LED driving data adaptive transmission method and LED driving circuit

Abstract

The application discloses an LED driving data adaptive transmission method and an LED driving circuit, and belongs to the technical field of LED driving. The LED driving circuit comprises n driving chips connected in cascade, and a first LED driving chip is connected with two input signals from a controller; each driving chip comprises an input port and two bidirectional ports, one bidirectional port of an i-th driving chip is connected with the input port of an (i-1)-th driving chip, and the other bidirectional port is connected with the input port of an (i+1)-th driving chip. The data receiving port and the forwarding port are adaptively determined according to the data amount received by each port, the driving data is received from the data receiving port and decoded, and the remaining driving data is forwarded from the forwarding port to a driving chip in a later stage. The scheme of the application can still work normally at a single breakpoint, the orientations of the driving chips and the LED lamps on a circuit board are unified, and the PCB design efficiency and the display uniformity of the LED lamps are improved.

Description

Technical Field

[0001] This invention relates to the field of LED driving technology, and in particular to an adaptive data transmission method and LED driving circuit for LED driving. Background Technology

[0002] With the continuous development of LED lighting display technology, LEDs have been widely accepted by users due to their low power consumption, long lifespan, convenient transportation, environmental friendliness, and rich colors.

[0003] Existing LED display circuit board solutions such as Figure 1 As shown, the diagram includes two circuit boards, A and B, which are physically connected but not electrically linked. Both boards have multi-stage cascaded LED driver chips (only one stage is schematically shown in the diagram), with multiple LEDs connected to each stage. VDD is the power supply, GND is the ground terminal, and each of the OUT1, OUT2, OUT3, and OUT4 pins is connected to an LED. Communication data for board A is input from the left, and for board B from the right. Driver chip communication data is generally input from the DIN terminal and output from the DOUT terminal. Therefore, the chips on board B must be oriented in reverse relative to those on board A, resulting in significant differences in layout and routing; the circuit board layout design cannot be reused. With the continuous development of LED display technology, the number of driver devices and LEDs on the circuit boards is increasing, leading to longer design times for both circuit boards.

[0004] Secondly, the LEDs in circuit boards A and B are facing opposite directions, resulting in a difference in the light emission angle and affecting display uniformity. Finally, the driver chip uses single-wire transmission; a failure in a single stage can cause subsequent circuits to malfunction.

[0005] Based on this, the present invention proposes a novel adaptive data transmission method and LED driver circuit for LED driving. Firstly, it facilitates circuit board layout and routing, saving design time. Secondly, it provides data backup, ensuring that subsequent circuits continue to operate normally even if a single-stage LED driver circuit fails. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an adaptive transmission method for LED driving data and an LED driving circuit, in view of the above-mentioned defects of the prior art.

[0007] To achieve the above objectives, the present invention provides an adaptive transmission method for LED driving data, used in an LED driving circuit comprising n cascaded driving chips. Each driving chip includes one input port and two bidirectional ports. One bidirectional port of the i-th driving chip is connected to the input port of the (i-1)-th driving chip, and the other bidirectional port is connected to the input port of the (i+1)-th driving chip. The input port of the first LED driving chip is connected to the first output port of the controller, and the bidirectional port is connected to the second output port of the controller. i is a positive integer greater than or equal to 1 and less than or equal to n. The method includes the following steps: Step S1: The first output port of the controller continuously sends n sets of display data in each data frame, and the length of each set of display data is m bits; the second output port sends an additional set of dummy data with a length of m bits at the frame header of each data frame, and then sends the same display data synchronously with the first output port. Step S2: Each level of driver chip extracts the driver data corresponding to the current driver chip from the received data frame and forwards the remaining driver data to the subsequent driver chip. Step S2 includes: Step S21: Determine the data receiving port; Step S22: Determine the forwarding port based on the amount of data received by the bidirectional port; Step S23: Receive the driving data corresponding to the current driving chip from the data receiving port, decode it and drive the LED beads, and forward the remaining driving data to the subsequent driving chip from the forwarding port.

[0008] In the LED driving data adaptive transmission method of the present invention, the specific method of step S21 is as follows: After power-on, the input port is determined as the receiving port for the first frame of data. At the end time of each frame of data reception, the receiving port for the next frame of data is determined.

[0009] In the LED driving data adaptive transmission method of the present invention, the method for determining the receiving port of the next frame of data is as follows: When the amount of data received by the data receiving port of the current frame reaches a preset threshold, the receiving port of the next frame remains unchanged; otherwise, the receiving port of the next frame is determined to be another port whose received data amount has reached a preset threshold; the preset threshold is the data length of a set of display data.

[0010] In the LED driving data adaptive transmission method of the present invention, when determining the receiving port of the next frame of data as other ports whose received data amount reaches a preset threshold, if multiple ports reach the preset threshold, the port whose received data amount reaches the preset threshold first is determined as the receiving port of the next frame of data.

[0011] In the LED driving data adaptive transmission method of the present invention, when determining the receiving port of the next frame data as a port where the amount of received data has reached a preset threshold, when none of the ports have reached the preset threshold, the receiving port of the current frame data is used as the receiving port of the next frame data.

[0012] In the LED driving data adaptive transmission method of the present invention, if the data receiving port of the current frame is an input port, and there is a bidirectional port whose received data amount reaches a preset threshold at the same time, then the bidirectional port that reaches the preset threshold first is determined as the receiving port of the next frame data.

[0013] In the LED driving data adaptive transmission method of the present invention, the specific method of step S22 is as follows: Determine whether the amount of received data at each bidirectional port has reached a preset threshold before the current driver chip's driver data has been extracted; if so, determine that the bidirectional port is receiving normal input data and maintain the input state; if not, determine that the bidirectional port is a forwarding port and switch to the output state.

[0014] In the LED driving data adaptive transmission method of the present invention, in step S22, multiple bidirectional ports are allowed to be simultaneously determined as forwarding ports.

[0015] In the LED driving data adaptive transmission method of the present invention, in step S22, if the amount of data extracted by the current driving chip from the data receiving port does not reach a preset threshold, each bidirectional port maintains the input state and does not forward data.

[0016] The present invention also provides an LED driving circuit, which includes n cascaded driving chips. Each driving chip includes one input port and two bidirectional ports. One bidirectional port of the i-th driving chip is connected to the input port of the (i-1)-th driving chip, and the other bidirectional port is connected to the input port of the (i+1)-th driving chip. The input port of the first LED driving chip is connected to the first output port of the controller, and the bidirectional port is connected to the second output port of the controller. i is a positive integer greater than or equal to 1 and less than or equal to n. Each of the aforementioned driver chips further includes a port detection unit, a port control unit, a data processing unit, and a constant current drive unit; The port detection unit is configured to: count the amount of data received by each data port in the current frame, and send the results to the port control unit; The port control unit is configured to: switch the bidirectional port to input mode when each frame of data reception begins; determine the data receiving port and forwarding port according to the amount of data received by each port when each frame of data is received; and switch the bidirectional port designated as the forwarding port to output mode. The data processing unit is configured to: receive driving data, extract driving data of the current driving chip from it, reshape the remaining data to generate new driving data, and forward the new driving data from the forwarding port; The constant current driving unit is configured to drive LED beads for display based on the extracted driving data.

[0017] The present invention has the following beneficial effects: The LED driving circuit of the present invention includes n cascaded driving chips. The first LED driving chip receives two input signals from the controller. Each driving chip includes an input port and two bidirectional ports. One bidirectional port of the i-th driving chip is connected to the input port of the (i-1)-th driving chip, and the other bidirectional port is connected to the input port of the (i+1)-th driving chip. The data receiving port and the forwarding port are adaptively determined according to the amount of data received by each port. Driving data is received from the data receiving port and decoded, and the remaining driving data is forwarded to the subsequent driving chip from the forwarding port. The solution of the present invention can still work normally in the event of a single breakpoint, which improves the reliability of the LED circuit. The design and connection of the LED driving chip ports unify the orientation of the driving chips and LEDs on the circuit board, improving the PCB design efficiency and the display uniformity of the LEDs. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the layout of an LED lighting panel in the prior art.

[0019] Figures 2-3 This is a schematic diagram of an LED driving circuit provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the LED lighting panel layout provided in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram illustrating the steps of the LED driving data adaptive transmission method provided in an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram illustrating the specific processing flow of the LED driving data adaptive transmission method provided in an embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram of the controller data frame timing provided in an embodiment of the present invention.

[0024] Figure 8 The waveform diagram of the data frame of the driver chip #1 when the controller is connected from the left and there is no breakpoint.

[0025] Figure 9 The waveform diagram of the data frame of the driver chip #2 when the controller is connected from the left and there is no breakpoint.

[0026] Figure 10 The waveform diagram of the data frame of the driver chip #3 when the controller is connected from the left and there is no breakpoint.

[0027] Figure 11 The waveform diagram of the data frame of the driver chip #3 when the controller is connected from the right and there is no breakpoint.

[0028] Figure 12 The waveform diagram of the data frame of the driver chip #2 when the controller is connected from the right and there is no breakpoint.

[0029] Figure 13 The waveform diagram of the data frame of the driver chip #1 when the controller is connected from the right and there is no breakpoint.

[0030] Figure 14 This is a schematic diagram of the LED driving circuit when the controller is connected from the left and the driver chip #2 DIN is open.

[0031] Figure 15 The waveform of the first data frame of driver chip #2 when the controller is connected from the left and the DIN of driver chip #2 is open.

[0032] Figure 16 The waveform diagram of subsequent frame data of driver chip #2 when the controller is connected from the left and the DIN of driver chip #2 is open.

[0033] Figure 17 The waveform of the first data frame of driver chip #3 when the controller is connected from the left and driver chip #2 DIN is open.

[0034] Figure 18 The waveform diagram of the subsequent frame data of driver chip #3 when the controller is connected from the left and driver chip #2 DIN is open.

[0035] Figure 19 This is a schematic diagram of the LED driver circuit when the controller is connected from the right and the driver chip #2 DIN is open.

[0036] Figure 20 The waveform of the first data frame of driver chip #2 when the controller is connected from the right and the DIN of driver chip #2 is open.

[0037] Figure 21 The waveform diagram of the subsequent frame data of driver chip #2 when the controller is connected from the right and the DIN of driver chip #2 is open.

[0038] Figure 22The waveform of the first data frame of driver chip #1 when the controller is connected from the right and driver chip #2 DIN is open.

[0039] Figure 23 The waveform diagram of the subsequent frame data of driver chip #1 when the controller is connected from the right and driver chip #2 DIN is open.

[0040] Figure 24 The waveform of the data frame of driver chip #3 when the DIN of driver chip #2 is open and the controller is moved from the left to the right to send the first frame of data.

[0041] Figure 25 The waveform of the data frame of driver chip #3 when the DIN of driver chip #2 is open and the controller is moved from the left to the right to send subsequent frame data.

[0042] Figure 26 This is a schematic diagram of the LED driving circuit when the controller is connected from the left and the driver chip #2 DIO1 is open.

[0043] Figure 27 The waveform of the data frame of driver chip #2 when the controller is connected from the left and driver chip #2 DIO1 is open.

[0044] Figure 28 This is a schematic diagram of the internal structure of the driver chip. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. It should be understood that the embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0047] like Figure 2 , Figure 3 As shown in the figure, an embodiment of the present invention provides an LED driving circuit, which includes n cascaded driving chips. Figure 2 In the middle, the controller is connected from the left, corresponding to Figure 1 Layout of circuit board A Figure 3 In the middle, the controller is connected from the right, corresponding to Figure 1The layout of circuit board B is shown below. To distinguish them, the multiple LED driver chips are sequentially numbered #1, #2, #3…; each LED driver chip has the same function and pin structure. Each driver chip includes one input port DIN and two bidirectional ports DIO1 and DIO2. One bidirectional port of the i-th driver chip is connected to the input port DIN of the (i-1)-th driver chip, and the other bidirectional port is connected to the input port DIN of the (i+1)-th driver chip. The input port of the first LED driver chip is connected to the first output port data1 of the controller, and one bidirectional port is connected to the second output port data2 of the controller. Here, i is a positive integer greater than or equal to 2 and less than or equal to n.

[0048] Figure 2 and Figure 3 In this configuration, the pins of the control chip are oriented in the same direction. Figure 2 In the diagram, the bidirectional port DIO1 of the i-th driver chip is connected to the input port of the (i-1)-th driver chip, and the bidirectional port DIO2 is connected to the input port DIN of the (i+1)-th driver chip. Figure 3 In this diagram, the bidirectional port DIO2 of the i-th driver chip is connected to the input port of the (i-1)-th driver chip, and the bidirectional port DIO1 is connected to the input port DIN of the (i+1)-th driver chip. For example... Figure 4 For the corresponding PCB layout, the driver chip faces the same direction on both PCB A and PCB B. Therefore, PCB B can reuse the layout and routing of PCB A, requiring only modification to the routing of DATA1, DATA2, VCC, and GND, which can greatly save design time. In addition, the LEDs on PCB A and PCB B also face the same direction, with consistent light emission angles, significantly improving display uniformity.

[0049] Figure 5 This is a schematic diagram illustrating the steps of the LED driving data adaptive transmission method provided in an embodiment of the present invention. Figure 6 This is a schematic diagram illustrating the specific processing flow of the LED driving data adaptive transmission method provided in an embodiment of the present invention.

[0050] like Figure 5 , Figure 6 As shown, this embodiment of the invention also provides an adaptive transmission method for LED driving data, used in the aforementioned LED driving circuit; the method includes the following steps: Step S1: The first output port of the controller continuously sends n sets of display data in each data frame, and the length of each set of display data is m bits; the second output port sends an additional set of dummy data with a length of m bits at the frame header of each data frame, and then sends the same display data synchronously with the first output port. Step S2: Each level of driver chip extracts the driver data corresponding to the current driver chip from the received data frame and forwards the remaining driver data to the subsequent driver chip. Step S2 includes: Step S21: Determine the data receiving port.

[0051] Step S22: Determine the forwarding port based on the amount of data received by the bidirectional port.

[0052] Step S23: Receive the driving data corresponding to the current driving chip from the data receiving port, decode it and drive the LED beads, and forward the remaining driving data to the subsequent driving chip from the forwarding port.

[0053] like Figure 7 The diagram shows the timing of the data frames sent by the controller. The controller's first output port, data1, continuously sends multiple sets of display data, each set consisting of m bits. The number of sets equals the number of stages in the multi-stage drive current. The first set of display data belongs to driver chip #1, the second set belongs to driver chip #2, and so on. Compared to the first output port, data2 sends an additional m-bit dummy data set at the beginning of each data frame. This dummy data set is equal in length to one set of display data. Afterward, the first output port, data1, and the second output port, data2, synchronously send the same display data.

[0054] In this embodiment of the invention, the specific method of step S21 is as follows: After power-on, the input port is determined as the receiving port for the first frame of data. At the end time of each frame of data reception, the receiving port for the next frame of data is determined.

[0055] The method for determining the receiving port of the next frame of data is as follows: When the amount of data received by the data receiving port of the current frame reaches a preset threshold, the receiving port of the next frame remains unchanged; otherwise, the receiving port of the next frame is determined to be another port whose received data amount has reached the preset threshold; if multiple ports reach the preset threshold, the port whose received data amount reaches the preset threshold first is determined to be the receiving port of the next frame. The preset threshold is the data length of a set of display data, i.e., m bits.

[0056] Specifically, when none of the ports have reached the preset threshold, the data receiving port of the current frame will be used as the data receiving port of the next frame.

[0057] Specifically, if the data receiving port of the current frame is an input port, and there exists a bidirectional port whose received data volume reaches a preset threshold simultaneously, then the bidirectional port that reaches the preset threshold first is determined to be the receiving port for the next frame's data. This situation occurs if a bidirectional port of the driver chip is short-circuited with its own input port.

[0058] In this embodiment of the invention, the specific method of step S22 is as follows: The system determines whether the amount of data received by each bidirectional port reaches a preset threshold before extracting all the driver data from the current driver chip. If yes, the bidirectional port is considered to be receiving normal input data and remains in input mode. If not, the bidirectional port is identified as a forwarding port and switched to output mode. Note that multiple bidirectional ports can be identified as forwarding ports simultaneously. If the amount of data extracted by the current driver chip from the data receiving port does not reach the preset threshold, all bidirectional ports remain in input mode and do not forward data.

[0059] Under normal, uninterrupted conditions, one bidirectional port will have data input, while the other will not. If the bidirectional port closer to the controller is open-circuited or short-circuited to VDD or GND, neither bidirectional port will have data input. If the input port is short-circuited to the bidirectional port furthest from the controller, both bidirectional ports will have data input.

[0060] Figures 2-4 In the LED driver circuit shown, the single breakpoint conditions of the driver chip include: DIN, DIO1, and DIO2 open circuit; DIN, DIO1, and DIO2 short circuit to VDD; DIN, DIO1, and DIO2 short circuit to GND; and DIN short circuit to either DIO1 or DIO2. The LED driver data transmission method provided in this embodiment of the invention can transmit LED driver data normally in both the no-breakpoint and above breakpoint conditions. The processing strategies for different single-breakpoint conditions according to the LED driver data transmission method provided in this embodiment of the invention are described in the table below.

[0061] Table 1 Summary of processing strategies under different single breakpoint conditions

[0062] The following section uses a cascaded three-stage driver chip as an example to illustrate the driver data transmission methods under conditions of no breakpoints, open DIN circuits, and some special cases. The processing flow for other single-breakpoint scenarios can be deduced similarly.

[0063] (1) The controller is connected from the left and there is no breakpoint. like Figure 2 As shown, the controller is connected from the left, and the driver chip #1 is connected to the controller. The driver chip #2 and driver chip #3 are cascaded after the driver chip #1.

[0064] For driver chip #1, its data port waveform timing is as follows: Figure 8 As shown, the processing flow is as follows: (a) As described in step S21, DIN is set as the data receiving port by default upon power-on.

[0065] (b) According to step S22, compared with the time point when the data receiving port finishes extracting the display data of the local driver chip, the amount of input data of DIO1 reaches the preset threshold first, while the amount of input data of DIO2 does not reach the preset threshold. Therefore, DIO2 is determined to be a forwarding port and is switched to output state.

[0066] (c) Forward the remaining drive data from DIO2 as described in step S23.

[0067] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the current frame data receiving port DIN meets the preset threshold, and the next frame data receiving port is determined to be DIN.

[0068] The processing flow of subsequent driver chips can be deduced in the same way. The waveform timing of the data ports of driver chips #2 and #3 are as follows: Figure 9 , Figure 10 As shown.

[0069] (2) The controller is connected from the right side and there is no breakpoint. like Figure 3 As shown, the controller is connected from the right, and the driver chip #3 is connected to the controller. The driver chip #2 and driver chip #1 are cascaded after the driver chip #3.

[0070] For driver chip #3, its data port waveform timing is as follows: Figure 11 As shown, the processing flow is as follows: (a) As described in step S21, DIN is set as the data receiving port by default upon power-on.

[0071] (b) According to step S22, compared with the time when the data receiving port finishes extracting the display data of the local driver chip, the amount of input data of DIO2 reaches the preset threshold first, while the amount of input data of DIO1 does not reach the preset threshold. Therefore, DIO1 is determined to be a forwarding port and is switched to output state.

[0072] (c) According to step S23, forward the remaining drive data from DIO1.

[0073] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the current frame data receiving port DIN meets the preset threshold, and the next frame data receiving port is determined to be DIN.

[0074] The specific algorithm flow of subsequent driver chips can be deduced in the same way. The waveform timing of the data ports of driver chip #2 and driver chip #1 are as follows: Figure 12 , Figure 13 As shown.

[0075] (3) The controller is connected from the left side, with the DIN open circuit. like Figure 14 As shown, the controller is connected from the left, and the driver chip #1 is connected to the controller. Driver chip #2 and driver chip #3 are cascaded after driver chip #1. Assume that the input port DIN of driver chip #2 is open.

[0076] The processing flow of driver chip #1 is the same as that when there are no breakpoints.

[0077] When the first frame of driver data is sent, the waveform at the data port of driver chip #2 is as follows: Figure 15 As shown, the processing flow is as follows: (a) As described in step S21, DIN is set as the data receiving port by default upon power-on.

[0078] (b) As described in step S22, the data receiving port has failed to receive a set of display data, and DIO1 and DIO2 remain in the input state. There is no forwarding port for this frame, and no data is forwarded.

[0079] (c) After the controller finishes sending data, according to step S21, it is determined that the amount of data input to the frame data receiving port DIN does not meet the preset threshold, and only the amount of data input to DIO1 among DIO1 and DIO2 meets the preset threshold. The next frame data receiving port is then determined to be DIO1.

[0080] Starting from the transmission of the second frame of driver data, the waveforms of the data port of driver chip #2 in subsequent frames are as follows: Figure 16 As shown, the processing flow is as follows: (a) As described in step S21, when the frame data receiving port is DIO1, drive data is received from DIO1.

[0081] (b) As described in step S22, if the amount of input data to DIO2 has not reached the preset threshold compared to the time when the data receiving port has finished extracting the display data of the local driver chip, DIO2 is determined to be a forwarding port and switched to output mode. Specifically, when receiving data from DIO1 or DIO2, the first set of display data is identified as dummy data and discarded; the next set of display data is extracted as the actual display data of the local driver chip.

[0082] (c) Forward the remaining drive data from DIO2 as described in step S23.

[0083] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the frame data receiving port DIO1 meets the preset threshold, and the next frame data receiving port is determined to be DIO1.

[0084] When the first frame of driver data is sent, the waveform of the data port of driver chip #3 is as follows: Figure 17 As shown, the processing flow is as follows: (a) As described in step S21, DIN is set as the data receiving port by default upon power-on.

[0085] (b) As described in step S22, the data receiving port failed to receive a set of display data (because DIO2 of driver chip #2 does not forward data), and DIO1 and DIO2 remain in the input state. There is no forwarding port in this frame, and no data is forwarded.

[0086] (c) After the controller finishes sending data, according to step S21, it is determined that the amount of data input to the frame data receiving port DIN does not meet the preset threshold, and only the amount of data input to DIO1 among DIO1 and DIO2 meets the preset threshold. The next frame data receiving port is then determined to be DIO1.

[0087] Starting from the transmission of the second frame of drive data, the waveforms of the data port of driver chip #3 in subsequent frames are as follows: Figure 18 As shown, the processing flow is as follows: (a) As described in step S21, when the frame data receiving port is DIO1, drive data is received from DIO1.

[0088] (b) According to step S22, compared with the time point when the data receiving port finishes extracting the display data of the local driver chip, the amount of input data of DIO2 has not reached the preset threshold, so it is determined that DIO2 is a forwarding port and is switched to output state.

[0089] (c) As described in step S23, the remaining drive data should be forwarded from DIO2, but drive chip #3 is already at the end and there is no data to forward.

[0090] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the frame data receiving port DIO1 meets the preset threshold, and the next frame data receiving port is determined to be DIO1.

[0091] (4) The controller is connected from the right side, and the DIN circuit is open. like Figure 19 As shown, the controller is connected from the right, and the driver chip #3 is connected to the controller. The driver chip #2 and driver chip #1 are cascaded after the driver chip #3. Assume that the input port DIN of the driver chip #2 is open.

[0092] The specific process and data port waveform of the algorithm corresponding to #3 are consistent with those when there are no breakpoints.

[0093] When the first frame of driver data is sent, the waveform at the data port of driver chip #2 is as follows: Figure 20 As shown, the processing flow is as follows: (a) As described in step S21, DIN is set as the data receiving port by default upon power-on.

[0094] (b) As described in step S22, the data receiving port has failed to receive a set of display data, and DIO1 and DIO2 remain in the input state. There is no forwarding port for this frame, and no data is forwarded.

[0095] (c) After the controller finishes sending data, according to step S21, it is determined that the amount of data input to the frame data receiving port DIN does not meet the preset threshold, and only the amount of data input to DIO2 among DIO1 and DIO2 meets the preset threshold. The next frame data receiving port is then determined to be DIO2.

[0096] Starting from the transmission of the second frame of driver data, the waveforms of the data port of driver chip #2 in subsequent frames are as follows: Figure 21 As shown, the processing flow is as follows: (a) As described in step S21, when the frame data receiving port is DIO2, drive data is received from DIO2.

[0097] (b) According to step S22, compared with the time point when the data receiving port finishes extracting the data displayed by the local driver chip, the amount of input data of DIO1 has not reached the preset threshold, so it is determined that DIO1 is a forwarding port and is switched to output state.

[0098] (c) According to step S23, forward the remaining drive data from DIO1.

[0099] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the frame data receiving port DIO2 meets the preset threshold, and the next frame data receiving port is determined to be DIO2.

[0100] When the first frame of driver data is sent, the waveform at the data port of driver chip #1 is as follows: Figure 22 As shown, the processing flow is as follows: (a) As described in step S21, DIN is set as the data receiving port by default upon power-on.

[0101] (b) As described in step S22, the data receiving port failed to receive a set of display data (because DIO1 of driver chip #2 does not forward data), and DIO1 and DIO2 remain in the input state. There is no forwarding port in this frame, and no data is forwarded.

[0102] (c) After the data reception is completed, according to step S21, it is determined that the amount of data input to the current frame data receiving port DIN does not meet the preset threshold, and only the amount of data input to DIO2 among DIO1 and DIO2 meets the preset threshold. The next frame data receiving port is then determined to be DIO2.

[0103] Starting from the transmission of the second frame of drive data, the waveforms of the data port of driver chip #1 in subsequent frames are as follows: Figure 23 As shown, the processing flow is as follows: (a) As described in step S21, when the frame data receiving port is DIO2, drive data is received from DIO2.

[0104] (b) According to step S22, compared with the time point when the data receiving port finishes extracting the display data of the local driver chip, the amount of input data of DIO1 has not reached the preset threshold, so it is determined that DIO1 is a forwarding port and is switched to output state.

[0105] (c) As described in step S23, the remaining driver data should be forwarded from DIO1, but #1 is the last driver chip and there is no remaining data to be forwarded.

[0106] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the frame data receiving port DIO2 meets the preset threshold, and the next frame data receiving port is determined to be DIO2.

[0107] (5) When the amount of data received by the data receiving port of the current frame has not reached the preset threshold, the amount of data received by multiple other ports has reached the preset threshold. In some embodiments of the present invention, when the amount of data received by the data receiving port of the current frame reaches a preset threshold, the receiving port of the next frame remains unchanged; otherwise, the receiving port of the next frame is determined to be another port whose received data amount has reached the preset threshold; if multiple ports reach the preset threshold, the port whose received data amount reaches the preset threshold first is determined to be the receiving port of the next frame. Specific examples are as follows, assuming that according to... Figure 14 In this configuration, the controller connects from the left. After sending multiple frames of data, driver chip #1 selects DIN as the data receiving port, while driver chips #2 and #3 both select DIO1 as the data receiving port. Later, it is changed to... Figure 19 The connection method does not require a power cycle.

[0108] After the connection was changed, the first frame of data was sent. The waveform of the data port of driver chip #3 is as follows: Figure 24 As shown, the workflow is as follows: (a) As described in step S21, DIO1 has been selected as the data receiving port before the connection was changed.

[0109] (b) As described in step S22, the data receiving port has failed to receive a set of display data, and DIO1 and DIO2 remain in the input state. There is no forwarding port for this frame, and no data is forwarded.

[0110] (c) After data reception is completed, according to step S21, it is determined that the amount of input data at the current frame data receiving port DIO1 does not meet the preset threshold, while the amounts of input data at DIN and DIO2 both meet the preset threshold. DIO2 reaches the preset threshold before DIN, so the receiving port for the next frame data is determined to be DIO2.

[0111] Starting with the second frame of data sent after the connection was changed, the waveform of the data port of driver chip #3 is as follows: Figure 25 As shown, the workflow is as follows: (a) As described in step S21, when the frame data receiving port is DIO2, drive data is received from DIO2.

[0112] (b) According to step S22, compared with the time point when the data receiving port finishes extracting the data displayed by the local driver chip, the amount of input data of DIO1 has not reached the preset threshold, so it is determined that DIO1 is a forwarding port and is switched to output state.

[0113] (c) According to step S23, forward the remaining drive data from DIO1.

[0114] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the frame data receiving port DIO2 meets the preset threshold, and the next frame data receiving port is determined to be DIO2.

[0115] The waveforms of the data ports corresponding to driver chip #2 and driver chip #1 will not be described in detail.

[0116] (6) Multiple bidirectional ports were identified as forwarding ports. like Figure 26 As shown, the controller inputs data from the left, and the bidirectional port closest to the controller is DIO1. Assume that the DIO1 port of driver chip #2 is open.

[0117] The processing flow and data port waveforms of driver chip #1 and driver chip #3 are consistent with those when there are no breakpoints.

[0118] The waveform of the data port of driver chip #2 is as follows Figure 27 As shown, the processing flow is as follows: (a) As described in step S21, DIN is set as the data receiving port by default upon power-on.

[0119] (b) According to step S22, compared with the time point when the data receiving port finishes extracting the display data of the local driver chip, the amount of input data of DIO1 and DIO2 has not reached the preset threshold. It is determined that DIO1 and DIO2 are both forwarding ports and are switched to output state.

[0120] (c) As described in step S23, the remaining drive data is forwarded simultaneously from DIO1 and DIO2.

[0121] (d) After the data reception is completed, according to step S21, it is determined that the amount of data input to the current frame data receiving port DIN meets the preset threshold, and the next frame data receiving port is determined to be DIO1.

[0122] Figure 28 A schematic diagram of the internal structure of each driver chip. (Example) Figure 28 As shown, each of the aforementioned driver chips further includes the following units: (1) Port detection unit: counts the amount of data received by each data port in the current frame and sends the results to the port control unit.

[0123] (2) Port control unit: At the start of each frame of data reception, both bidirectional ports are switched to input mode. When receiving data for each frame, the data receiving port and forwarding port are determined according to the amount of data received by each port. The bidirectional port designated as the forwarding port is switched to output mode.

[0124] (3) Data processing unit: receives driving data, extracts the driving data of the current driving chip from it, reshapes the remaining data to generate new driving data, and forwards it from the forwarding port.

[0125] (4) Constant current drive unit: Drives LED beads to display based on the extracted drive data.

[0126] The interface control unit determines the receiving port in the following manner: After power-on, the input port is determined as the receiving port for the first frame of data. At the end time of each frame of data reception, the receiving port for the next frame of data is determined.

[0127] The method for determining the receiving port of the next frame of data is as follows: When the amount of data received by the data receiving port of the current frame reaches a preset threshold, the receiving port of the next frame remains unchanged; otherwise, the receiving port of the next frame is determined to be another port whose received data amount has reached the preset threshold; the preset threshold is the data length of a set of displayed data. If multiple ports reach the preset threshold, the port whose received data amount reaches the preset threshold first is determined to be the receiving port of the next frame. When none of the ports have reached the preset threshold, the data receiving port of the current frame is used as the receiving port of the next frame. If the data receiving port of the current frame is an input port, and there is a bidirectional port whose received data amount reaches the preset threshold at the same time as its input port, the bidirectional port that reaches the preset threshold first is determined to be the receiving port of the next frame.

[0128] The interface control unit determines the forwarding port in the following manner: The system determines whether the amount of data received by each bidirectional port reaches a preset threshold before extracting all the driver data from the current driver chip. If yes, the bidirectional port is considered to be receiving normal input data and remains in input mode. If not, the bidirectional port is identified as a forwarding port and switched to output mode. Multiple bidirectional ports are allowed to be identified as forwarding ports simultaneously. If the amount of data extracted by the current driver chip from the data receiving port does not reach the preset threshold, all bidirectional ports remain in input mode and do not forward data.

[0129] The above are merely specific embodiments of the present invention and should not be construed as limiting the scope of the present invention. Equivalent variations made by those skilled in the art based on this invention, as well as changes well-known to those skilled in the art, should still fall within the scope of the present invention.

Claims

1. An adaptive data transmission method for LED driving, used in an LED driving circuit comprising n cascaded driving chips, characterized in that, Each of the aforementioned driver chips includes one input port and two bidirectional ports. The input port of the first LED driver chip is connected to the first output port of the controller, one bidirectional port is connected to the second output port of the controller, and the other bidirectional port is connected to the input port of the adjacent next driver chip. One bidirectional port of the i-th driver chip is connected to the input port of the (i-1)-th driver chip, and the other bidirectional port is connected to the input port of the (i+1)-th driver chip, where i is a positive integer greater than or equal to 2 and less than n. One bidirectional port of the last LED driver chip is connected to the input port of the adjacent previous driver chip, and the other bidirectional port is left unused. The method includes the following steps: Step S1: The first output port of the controller continuously sends n sets of display data in each data frame, and the length of each set of display data is m bits; the second output port sends an additional set of dummy data with a length of m bits at the frame header of each data frame, and then sends the same display data synchronously with the first output port. Step S2: Each level of driver chip extracts the driver data corresponding to the current driver chip from the received data frame and forwards the remaining driver data to the subsequent driver chip. Step S2 includes: Step S21: Determine the data receiving port; Step S22: Determine the forwarding port based on the amount of data received by the bidirectional port; Step S23: Receive the driving data corresponding to the current driving chip from the data receiving port, decode it and drive the LED beads, and forward the remaining driving data to the subsequent driving chip from the forwarding port.

2. The LED driving data adaptive transmission method according to claim 1, characterized in that, The specific method for step S21 is as follows: After power-on, the input port is determined as the receiving port for the first frame of data. At the end time of each frame of data reception, the receiving port for the next frame of data is determined.

3. The LED driving data adaptive transmission method according to claim 2, characterized in that, The method for determining the receiving port of the next frame of data is as follows: When the amount of data received by the data receiving port of the current frame reaches a preset threshold, the data receiving port of the next frame remains unchanged. Otherwise, the receiving port for the next frame of data is determined to be another port where the amount of received data has reached a preset threshold; The preset threshold is the length of a set of displayed data.

4. The LED driving data adaptive transmission method according to claim 3, characterized in that, When determining the receiving port of the next frame of data as another port whose received data amount has reached a preset threshold, if multiple ports have reached the preset threshold, then the port whose received data amount first reaches the preset threshold is determined as the receiving port of the next frame of data.

5. The LED driving data adaptive transmission method according to claim 3, characterized in that, When determining the receiving port of the next frame data as another port whose received data volume has reached a preset threshold, if none of the ports have reached the preset threshold, the receiving port of the current frame data will be used as the receiving port of the next frame data.

6. The LED driving data adaptive transmission method according to claim 3, characterized in that, If the data receiving port of the current frame is an input port, and there is a bidirectional port whose received data volume reaches the preset threshold at the same time, then the bidirectional port that reaches the preset threshold first is determined as the receiving port of the next frame.

7. The LED driving data adaptive transmission method according to claim 1, characterized in that, The specific method for step S22 is as follows: Determine whether the amount of received data at each bidirectional port has reached a preset threshold before the current driver chip's driver data has been extracted; if so, determine that the bidirectional port is receiving normal input data and maintain the input state; if not, determine that the bidirectional port is a forwarding port and switch to the output state.

8. The LED driving data adaptive transmission method according to claim 7, characterized in that, In step S22, multiple bidirectional ports are allowed to be identified as forwarding ports simultaneously.

9. The LED driving data adaptive transmission method according to claim 7, characterized in that, In step S22, if the amount of data extracted by the current driver chip from the data receiving port does not reach the preset threshold, each bidirectional port maintains the input state and does not forward data.

10. An LED driving circuit, characterized in that, The LED driving circuit includes n cascaded driving chips. Each driving chip includes one input port and two bidirectional ports. The input port of the first LED driving chip is connected to the first output port of the controller, one bidirectional port is connected to the second output port of the controller, and the other bidirectional port is connected to the input port of the adjacent next driving chip. One bidirectional port of the i-th driving chip is connected to the input port of the (i-1)-th driving chip, and the other bidirectional port is connected to the input port of the (i+1)-th driving chip, where i is a positive integer greater than or equal to 2 and less than n. One bidirectional port of the last LED driving chip is connected to the input port of the adjacent previous driving chip, and the other bidirectional port is left unused. Each of the aforementioned driver chips further includes a port detection unit, a port control unit, a data processing unit, and a constant current drive unit; The port detection unit is configured to: count the amount of data received by each data port in the current frame, and send the results to the port control unit; The port control unit is configured to: switch the bidirectional port to input mode when each frame of data reception begins; determine the data receiving port and forwarding port according to the amount of data received by each port when each frame of data is received; and switch the bidirectional port designated as the forwarding port to output mode. The data processing unit is configured to: receive driving data, extract driving data of the current driving chip from it, shape the remaining data to generate new driving data, and forward the new driving data from the forwarding port; The constant current driving unit is configured to drive LED beads for display based on the extracted driving data.

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