A layered decoupling-based power carrier LED lamp string control method

Abstract

A hierarchical decoupling-based power line carrier LED string control method includes: a central controller generating a serial data stream containing data for at least one LED string; distributing the serial data stream to multiple nodes via a first communication network operating based on a differential serial communication protocol or a single-ended serial communication protocol; each node's local driver receiving the data stream, without parsing the LED animation control data, only performs protocol encapsulation and signal format conversion, generating a power line adaptation modulation signal and injecting it into the local power line, allowing the connected LED strings to respond to the signal and display the corresponding animation effect. This solution uses a hierarchical decoupling architecture to achieve high-precision synchronous control of long-distance, large-scale LED strings, effectively simplifying wiring and reducing construction complexity.

Description

Technical Field

[0001] This disclosure relates to the field of LED lighting control technology, and in particular to a hierarchical decoupling-based power line carrier LED string control method. The method employs a hierarchical decoupling architecture to improve reliability, making it suitable for large-scale synchronously animated LED string control and compatible with mainstream control protocols. Background Technology

[0002] In the field of LED decorative lighting, the application of large-scale programmable LED light strings is becoming increasingly widespread. The core technical challenge lies in how to achieve low-cost, long-distance, highly reliable, and precisely synchronized dynamic control of tens of thousands of independent LED beads.

[0003] Power line communication (PLC) technology has become a popular solution due to its ability to transmit data using existing power lines without requiring additional communication cables, thus simplifying construction. However, this solution employs an architecture of a main controller and multiple sub-controllers. The main controller sends control signals to the sub-controllers via the power lines, and the sub-controllers then drive their respective LED light strings.

[0004] The problem lies in the fact that solutions relying entirely on power line carrier as the backbone communication network generally face inherent physical bottlenecks: power lines, as a communication medium, have a harsh channel environment, are susceptible to noise interference, and have variable impedance, resulting in low speeds, high latency, and poor reliability over long distances. To compensate for signal attenuation, the system often needs to deploy a large number of sub-controllers with signal demodulation and processing capabilities. This not only significantly increases hardware costs, system complexity, and construction costs, but also makes precise animation synchronization between large-scale LED strings extremely difficult, making it unsuitable for controlling long-distance, large-scale, synchronously animated LED strings. Furthermore, in existing technologies, dedicated PLC systems such as pure power line carrier (PLC) control systems are often incompatible with mainstream industry control protocols such as DMX512, limiting their application scope.

[0005] It can be observed that this existing technology is a single-layer coupled or flattened control architecture based on power line communication (PLC), attempting to solve both long-distance transmission and driving problems simultaneously using PLC technology. Essentially, it is a functionally coupled single-layer architecture. In this existing architecture, the power line serves as both the backbone communication network and the final driving power source. The main controller modulates the signal containing animation instructions and injects it into the power line. Multiple sub-controllers distributed throughout the power line must first complete complex signal demodulation from the noisy power line, then fully parse the received instructions, and then call the pre-set animation algorithm in their firmware to generate the corresponding LED driving data locally, finally driving the connected light string.

[0006] Existing technologies based on single-layer coupling or flattened power line communication (PLC) control architectures suffer from the following technical problems: Due to poor power line channel quality, each sub-controller must integrate a processor, memory, and separate power supply and coupling circuitry to run complete demodulation and animation generation algorithms, resulting in high costs for individual nodes; each time a string of lights is added, an intelligent sub-controller needs to be added, causing the total system cost to increase linearly; the increase in sub-controllers and branches makes it extremely difficult to achieve frame-level precise synchronization of light strings across multiple sub-controllers; and the use of proprietary protocols to optimize anti-interference performance makes it difficult to interface with industry standard control protocols such as DMX512 and Art-Net, limiting their application in professional scenarios.

[0007] Therefore, there is an urgent need in this field for a new control solution that can reliably synchronize LED light strings on a large scale and is compatible with mainstream industry control protocols, and preferably can also ensure reliability in long-distance scenarios. Summary of the Invention

[0008] The purpose of this disclosure is to overcome the above-mentioned shortcomings of the prior art and to provide a power line carrier LED string control system and method based on hierarchical decoupling.

[0009] This disclosure reveals a power line carrier LED string control system based on hierarchical decoupling, including:

[0010] Central controller;

[0011] The first communication network operates based on a differential serial communication protocol or a single-ended serial communication protocol and is communicatively connected to the central controller.

[0012] A plurality of local drive devices, each of which is communicatively connected to the first communication network and electrically connected to a local power line, and each of the local drive devices includes:

[0013] The bus interface unit is communicatively connected to the first communication network.

[0014] The signal processing unit is communicatively connected to the bus interface unit;

[0015] A power line coupling unit, electrically connected to the signal processing unit and the local power line; and

[0016] The at least one LED string is electrically connected to the local power line.

[0017] Furthermore, the first communication network is a differential serial communication bus network based on the RS485 or RS422 standard; or, the first communication network is a single-ended serial communication bus network based on the TTL, LVTTL, CMOS, LVCMOS, or RS232 standard.

[0018] Furthermore, the signal processing unit includes a microcontroller (MCU), which is also connected to a non-volatile memory for storing the device address of the local driving device.

[0019] Furthermore, the power line coupling unit includes a signal isolation transformer and a coupling capacitor.

[0020] Furthermore, the local drive device also includes a status monitoring unit for monitoring the electrical parameters of the local power line or the operating status of the LED string, and reporting it to the central controller through the bus interface unit and the first communication network.

[0021] Furthermore, when the first communication network is a single-ended serial communication bus network based on TTL, LVTTL, CMOS, LVCMOS, or RS232 standards,

[0022] The first communication network includes a signal enhancement unit, which is connected in series or in parallel to the conductors of the first communication network.

[0023] Furthermore, the signal enhancement unit includes a bus driver, which is located at the signal output terminal of the central controller.

[0024] Furthermore, the signal enhancement unit includes a level converter.

[0025] Furthermore, the power line coupling unit includes a power line carrier modulation chip.

[0026] Furthermore, the physical topology of the first communication network is bus, star, or ring.

[0027] The cables of the first communication network are twisted-pair cables or three-core cables. When they are three-core cables, the three-core cables include a power line, a ground line, and a signal line.

[0028] Furthermore, this disclosure also reveals a power line carrier LED string control system based on hierarchical decoupling, comprising:

[0029] A central controller for generating a serial data stream containing data for at least one string of LEDs;

[0030] The first communication network operates based on a differential serial communication protocol or a single-ended serial communication protocol and is communicatively connected to the central controller for distributing the serial data stream among multiple nodes.

[0031] A plurality of local drive devices, each of which is communicatively connected to the first communication network and electrically connected to a local power line, and each of the local drive devices includes:

[0032] A bus interface unit is configured to receive the serial data stream from the first communication network;

[0033] The signal processing unit, which is communicatively connected to the bus interface unit, is configured not to parse the LED animation control data in the serial data stream, but to directly perform protocol encapsulation or signal format conversion to generate a modulated signal suitable for transmission on the power line.

[0034] A power line coupling unit, electrically connected to the signal processing unit and the local power line, is configured to inject the modulated signal into the local power line; and...

[0035] The at least one LED string is electrically connected to the local power line and is configured to display a corresponding LED animation effect in response to the modulation signal.

[0036] Furthermore, the central controller includes a protocol conversion unit for converting control signals from an external controller into the serial data stream. The control signals from the external controller include at least one of DMX512 signals, Art-Net signals, sACN signals, or TTL level serial port signals.

[0037] Furthermore, the serial data stream includes pixel-by-pixel real-time luminance data frames.

[0038] Furthermore, the first communication network is a differential serial communication bus network based on the RS485 or RS422 standard; or, the first communication network is a single-ended serial communication bus network based on the TTL, LVTTL, CMOS, LVCMOS, or RS232 standard.

[0039] Furthermore, the signal processing unit includes a microcontroller (MCU), which is also connected to a non-volatile memory for storing the device address of the local driving device.

[0040] Furthermore, the bus interface unit is configured to forward the data stream to the signal processing unit only when the destination address carried in the serial data stream matches the device address or the broadcast address.

[0041] Furthermore, the power line coupling unit includes a signal isolation transformer and a coupling capacitor for coupling the modulated signal to the AC or DC local power line.

[0042] Furthermore, the local drive device also includes a status monitoring unit for monitoring the electrical parameters of the local power line or the operating status of the LED string, and reporting it to the central controller through the bus interface unit and the first communication network.

[0043] This disclosure also reveals a power line carrier LED string control method based on hierarchical decoupling, including the following steps:

[0044] A serial data stream containing data for at least one LED string is generated by the central controller;

[0045] The serial data stream is distributed to multiple nodes via a first communication network operating based on a differential serial communication protocol or a single-ended serial communication protocol; in the local driving device at each node, the following steps are performed:

[0046] The serial data stream is received from the first communication network via a bus interface;

[0047] The received serial data stream is converted into a modulated signal suitable for transmission on power lines by a signal processing unit. In the conversion step, the signal processing unit does not parse the LED animation control data in the serial data stream, but directly performs protocol encapsulation or signal format conversion.

[0048] The modulated signal is injected into the local power line via a power line coupling unit; and...

[0049] The at least one LED string electrically connected to the local power line displays a corresponding LED animation effect in response to the modulation signal.

[0050] Furthermore, in the distribution step, the first communication network is a differential serial communication bus network based on the RS485 or RS422 standard; or, the first communication network is a single-ended serial communication bus network based on the TTL, LVTTL, CMOS, LVCMOS, or RS232 standard.

[0051] Furthermore, after the receiving step, the method further includes: determining whether the target address carried in the serial data stream matches the preset device address or broadcast address of the local driver, and performing subsequent conversion and injection steps only when a match is found.

[0052] Furthermore, it also includes the following steps: monitoring the working status of the LED string through the status monitoring unit of the local drive device; and reporting the working status to the central controller through the first communication network.

[0053] Furthermore, the pixel-by-pixel real-time brightness data frame is an RGB or RGBW data frame.

[0054] Compared with existing technologies using traditional single-layer coupled or flattened control architectures based on power line communication (PLC), the core inventive concept of this disclosure lies in its layered decoupling and non-analytical processing method. This enables the present disclosure to achieve the following significant benefits by constructing a layered decoupling architecture that combines serial data stream generation, high-speed bus transparent transmission, local MCU non-analytical protocol conversion, and power line communication PLC for short-distance (e.g., within one meter) driving:

[0055] This disclosure centralizes control intelligence entirely in a central controller, greatly simplifying the functions and hardware / software requirements of local drive devices. It reduces these devices to mere non-analyzable protocol converters, making them more than just non-analyzable protocol converters. Compared to existing single-layer coupled or flattened power line communication (PLC)-based control architectures, this disclosure constructs a layered, decoupled architecture: serial data stream generation + corresponding serial bus transparent transmission + local MCU non-analyzable protocol conversion + PLC power line communication for short-distance (e.g., within one meter) driving. This allows a single central controller to drive a large number of light strings, significantly reducing the number of main / sub-control devices and substantially lowering the overall system cost, while simplifying on-site construction and maintenance. Furthermore, this disclosure limits unstable power line communication to short-distance driving, such as the last meter, and through layered decoupling, fundamentally solves the low reliability and low speed problems of large-scale PLC transmission, as well as the incompatibility between existing PLC solutions and mainstream industry control protocols such as DMX512.

[0056] Furthermore, this disclosure employs a high-speed, interference-resistant differential serial bus (such as RS485 or RS422) as the backbone data distribution network, which significantly improves the communication rate and facilitates microsecond-level precise synchronization of large-scale LED light strings, ensuring the smoothness and consistency of complex dynamic animation effects. It should be noted that although the scheme based on the differential serial communication protocol has the additional advantage of long distance, it is costly for short-distance application scenarios. In this case, this disclosure further implements a first communication network based on a single-ended serial communication bus network using a single-ended serial protocol based on TTL, LVTTL, CMOS, LVCMOS, or RS232 standards. This reduces costs while also using the layered decoupling architecture disclosed in this disclosure to solve the problems of low reliability and low speed in large-scale PLC transmission, as well as the incompatibility between existing PLC solutions and mainstream industry control protocols such as DMX512.

[0057] In addition, the central controller can directly generate and distribute low-level, pixel-by-pixel real-time brightness data frames, rather than high-level instructions. This means that any complex LED animation effect can be generated and changed in real time at the central end without the need for firmware updates to a large number of local drive devices, greatly improving the system's flexibility and the efficiency of content updates.

[0058] Furthermore, this disclosure demonstrates that by supporting standard protocols such as DMX512 and providing protocol conversion interfaces, it can be compatible with a large number of existing lighting control devices and software, protecting user investment and improving system applicability;

[0059] Furthermore, this disclosure can also achieve remote monitoring and fault diagnosis of the working status of local light strings by introducing status monitoring and reporting functions, thereby upgrading the system from one-way control to two-way intelligent management and significantly enhancing the maintainability of the system. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of a power line carrier LED string control system based on hierarchical decoupling, as disclosed in one embodiment of this disclosure;

[0061] Figure 2 This is a schematic diagram of a power line carrier LED string control system based on hierarchical decoupling, as disclosed in another embodiment of this disclosure;

[0062] Figure 3 This is a flowchart illustrating a power line carrier LED string control method based on hierarchical decoupling, as disclosed in another embodiment of this disclosure. Detailed Implementation

[0063] To enable those skilled in the art to understand the technical solutions disclosed herein, the technical solutions of various embodiments will be described below in conjunction with the embodiments and related drawings. The described embodiments are only a part of the embodiments of this disclosure, not all of them. The reference to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments.

[0064] In one embodiment, this disclosure provides a power line carrier LED string control system and corresponding method based on hierarchical decoupling. See also Figure 1The system includes a central controller, a first communication network, multiple local drive units, and at least one LED string. The central controller generates a serial data stream containing LED animation control data; specifically, this serial data stream contains pixel-by-pixel real-time RGB or RGBW brightness data frames for at least one LED string. The first communication network, preferably a differential serial communication bus network based on RS485 or RS422 standards, is communicatively connected to the central controller and is used to distribute the serial data stream at high speed and reliably among multiple nodes. Multiple local drive units are connected to the first communication network as nodes and are each electrically connected to a local power line. The core function of each local drive unit is to decouple system functions in layers, including a bus interface unit, a signal processing unit, and a power line coupling unit. The bus interface unit receives the serial data stream from the first communication network. The signal processing unit, preferably a microcontroller (MCU), is configured not to parse the LED animation control data in the received serial data stream, but instead directly performs protocol encapsulation or signal format conversion to generate a modulated signal suitable for transmission on the power line. This non-analytical processing approach redefines the MCU's function as a lightweight protocol adapter and signal regenerator, greatly simplifying the hardware and software complexity of the local node. A power line coupling unit, preferably including a signal isolation transformer and coupling capacitors, is responsible for securely injecting the modulated signal into the local power line. For example, the power line coupling unit also includes a power line carrier modulation chip. At least one LED string is electrically connected to the local power line, displaying corresponding LED animation effects in response to the modulated signal on the line, thereby limiting the functionality of power line carrier technology to, for example, a simple electrical drive interface in the last meter.

[0065] It should be noted that although the differential serial communication protocol-based scheme has the additional advantage of long distance, it is costly for short-distance applications. In this case, this disclosure further implements a first communication network based on TTL, LVTTL, CMOS, LVCMOS, or RS232 standards through a single-ended serial protocol, thereby reducing costs. At the same time, it also uses the hierarchical decoupling architecture disclosed in this disclosure to solve the problems of low reliability and low speed in large-scale PLC transmission, as well as the incompatibility between existing PLC solutions and mainstream industry control protocols such as DMX512.

[0066] In the above embodiments, this disclosure centralizes control intelligence entirely in the central controller, greatly simplifying the functions and hardware / software requirements of the local drive device, making it merely a non-analytical protocol converter. Therefore, compared to existing technologies with traditional single-layer coupled or flattened power line communication (PLC)-based control architectures, this disclosure constructs a layered decoupled architecture: serial data stream generation + corresponding serial bus transparent transmission + local MCU non-analytical protocol conversion + power line communication PLC for short-distance (e.g., within one meter) driving. This allows a single central controller to drive a large number of light strings, significantly reducing the number of master / distributed control devices, substantially lowering the total system cost, and simplifying on-site construction and maintenance. This disclosure limits unstable power line communication to short-distance driving, such as the last meter, and solves the low reliability and low speed problems of large-scale PLC transmission, as well as the incompatibility between existing PLC solutions and mainstream industry control protocols such as DMX512, through layered decoupling.

[0067] Furthermore, existing technologies using traditional single-layer coupled or flattened power line communication (PLC)-based control architectures embed animation instructions for LED decorative lights in the firmware. The MCU drives the LED string based on these built-in animation instructions, and firmware updates require individual programmer connections. In contrast, this disclosure allows the central controller to directly generate and distribute low-level, pixel-by-pixel real-time brightness data frames, rather than high-level instructions. This means that any complex LED animation effect can be generated and modified in real time at the central end, eliminating the need for firmware updates to a large number of local drive devices, significantly improving system flexibility and the efficiency of content updates.

[0068] Preferably, in order to achieve control over a specific node, the local drive device further includes a non-volatile memory for storing device addresses, and the data is processed only when the destination address in the data stream matches the device address or is a broadcast address.

[0069] More preferably, the system can realize bidirectional communication, and the local drive device may include a status monitoring unit for monitoring the electrical parameters of the local power line or the working status of the LED string, and reporting to the central controller through the first communication network to realize remote monitoring and maintenance.

[0070] In another embodiment, the status monitoring unit includes at least one of a voltage sampling circuit, a current sampling circuit, and a temperature sensor.

[0071] In another embodiment, this disclosure discloses a power line carrier LED string control system based on hierarchical decoupling, comprising:

[0072] A central controller for generating a serial data stream containing data for at least one string of LEDs;

[0073] The first communication network operates based on a differential serial communication protocol or a single-ended serial communication protocol and is communicatively connected to the central controller for distributing the serial data stream among multiple nodes.

[0074] A plurality of local drive devices, each of which is communicatively connected to the first communication network and electrically connected to a local power line, and each of the local drive devices includes:

[0075] A bus interface unit is configured to receive the serial data stream from the first communication network;

[0076] The signal processing unit, which is communicatively connected to the bus interface unit, is configured not to parse the LED animation control data in the serial data stream, but to directly perform protocol encapsulation or signal format conversion to generate a modulated signal suitable for transmission on the power line.

[0077] A power line coupling unit, electrically connected to the signal processing unit and the local power line, is configured to inject the modulated signal into the local power line; and...

[0078] The at least one LED string is electrically connected to the local power line and is configured to display a corresponding LED animation effect in response to the modulation signal.

[0079] In another embodiment, the central controller includes a protocol conversion unit for converting control signals from an external controller into the serial data stream. The control signals from the external controller include at least one of DMX512 signals, Art-Net signals, sACN signals, or TTL-level serial port signals. Clearly, the central controller can easily integrate various standard protocols, concentrating the protocol conversion complexity at a single point, allowing the entire system to seamlessly integrate with existing workflows.

[0080] In another embodiment, the serial data stream includes pixel-by-pixel real-time luminance data frames.

[0081] In another embodiment, the first communication network is a differential serial communication bus network based on the RS485 or RS422 standard; or, the first communication network is a single-ended serial communication bus network based on the TTL, LVTTL, CMOS, LVCMOS, or RS232 standard.

[0082] As mentioned above, although the differential serial communication protocol-based scheme has the additional advantage of long distance, it is costly for short-distance applications. In this case, this disclosure further implements a first communication network based on a single-ended serial communication bus network of TTL, LVTTL, CMOS, LVCMOS, or RS232 standards through a single-ended serial protocol, thereby reducing costs. At the same time, it also uses the hierarchical decoupling architecture disclosed in this disclosure to solve the problems of low reliability and low speed of large-scale transmission of PLCs, as well as the incompatibility between existing PLC solutions and mainstream industry control protocols such as DMX512.

[0083] In another embodiment, the signal processing unit includes a microcontroller (MCU) and a non-volatile memory connected to it for storing the device address of the local drive device.

[0084] In another embodiment, the bus interface unit is configured to forward the data stream to the signal processing unit only if the destination address carried in the serial data stream matches the device address or the broadcast address.

[0085] In another embodiment, the power line coupling unit includes a signal isolation transformer and a coupling capacitor for coupling the modulated signal to an AC or DC local power line.

[0086] In another embodiment, the local drive device further includes a status monitoring unit for monitoring the electrical parameters of the local power line or the operating status of the LED string, and reporting the status to the central controller via the bus interface unit and the first communication network.

[0087] See Figure 3 In another embodiment, this disclosure also discloses a power line carrier LED string control method based on hierarchical decoupling, comprising the following steps:

[0088] A serial data stream containing data for at least one LED string is generated by the central controller;

[0089] The serial data stream is distributed to multiple nodes via a first communication network operating based on a differential serial communication protocol or a single-ended serial communication protocol; in the local driving device at each node, the following steps are performed:

[0090] The serial data stream is received from the first communication network via a bus interface;

[0091] The received serial data stream is converted into a modulated signal suitable for transmission on power lines by a signal processing unit. In the conversion step, the signal processing unit does not parse the LED animation control data in the serial data stream, but directly performs protocol encapsulation or signal format conversion.

[0092] The modulated signal is injected into the local power line via a power line coupling unit; and...

[0093] The at least one LED string electrically connected to the local power line displays a corresponding LED animation effect in response to the modulation signal.

[0094] In another embodiment, during the distribution step, the first communication network is a differential serial communication bus network based on the RS485 or RS422 standard; or, the first communication network is a single-ended serial communication bus network based on the TTL, LVTTL, CMOS, LVCMOS, or RS232 standard.

[0095] In another embodiment, after the receiving step, the method further includes: determining whether the target address carried in the serial data stream matches the device address preset by the local driver or the broadcast address, and performing subsequent conversion and injection steps only if a match is found.

[0096] In another embodiment, the method further includes the following steps: monitoring the operating status of the LED string through the status monitoring unit of the local drive device; and reporting the operating status to the central controller through the first communication network.

[0097] In another embodiment, the pixel-by-pixel real-time luminance data frame is an RGB or RGBW data frame.

[0098] See Figure 2 In one embodiment, this disclosure discloses a power line carrier LED string control system based on hierarchical decoupling, wherein,

[0099] The bus interface unit includes external signal circuit 1;

[0100] The signal processing unit includes MCU 2 and signal modulation circuit 4;

[0101] Power supply 3 provides power to MCU 2 and signal modulation circuit 4. MCU 2 outputs a dedicated power line carrier signal. MCU 2 can further control the modulation signals (e.g., modulation signals 4-1, 4-2, ..., 4-n) output by one or more parallel signal modulation circuits 4 to drive one or more LED decorative light strings (e.g., light strings 5-1, 5-2, ..., 5-n). Each LED light string includes an LED module for emitting light and a power line carrier chip connected to the LED module. The LED module includes one or more LED beads.

[0102] The external signal circuit 1 can output a TTL level signal. In this case, the MCU 2 is equivalent to the main control unit that uses or receives the TTL level signal. More preferably, the external signal circuit 1 can also output an RS485 or RS422 to TTL signal. In this case, in addition to the external signal circuit 1, an RS485-TTL converter or RS422-TTL converter is also involved. This converter bridges the microcontroller using the TTL level signal and the RS485 (or RS422) communication network.

[0103] MCU 2 generates a dedicated power line carrier signal based on the external signal, and drives the power line carrier LED 5 through the modulation signal output by the signal modulation circuit 4;

[0104] Thus, this embodiment can also achieve compatibility between power line carrier LED light strings and the original system without adding or changing the original control system, and implements a new three-layer hierarchical decoupling architecture, with each layer defined as follows:

[0105] The industrial command distribution layer, whose core is a differential serial communication bus network such as RS485 or RS422, is dedicated to high-speed, synchronous, and reliable multi-point long-distance communication, and undertakes the central function that power line carrier cannot originally perform.

[0106] The protocol conversion and driver layer, whose core is, for example, an MCU, is used to get rid of the existing technology of using MCUs that drive LED strings based on animation instructions built into the firmware to drive LED strings. The key to this disclosure is to convert the MCU’s function into a lightweight protocol adapter and signal regenerator and redefine the MCU.

[0107] The local electrical interface layer, whose core is based on power line carrier, has its function redefined as a simple electrical drive interface for the last distance, such as the last meter. It is only responsible for transmitting modulated data streams over extremely short distances, completely relieving the burden of long-distance reliable communication.

[0108] Therefore, this disclosure enables reliable transmission of large-scale, high-speed signals. By utilizing a first communication network based on differential serial communication protocol or single-ended serial communication protocol, the high-speed serial signal is ultimately converted into one or more low-speed power line carrier signals. This significantly reduces the number of main controllers and sub-controllers in the power line carrier LED string control system, as well as the difficulty of on-site construction.

[0109] Generally speaking, the transmission distance of schemes based on single-ended serial communication protocols is limited. Therefore, in another embodiment,

[0110] The system also includes a signal enhancement unit, which is used to improve signal driving capability, adapt to different level standards, or extend the effective communication distance.

[0111] Therefore, this embodiment proposes an enhancement scheme for a single-ended serial communication bus network.

[0112] In another embodiment,

[0113] The signal enhancement unit includes a bus driver, which is located at the signal output terminal of the central controller and is used to enhance the driving capability of the serial data stream to drive more capacitive loads or longer transmission lines.

[0114] In another embodiment,

[0115] The signal enhancement unit includes a level converter, which is used to perform level conversion on the serial data stream when there are segments or nodes with different operating voltages in the first communication network, so as to achieve logic level compatibility.

[0116] In another embodiment,

[0117] The signal enhancement unit includes at least one repeater, the input and output of which are respectively connected to different segments of the first communication network. The repeater is configured to receive the serial data stream, regenerate its signal, and retransmit it to extend the effective communication distance of the first communication network.

[0118] In another embodiment,

[0119] The repeater is integrated in at least one of the local driving devices; the signal processing unit of the local driving device is further configured to: after completing the reception and address determination of the serial data stream, re-drive the serial data stream or the data stream forwarded by it and output it to the subsequent segment of the first communication network.

[0120] In another embodiment,

[0121] The signal enhancement unit includes a signal conditioning circuit configured to perform waveform shaping, filtering, or impedance matching on the serial data stream to suppress signal ringing, overshoot, or attenuation.

[0122] In another embodiment,

[0123] The signal enhancement unit is a modular functional unit independent of the central controller and the local drive device, and it is connected to the first communication network through a standard interface.

[0124] In another embodiment,

[0125] The function of the signal enhancement unit is implemented by a dedicated hardware circuit or programmable logic device integrated within the central controller.

[0126] Here are more specific examples and descriptions:

[0127] Example 1:

[0128] This embodiment details the basic architecture and working principle of the system disclosed herein, which embodies the core concept of centralized dynamic control. The system includes an industrial PC acting as a central controller, a first communication network based on an RS485 or RS422 bus, 100 local drive devices, and 100 LED strings. Dedicated lighting control software (such as Madrix) runs on the industrial PC. The operator edits or loads a complex LED animation sequence. The software generates pixel-by-pixel RGBW data covering all LED strings in real time at a frame rate of 30fps, for example, 4 bytes per pixel.

[0129] For example, this data is encapsulated into a custom protocol frame with the following format:

[0130] [Frame header 0xAA55][Destination address][Frame length][Data payload][CRC16 checksum].

[0131] For global animations, the target address is set to the broadcast address 0xFF.

[0132] Regarding the first communication network, this embodiment uses CAT5e twisted-pair cable to construct a 1000-meter-long RS485 or RS422 bus, with 120Ω resistors connected to both ends of the bus. The communication baud rate is set to 2.5Mbps, using the 8N1 data format. As for the physical topology of the first communication network, an appropriate physical topology can be selected from bus, star, or ring topologies.

[0133] For locally driven devices, the core of each device is an STM32F030F4P6 microcontroller (MCU), whose firmware code is extremely simple. After the device powers on, it reads its unique device address from the built-in EEPROM (e.g., set via a DIP switch, or configured via software commands from the central controller and stored in the MCU's internal EEPROM or Flash). Its workflow is as follows:

[0134] Receiving: The MCU's UART interface continuously listens to the RS485 or RS422 bus through the MAX485 transceiver chip.

[0135] Address filtering: Upon receiving a complete data frame with a correct CRC checksum, the MCU compares the destination address in the frame. If the address is the broadcast address 0xFF or matches the local address, the frame is processed; otherwise, it is discarded.

[0136] Non-analytical conversion and forwarding: The MCU does not parse the RGBW content in the data payload, that is, it does not perform any animation logic calculations. It directly sends the raw data payload (raw_data) to an external FSK (Frequency Shift Keying) power line carrier modulation chip via its SPI interface at a rate of 9600bps.

[0137] Coupling injection: The modulation signal generated by the power line carrier modulation chip is injected into the local power line that supplies DC power to the LED string connected to the device, through a small isolation transformer and coupling capacitor.

[0138] Each LED string (such as the WS2812B type) has a built-in power line carrier demodulation chip that demodulates the data signal from the power line and drives the LED beads to display the corresponding color and brightness. Since the power line carrier only transmits between the local driver and the LED string (distance less than 5 meters), the signal quality is high, and there are no long-distance attenuation or noise problems.

[0139] For example, taking RS485 as an example, the core logic of the MCU firmware in this embodiment is shown in the following pseudocode, which reflects its essence as a transparent data channel:

[0140] void new_mcu_controller(void) {

[0141] / / 1. Receive real-time animation data from RS485

[0142] if(rs485_receive_complete()) {

[0143] FrameData frame = parse_rs485_data();

[0144] / / 2. Check address

[0145] if(frame.address == 0xFF || frame.address == MY_ADDRESS) {

[0146] / / 3. Directly forward the data payload to the power line carrier chip

[0147] send_to_powerline(frame.raw_data, frame.length);

[0148] }

[0149] }

[0150] }

[0151] It is understood that, through this embodiment, the present disclosure achieves precise synchronous control of long-distance, large-scale LED light strings. Compared with existing technologies using traditional single-layer coupled or flattened control architectures based on power line communication (PLC), the present disclosure eliminates the need for independent programming and animation fixation for each device, reduces the number of sub-controllers, greatly simplifies production, installation, and maintenance, and achieves higher system synchronization accuracy and significantly reduced latency.

[0152] Example 2:

[0153] This embodiment, based on the system architecture of Embodiment 1, adds status monitoring and bidirectional communication functions, improving system maintainability. The basic system components and data downlink flow are the same as in Embodiment 1; the difference lies in the hardware and software design of the local driver device.

[0154] In terms of hardware, this embodiment adds a status monitoring unit to the PCB of the local driver device. This unit includes a resistor divider connected to the first ADC channel of the MCU for monitoring the input voltage.

[0155] A sampling resistor connected in series in the power supply path of the LED string has its voltage amplified by an operational amplifier and then fed into the second ADC channel of the MCU to monitor the operating current of the LED string; an NTC thermistor mounted close to the MCU is connected to the third ADC channel of the MCU to monitor the operating temperature of the MCU.

[0156] On the software side, a timed task has been added to the MCU firmware, which executes the following steps every 5 seconds:

[0157] Read the values ​​of each of the above ADC channels and convert them into actual voltage (V), current (A) and temperature (°C).

[0158] Check if the values ​​are within the preset safety range, such as voltage 23-25V, current <2A, and temperature <70℃;

[0159] The monitoring data and status flags are encapsulated into a status reporting data frame; the status flags can be represented by different flag bits, such as 0 or 1, for normal or abnormal conditions.

[0160] The status frame is sent back to the central controller via the first communication network; the central controller receives and displays the corresponding operating status, and can issue an alarm when there is an abnormality.

[0161] Therefore, this embodiment upgrades the system from a one-way control system to a two-way monitoring system, thereby enabling real-time health status monitoring of each remote light string driver. This allows for timely detection and location of problems in the early stages of a fault (such as overcurrent or overvoltage), thus improving operation and maintenance.

[0162] Example 3:

[0163] This embodiment demonstrates two variants that further optimize cost and reliability.

[0164] Option 1: Direct modulation by MCU

[0165] To further reduce hardware costs, this solution eliminates the dedicated power line carrier modulation chip. The signal processing unit directly implements the modulation function using an STM32F030 MCU. One of the MCU's GPIO pins is connected to the base of an NPN transistor (2N3904) via a 1kΩ current-limiting resistor. The transistor's collector is connected to the primary winding of a small magnetic ring isolation transformer, while the emitter is grounded. The transformer's secondary winding is connected to the local power line via a 0.1uF coupling capacitor. The MCU's firmware directly generates FSK signals (e.g., using 125kHz to represent data '1' and 135kHz to represent data '0') by precisely controlling the toggling frequency of the GPIO pin. This solution software-based modulation reduces hardware costs to almost zero.

[0166] Option 2: Ring network topology

[0167] To improve the reliability of long-distance communication, the first communication network adopts a ring topology. The central controller forms a physical loop through ring A and ring B, for example, by leading out two independent RS485 buses to realize ring A and ring B. Each local drive device is equipped with two corresponding communication interfaces (e.g., RS485 interfaces) to connect to ring A and ring B respectively. The central controller simultaneously transmits the same data on ring A and ring B. The MCU of the local drive device listens to both interfaces simultaneously and adopts a first-packet locking strategy: that is, it uses the first received and correctly verified data packet and ignores the same data packet received on the other interface within a short period of time. When a disconnection occurs at any point in the loop, the data can still reach all nodes in the other direction, realizing link redundancy. Obviously, the second scheme ensures that the system is unaffected by a single point of failure on the bus, and the system availability is close to 100%.

[0168] Example 4:

[0169] This embodiment demonstrates the compatibility of this disclosure with the DMX512 protocol. The central controller is a standard DMX512 console, whose output is a data stream conforming to the DMX512-A standard (based on the RS485 physical layer). This data stream is directly connected to the first communication network. The MCU firmware of the local driver device is configured to DMX512 protocol parsing mode.

[0170] Each local driver device is configured via a DIP switch or by a command issued by the central controller, and the configuration is stored in the MCU's internal EEPROM or Flash memory, setting a DMX512 start address (e.g., device 1 is set to 1, device 2 to 301). The MCU continuously listens for DMX512 data frames on the bus. Upon detecting a valid DMX512 start code (e.g., 0x00 representing standard dimming data), the MCU begins receiving data from 512 channels. Then, based on its own set start address, the MCU extracts the data for the consecutive channels assigned to it from these 512 channels. For example, if an LED string has 100 RGB LEDs (requiring 300 channels) and the start address of the local driver device is set to 1, the MCU extracts data from channels 1 to 300. Next, the MCU simulates the corresponding single-line return-to-zero (RZ) digital waveform using its GPIO pins, following the GRB sequence and specific timing required by the WS2812B chip, from these 300 bytes of data (each byte representing the brightness of a color channel). Finally, this digital waveform is sent to the power line coupling unit for modulation and injection. In this way, a standard DMX512 controller can directly control the LED light string of this system, and each local driver is equivalent to a DMX512 to power line carrier gateway.

[0171] It is understood that the first communication network is not limited to the RS485 standard, but can also be a differential serial communication bus network based on the DMX512 physical layer standard or the CAN bus standard; or, the first communication network can be a single-ended serial communication bus network based on the TTL, LVTTL, CMOS, LVCMOS, or RS232 standards. By defining an open and flexible communication protocol and setting a protocol conversion interface, this disclosure can seamlessly support DMX512, extended DMX512, TTL signals, and mainstream controllers on the market.

[0172] Preferably, the serial data stream conforms to at least one of the following: DMX512 protocol format, Art-Net protocol format, sACN protocol format, or a custom binary protocol format.

[0173] Example 5:

[0174] This embodiment demonstrates the compatibility of this disclosure with TTL level serial signals. Some simple controllers (such as Arduino and Raspberry Pi) output TTL level serial data via the TX pin of their UART. To integrate them into this system, a simple TTL-to-RS485 adapter module can be designed. This module includes a chip such as the MAX485, which converts the TTL signal into a differential signal before connecting it to the first communication network. Simultaneously, a simple serial protocol is agreed upon, for example: each frame of data begins with 0xFE, 0xEF, followed by a 1-byte address, a 2-byte length, an N-byte data payload, and a 2-byte CRC. The MCU is configured to parse this protocol. In this way, users can use low-cost, easily programmable platforms such as Arduino as a central controller to generate custom animation data and control this system.

[0175] Example 6:

[0176] Several specific methods by which the MCU in the signal processing unit converts the received serial data stream into a power line carrier modulated signal:

[0177] Straight-through forwarding: After the MCU receives a complete data packet (e.g., a custom protocol packet) via UART and passes address matching and verification, it directly sends the valid part of the entire data packet to an external dedicated power line carrier signal modulation circuit (e.g., an adjustment chip) in the same byte stream format via another UART or SPI interface. The signal modulation circuit is responsible for completing all modulation operations.

[0178] Timing Conversion: The MCU may receive compressed or non-directly driven data (such as brightness values ​​from DMX512); the MCU needs to translate this data into the strict timing waveform required by the target LED string chip (such as WS2812B); the MCU can generate this waveform by precisely controlling the duration of the high and low levels of a GPIO pin (such as code 0: 0.4us high + 0.85us low; code 1: 0.8us high + 0.45us low); the generated digital waveform is then sent to the power line carrier modulation unit;

[0179] Protocol encapsulation: The data received by the MCU needs to be repackaged into the data frame format specified by the power line carrier modulation chip; for example, some power line carrier chips require a preamble and synchronization word to be added before each data packet; the MCU will automatically add this header information before sending the valid data to the modulation chip;

[0180] In summary, regardless of the approach used, it can be observed that the core role of the MCU is that of a protocol / format converter, rather than an animation processor that executes animation instructions in the firmware as is the case in existing technologies.

[0181] Example 7:

[0182] In this disclosure, the scheme based on the single-ended serial communication protocol can be based on the TTL standard or the CMOS standard. For example, in this embodiment...

[0183] The first communication network is a bus network operating on a single-ended serial communication protocol based on the CMOS standard. The central controller can be a Raspberry Pi running lighting control software. The Raspberry Pi's Universal Asynchronous Receiver / Transmitter (UART) directly outputs serial data at 3.3V CMOS level or 3.3V TTL level on its TX pin. The first communication network consists of a bus formed by a three-core cable (signal line, power line, and ground line), with the signal line connecting the data inputs of all nodes. The network adopts a bus topology. To ensure signal integrity, at high speeds or over long distances (e.g., >1 meter), a small resistor of several tens of ohms can be connected in series on the signal line to dampen ringing, and appropriate pull-up / pull-down resistors can be configured at the receiving end. In the local driver unit: the bus interface unit can be simplified to a level buffer (such as a 74HC125 tri-state buffer gate) or directly connected to the UART RX pin of the MCU. Its task is to receive the voltage signal on the single-ended signal line and convert it into a stable digital level that the MCU can recognize. The signal processing unit uses a low-cost MCU (such as an STM32F030), whose UART port is directly connected to the bus interface unit. Its firmware core logic is to receive data frames, perform address matching and verification, and then forward the valid data payload directly through SPI or GPIO without parsing the animation content. The power line coupling unit modulates the signal output by the MCU and injects it into the local power line.

[0184] For this embodiment, the hierarchical decoupling architecture disclosed herein is fully applicable to simpler, lower-cost single-ended serial buses. Since the backbone network distance may be short (e.g., on a booth or a small building facade), this solution based on a single-ended serial communication protocol is sufficient to meet reliability requirements while further reducing costs.

[0185] Example 8:

[0186] This disclosure also discloses a scheme based on a single-ended serial communication protocol, wherein,

[0187] The central controller uses an inexpensive development board such as an Arduino, whose serial port's TX pin outputs a standard 5VTTL level signal. The first communication network is constructed via a simple three-wire bus: 5V VCC, GND, and DATA, where the DATA line is connected to the TX pin of the Arduino development board. In multiple local driver devices, the data input lines of all bus interface units are connected in parallel to the DATA line of the bus, and each MCU is assigned a unique address via software. The program running on the Arduino development board generates complete animation data for all LED strings and encapsulates it into a custom protocol frame, such as: [header 0xAA][destination address][data length][payload][CRC].

[0188] When all LED strings need to be controlled, the Arduino development board sends a data frame with a target address of broadcast address (such as 0xFF). All nodes receive this broadcast frame simultaneously. After their respective MCUs verify the data, they synchronously convert and send the payload data in the frame, i.e. the original LED driver data stream, to their respective power line carrier modules. All LED strings can then update the screen synchronously.

[0189] It can be observed that the single-ended serial communication protocol-based solution disclosed in this embodiment can achieve synchronous and centralized control of dozens or even hundreds of independent LED strings using only one TTL output pin of the Arduino development board. This is of great significance in actual production and assembly: existing technologies require a separate controller for each LED string and individual programming; while this implementation only requires an inexpensive development board and multiple standardized nodes. The single-ended serial communication bus network based on the TTL standard can significantly reduce material costs, programming complexity, and configuration time. Ultimately, through single-wire transmission at TTL levels, the output channels can be expanded. One TTL output port of the main controller can be expanded to multiple power line carrier outputs, thereby significantly improving the efficiency of the production process and reducing costs.

[0190] Example 9:

[0191] Generally, the transmission distance of schemes based on single-ended serial communication protocols is limited. This embodiment proposes an enhancement scheme for a single-ended serial communication bus network. Therefore, this embodiment discloses a power line carrier LED string control system based on hierarchical decoupling, which includes the aforementioned signal enhancement unit. The signal enhancement unit specifically includes:

[0192] At the output of the central controller, a bus driver chip such as 74HC244 is used to enhance the driving capability of the TTL signal in order to handle more capacitive loads.

[0193] If there are nodes with mixed voltages on the bus, for example, a Raspberry Pi with 3.3V as the master, but some node MCUs operate at 5V, a bidirectional level shifter can be added in the appropriate place;

[0194] For ultra-long distances, an active relay node can be set up. This relay node is also a local driving device. However, after its signal processing unit receives the data and completes the address judgment, in addition to driving the local light string, it will also re-drive the complete digital signal frame and send it to the next segment of the bus, thereby extending the communication distance.

[0195] The above-described embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, 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. Such 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 disclosure.

Claims

1. A method for controlling LED light strings based on hierarchical decoupling power line carrier, comprising the following steps: A serial data stream containing data for at least one LED string is generated by the central controller; The serial data stream is distributed to multiple nodes through a first communication network operating based on a differential serial communication protocol or a single-ended serial communication protocol; In the local drive unit at each node, the following steps are performed: The serial data stream is received from the first communication network via a bus interface; The received serial data stream is converted into a modulated signal suitable for transmission on power lines by a signal processing unit. In the conversion step, the signal processing unit does not parse the LED animation control data in the serial data stream, but directly performs protocol encapsulation or signal format conversion. The modulated signal is injected into the local power line via a power line coupling unit; as well as, The at least one LED string electrically connected to the local power line displays a corresponding LED animation effect in response to the modulation signal.

2. The method according to claim 1, wherein, Preferably, in the distribution step, the first communication network is a differential serial communication bus network based on the RS485 or RS422 standard; or, the first communication network is a single-ended serial communication bus network based on the TTL, LVTTL, CMOS, LVCMOS, or RS232 standard.

3. The method according to claim 1, wherein, After the receiving step, the method further includes: determining whether the target address carried in the serial data stream matches the preset device address or broadcast address of the local driver, and performing subsequent conversion and injection steps only when a match is found.

4. The method according to claim 1, wherein, It also includes the following steps: The status monitoring unit of the local drive device monitors the working status of the LED string and reports the working status to the central controller via the first communication network.

5. The method according to claim 1, wherein, The pixel-by-pixel real-time brightness data frame is an RGB or RGBW data frame.

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