends commands. When set as a slave, it receives commands from the master and returns commands to the master. Whether it is a master or a slave, it can be a computer or a device.

[0017] Furthermore, the ANT pin of the serial-to-Bluetooth processing chip U2 is connected to the Bluetooth antenna mount P1.

[0018] Furthermore, the USB power supply port USB1 will supply power to the switch control chip U5, and also supply power to the source terminal of the MOS switch Q1, with a supply voltage of 5V.

[0019] Furthermore, the LDO step-down chip U4 supplies power to the serial-to-Bluetooth processing chip U2.

[0020] This utility model provides a Bluetooth to RS485 serial transceiver with a switch, which has the following advantages:

[0021] The advantages of this invention are that the product supports broadcast mode, host mode and slave mode, supports Bluetooth BLE4.2, supports serial port AT configuration and Bluetooth communication configuration in slave mode, supports MODEM handshake signal, supports Bluetooth adapter and serial port Bluetooth communication, supports Bluetooth host connection to Windows / Linux / Android / iOS and other systems, has a low power mode, and the transmission power can be adjusted in multiple levels through AT configuration.

[0022] This utility model provides a high-performance and low-cost solution for complex environments where on-site wiring is not possible. It is a long-distance wireless communication solution with the most prominent features of long distance and low power consumption, breaking through the coverage scenarios that previously required wiring. This product uses the 2.4G wireless frequency band for wireless data transmission by default.

[0023] The application and uses of this utility model in serial port data communication scenarios are as follows:

[0024] 1. Remote control and data transmission of IoT devices: With BLESeial, you can enable serial communication between embedded devices (such as Raspberry Pi) and smartphones or other hosts.

[0025] 2. Real-time data monitoring: In the experimental environment, BLE sensor data is transmitted to the computer in real time using BLE sensor data, which facilitates data analysis.

[0026] 3. Remote device debugging: For widely distributed devices, BLESeial can be used as a wireless debugging interface, allowing for remote debugging without the need for physical cables. Attached Figure Description

[0027] Figure 1 This is a block diagram illustrating the serial data transmission principle of a Bluetooth-to-RS485 serial transceiver with a switch according to this utility model.

[0028] Figure 2 This is a block diagram illustrating the serial port data receiving principle of a Bluetooth-to-RS485 serial transceiver with a switch according to this utility model.

[0029] Figure 3 This is a serial port data circuit diagram of a Bluetooth to RS485 serial transceiver with a switch according to this utility model.

[0030] Figure 4 This is the data circuit diagram of the Bluetooth to serial port circuit of this utility model.

[0031] Figure 5 This is the data circuit diagram of the serial communication circuit of this utility model.

[0032] Figure 6 This is a data circuit diagram of the USB power supply circuit of this utility model.

[0033] Figure 1-6 The components are: 1. RS485 interface J1; 2. RS485 to TTL serial port chip U1; 3. Serial port to Bluetooth processing chip U2; 4. Bluetooth antenna mount P1; 5. USB power supply port USB1; 6. LDO step-down chip V1; 7. Power supply switch control chip U5; 8. MOS switch Q1; 9. LDO step-down chip U4. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0035] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0036] This application provides a Bluetooth-to-RS485 serial transceiver with a switch. The following provides a detailed description of this Bluetooth-to-RS485 serial transceiver with a switch. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0037] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0038] Please see Figure 1-6This embodiment provides a Bluetooth to RS485 serial transceiver with a switch, an RS485 to Bluetooth wireless serial data transmission transceiver, including an RS485 interface J11, an RS485 to TTL serial chip U12, a serial to Bluetooth processing chip U23, a Bluetooth antenna mount P14, a USB power supply port USB15, an LDO step-down chip V16, a power supply switch control chip U57, a MOS switch Q18, and an LDO step-down chip U49;

[0039] Among them, the RS485 interface J11 is connected to the RS485 to TTL serial port chip U12. The RS485 signal of the industrial equipment or computer is connected to the RS485 interface J11 to transmit half-duplex RS485_A and RS485_B serial port signals. This interface sends and receives RS485 signals in real time, and is also connected to pins 6 and 7 of the RS485 to TTL serial port chip U12.

[0040] The RS485 to TTL serial port chip U12 and the serial port to Bluetooth processing chip U23 are connected by a circuit. The RS485 to TTL serial port chip U12 is an RS485 transceiver chip that converts RS485 to TTL signals. This chip can convert full-duplex TXD and RXD signals into half-duplex RS485 signals, and it can also convert half-duplex RS485 signals into full-duplex TXD and RXD signals. Since the serial port to Bluetooth processing chip U23 can only communicate with TTL signals, the RS485 to TTL serial port chip U12 is mainly responsible for the signal conversion between the two levels.

[0041] Among them, the serial-to-Bluetooth processing chip U23 is the main functional chip for serial-to-Bluetooth conversion. This chip primarily exchanges serial data with the RS485-to-TTL serial chip U12 and controls the enable switch of the RS485-to-TTL serial chip U12. When the TXD signal is transmitted by the serial-to-Bluetooth processing chip U23, the chip's RTS# / TNOW pin outputs a high level to pins 2 and 3 of the RS485-to-TTL serial chip U12, enabling the RS485-to-TTL serial chip... When the transmit channel of chip U12 is opened, the RS485 signal of RS485 to TTL serial port chip U12 is sent out. When the RXD of serial port to Bluetooth processing chip U23 receives the signal, the RTS# / TNOW pin of the chip outputs a low level to pins 2 and 3 of RS485 to TTL serial port chip U12, which closes the transmit channel of RS485 to TTL serial port chip U12, so that the RS485 signal of chip U1 is received back. This cycle repeats to achieve data transmission and reception communication.

[0042] Among them, the ANT pin of the serial port to Bluetooth processing chip U23 is connected to the Bluetooth antenna mount P14. When the serial port to Bluetooth processing chip U23 receives or sends signals, it performs protocol conversion on these serial port signals and converts them into Bluetooth signals for transmission. At the same time, Bluetooth also has full-duplex communication and can receive paired Bluetooth signals. Whether sending or receiving, the Bluetooth antenna mount P14 is responsible for transmitting and receiving signals.

[0043] Among them, the USB power supply port USB15 is connected to the LDO step-down chip V16 circuit. The product provides a USB-C power supply interface for chip power supply. Pin 1 of the USB power supply port USB15 interface is VCC power supply, and pins 4 and 5 are grounded and connected to the entire ground of the product. The power input pin 3 of the LDO step-down chip V16 is connected to pin 1 of the USB power supply port USB1 interface, thus realizing the requirement of external power supply input.

[0044] The LDO step-down chip V16 is connected to the power switch control chip U57. Pin 1 of the LDO step-down chip V16 is the power output pin. After being stepped down, the subsequent circuits receive a suitable voltage before they can operate normally. The LDO step-down chip V16 can meet the power input of 5-12V and step it down to 5V output. This voltage is sent to pin 5 of the power switch control chip U57. After being powered on, the power switch control chip U57 operates normally and waits for control commands.

[0045] Among them, the LDO step-down chip V16 is also connected to the S-terminal circuit of the MOS switch Q18. The S-terminal is the source of the MOS transistor, the power input pin, which waits for the control signal to turn off.

[0046] The power supply switch control chip U57 is connected to the gate (G) of the MOS switch Q18. Pin 1 of the power supply switch control chip U57 is connected to a tactile switch through resistor R181 K. The other pin of the switch is grounded. Each time the switch is turned on and off, pin 3 of the power supply switch control chip U57 will change between high and low levels once. The level is in a holding state. Pin 3 of the power supply switch control chip U57 is connected to the gate (G) of the MOS switch Q18 through resistors R20100R and R110R. The gate (G) receives a high or low level, and the drain (D) of the MOS switch Q18 receives the output voltage. The drain (D) is the gate of the MOS transistor. When the gate (G) is low, the current from the source (S) will flow into the drain (D) to output voltage. When the gate (G) is high, the current from the source (S) cannot flow into the drain (D) because the MOS transistor is in the off state, so the drain (D) cannot output voltage.

[0047] Among them, the MOS switch Q18 is connected to the power input pin 3 of the LDO buck chip U49. Since the gate of the MOS switch Q18 is given a high or low level, the source of the MOS switch Q18 receives the input voltage, thereby the drain of the MOS switch Q18 outputs the control voltage to the power input pin 3 of the LDO buck chip U49.

[0048] The LDO step-down chip U49 is connected to the power input pin 5 of the serial-to-Bluetooth processing chip U23. Pin 2 of the LDO step-down chip U49 is the power output pin after voltage reduction, outputting a voltage of 3.3V. The LDO step-down chip U49 supports a 5V voltage input, and after reduction, a fixed voltage of 3.3V is obtained. This voltage meets the power supply requirements of the serial-to-Bluetooth processing chip U23, enabling the serial-to-Bluetooth processing chip U23 to work normally.

[0049] Among them, the RS485 interface J11 is connected to the RS485 to TTL serial port chip U12 via the pins "RS485_A, RS485_B". The RS485 to TTL serial port chip U12 is responsible for sending and receiving the "RS485_A, RS485_B" signals, and converting the TTL signals "H_ATX and H_ARX" sent and received by the serial port to Bluetooth processing chip U23. The RS485 to TTL serial port chip U12 converts the TTL level signals into RS485 signals, thereby satisfying the access of RS485 signals.

[0050] The serial-to-Bluetooth processing chip U23, when processing TTL serial signals, needs to simultaneously convert them to the Bluetooth protocol. Bluetooth requires pairing and can be set as a master or slave device. When set as a master, it actively sends commands; when set as a slave, it receives commands from the master and returns commands to the master. Both the master and slave devices can be computers or other devices. When the master sends commands, it transmits the signal through the RS485 interface J11 to the RS485-to-TTL serial chip U12. The RS485-to-TTL serial chip U12 converts the signal into a TTL signal and sends it to the serial-to-Bluetooth processing chip U23. The serial-to-Bluetooth processing chip U23 then performs internal protocol conversion and converts the signal into a Bluetooth wireless signal for transmission. The slave device receives commands in the reverse process. After receiving the Bluetooth signal, the slave device needs to convert the Bluetooth chip protocol to a TTL signal. The TTL signal is then converted back to an RS485 signal by the RS485-to-TTL serial chip U12. When the device receives the RS485 signal, it may or may not return a command to the master. The return process is the same as the master's command sending process.

[0051] The ANT pin of the serial-to-Bluetooth processing chip U23 is connected to the Bluetooth antenna mount P14. Since Bluetooth is a wireless transmission signal, an antenna mount is needed to fix the antenna accessories. The Bluetooth antenna is responsible for receiving or sending Bluetooth signals from the host or slave device.

[0052] The USB15 power port inputs DC power voltage, which is supplied to the LDO step-down chip V16 to meet the input of 12V or 5V power supply. The voltage after step-down is 5V, and the chip can operate normally with the voltage of the subsequent circuit.

[0053] The LDO step-down chip V16 supplies power to the switch control chip U57 and also to the source (S) terminal of the MOSFET Q18. The supply voltage is 5V. When the voltage is supplied to the switch control chip U57, the switch control chip U57 has a switch control pin. When SW1 touches the switch once, the voltage level of pin 3 of the switch control chip U57 changes once. When powered on, it is at a high level; after SW1 is pressed once, the voltage level of pin 3 of the switch control chip U57 becomes a low level. Thus, each press changes the voltage level, and this change in high and low level is supplied to the gate (G) terminal of the MOSFET Q18, thereby controlling the drain (D) terminal of the MOSFET Q18. The main purpose of the switch control chip U57 and MOS switch Q18 here is to control the power supply status of the subsequent circuit through the SW1 switch. Each press of SW1 will turn the subsequent power supply circuit on or off. The subsequent power supply circuit includes an LDO step-down chip U49 and a serial-to-Bluetooth processing chip U23. Therefore, the function of the SW1 switch here is to turn on the power supply to the serial-to-Bluetooth processing chip U23 and turn it off. When the serial-to-Bluetooth processing chip U23 is not needed, SW1 is used to switch it to the off state, and when it is needed, the power supply is turned on.

[0054] Bluetooth typically operates in a master-slave mode. When multiple masters are connected to a slave device, the first master to successfully connect will communicate with the slave device. When we need to specify a particular master, the SW1 switch comes into play, turning off the unnecessary masters and only turning on the master that needs to communicate.

[0055] The purpose of the LDO step-down chip U49 is to power the serial-to-Bluetooth processing chip U23. It inputs a 5V voltage to the LDO step-down chip U49 through the drain of the MOS switch Q19. After stepping down, the LDO step-down chip U49 outputs a 3.3V voltage to the Bluetooth processing chip U23. Since the Bluetooth chip needs to support a voltage of 3.3V, whether the LDO step-down chip U49 has a voltage output will directly affect the working state of the Bluetooth processing chip U23.

[0056] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0057] The foregoing has provided a detailed description of a Bluetooth-to-RS485 serial transceiver with a switch provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A Bluetooth-to-RS485 serial transceiver with a switch, characterized in that... The RS485 to Bluetooth wireless serial data transmission transceiver includes an RS485 interface J1 (1), an RS485 to TTL serial port chip U1 (2), a serial port to Bluetooth processing chip U2 (3), a Bluetooth antenna mount P1 (4), a USB power supply port USB1 (5), an LDO step-down chip V1 (6), a power supply switch control chip U5 (7), a MOS switch Q1 (8), and an LDO step-down chip U4 (9). The RS485 interface J1(1) is connected to the RS485 to TTL serial port chip U1(2) for communication. The RS485 to TTL serial port chip U1(2) and the serial port to Bluetooth processing chip U2(3) are connected by a circuit. The serial-to-Bluetooth processing chip U2(3) is the main functional chip for serial-to-Bluetooth conversion. The serial-to-Bluetooth processing chip U2(3) mainly exchanges serial data with the RS485 to TTL serial port chip U1(2) and controls the enable switch of the RS485 to TTL serial port chip U1(2). The ANT pin of the serial-to-Bluetooth processing chip U2(3) is connected to the Bluetooth antenna mount P1(4) in a circuit. The USB power supply port USB1(5) is connected to the LDO step-down chip V1(6) circuit; The LDO step-down chip V1(6) is connected to the power supply switch control chip U5(7) in a circuit. The LDO step-down chip V1(6) is connected to the source circuit of the MOS switch Q1(8), and the source is the source of the MOS transistor. The power supply switch control chip U5(7) is connected to the gate circuit of the MOS switch Q1(8). The first pin of the power supply switch control chip U5(7) is connected to a tactile switch through the resistor R181 K. The other pin of the tactile switch is grounded. The MOS switch Q1 (8) is connected to the power input pin 3 of the LDO step-down chip U4 (9); The LDO step-down chip U4 (9) is connected to the power input pin 5 of the serial-to-Bluetooth processing chip U2 (3). Pin 2 of the LDO step-down chip U4 (9) is the power output pin after step-down, outputting a voltage of 3.3V. The LDO step-down chip U4 (9) supports a voltage input of 5V, and a fixed voltage of 3.3V is obtained after step-down.

2. The Bluetooth-to-RS485 serial transceiver with a switch according to claim 1, characterized in that: The RS485 interface J1(1) is connected to the RS485 to TTL serial port chip U1(2) via pins "RS485_A, RS485_B".

3. A Bluetooth-to-RS485 serial transceiver with a switch according to claim 1, characterized in that... The serial-to-Bluetooth processing chip U2(3) needs to convert the TLL serial port signal into the Bluetooth protocol at the same time. Bluetooth needs to be paired. Bluetooth can be set as a host or a slave. When set as a host, it actively sends instructions. When set as a slave, it receives instructions from the host and returns instructions to the host. Whether it is a host or a slave, it can be a computer or a device.

4. A Bluetooth-to-RS485 serial transceiver with a switch according to claim 1, characterized in that... The ANT pin of the serial-to-Bluetooth processing chip U2(3) is connected to the Bluetooth antenna mount P1(4).

5. A Bluetooth-to-RS485 serial transceiver with a switch according to claim 1, characterized in that... The USB power supply port USB1(5) will receive DC power voltage.

6. A Bluetooth-to-RS485 serial transceiver with a switch according to claim 1, characterized in that... The LDO step-down chip V1 (6) will supply power to the switch control chip U5 (7) and also supply power to the source of the MOS switch Q1 (8), with a supply voltage of 5V.

7. A Bluetooth-to-RS485 serial transceiver with a switch according to claim 1, characterized in that... The LDO step-down chip U4 (9) supplies power to the serial-to-Bluetooth processing chip U2 (3).

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