SPI Light Strip Dimming With Time-Slot Control for Multi-Strip Links
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Solution Overview
Problem
Existing dimming control methods for LED light strips are costly due to the need for a single-chip microcomputer to ensure timing accuracy, and the SPI interface is limited to controlling only one or two light strips, making it unsuitable for applications with more than ten LED strips.
Innovation Solution
A dimming control method that utilizes a main control chip with a serial peripheral interface to output serial signals to multiple light strip links in a time-division multiplexed manner, eliminating the need for additional microcontrollers and allowing connection to multiple light strips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an external single-chip microcomputer is used to output ws2811 signals, then timing stability is guaranteed, but production cost increases significantly
Solution Approach 1:
The patent extracts the timing control function from the external single-chip microcomputer and integrates it into the main control chip's SPI interface. The main control chip directly generates ws2811 protocol signals through its SPI interface, eliminating the need for external microcontrollers while maintaining timing stability through hardware-level signal generation.
Solution Approach 2:
The patent merges the functions of the main control chip and the external single-chip microcomputer into a single integrated solution. The SPI interface of the main control chip is enhanced to directly output ws2811 signals, combining data processing and signal generation functions in one chip, thereby reducing system complexity and cost.
2Ease of manufacture
If the SPI interface is used to control light strips, then cost is reduced, but the interface can only connect to one or two light strips, limiting application range
Solution Approach 1:
The patent segments the control architecture by introducing multiple SPI interfaces or using a daisy-chain configuration where the first light strip link acts as an extension. Each SPI interface can independently control a light strip link, and multiple interfaces work in parallel to control multiple light strips simultaneously, expanding the system's capacity from 1-2 strips to supporting large-scale applications with ten or more strips.
Solution Approach 2:
The patent enhances the SPI interface's versatility by enabling it to directly drive ws2811 control chips in light strip links. The interface is designed to handle multiple light strip connections through parallel SPI channels or cascaded configurations, making a single main control chip capable of controlling ten or more light strips without requiring additional external microcontrollers for each strip.
3Device complexity
If multiple light strip links are controlled through time-division multiplexing, then the number of required SPI interfaces is reduced, but signal transmission timing becomes more complex
Solution Approach 1:
The patent implements time-division multiplexing by periodically switching between different SPI interfaces or different data lines to control multiple light strip links. Each light strip link is assigned a specific time slot within a periodic cycle, allowing the main control chip to sequentially send ws2811 signals to multiple strips through a single or fewer SPI interfaces, reducing hardware requirements while maintaining reliable timing through structured periodic transmission.
Data Source
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AI summary
A dimming control method includes: receiving a dimming instruction, and determining a plurality of serial signals each corresponding to a respective one of a plurality of output ports in a serial peripheral interface according to the dimming instruction, a serial signal including a plurality of dimming signals arranged in a sequence; outputting each serial signal through a corresponding output port according to a different time slot, so as to send the serial signal to the multiple control chips connected in series in the light strip link electrically connected to the corresponding output port; and causing each control chip in the multiple control chips to respond to the dimming signal corresponding to the time slot of the control chip in the received serial signal, and to control a light-emitting element electrically connected to the control chip to change a light-emitting state.