Edge-Based PWM Communication Timers for Collision-Free Slave Response
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Solution Overview
Problem
Conventional SPC protocol-based communication systems require long trigger pulse durations and complex receive hardware, leading to inefficient data transmission and potential collisions between slave devices in automotive applications.
Innovation Solution
Implementing a bidirectional edge-based pulse width modulation protocol with timers in slave devices that elapse after receiving a master trigger signal, allowing each slave device to transmit data consecutively with varying time periods to avoid collisions and reduce overall transmission time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional SPC protocol with trigger pulses is used for bidirectional communication, then communication between master and slave devices is enabled, but the transmission time becomes comparatively long (about 90 time units for addressing plus at least 281 time units for responding)
Solution Approach 1:
Slave devices are pre-configured with unique timer values before communication begins. When a master trigger signal is received, each slave device's timer starts immediately and elapses after its predetermined time period, enabling consecutive transmissions without waiting for trigger pulse completion or listening for bus idle states. This preliminary configuration eliminates the need for sequential triggering and reduces overall communication time.
2Reliability
If slave devices listen to the bus continuously to detect transmissions and termination, then collision avoidance is achieved, but receive hardware and logic complexity increases
Solution Approach 1:
Each slave device is pre-assigned a unique timer value during system initialization or device configuration. When the master sends a trigger signal, all slave devices start their timers simultaneously, but each timer elapses at a different predetermined time. This ensures that only one slave device transmits at a time without requiring continuous bus monitoring or complex collision detection logic, thereby maintaining reliability while simplifying hardware.
3Adaptability or versatility
If trigger pulse duration is extended to accommodate all slave devices, then all slaves can be addressed, but the overall transmission time increases
Solution Approach 1:
The addressing function is segmented from the transmission timing function. Instead of using a single long trigger pulse to address multiple slaves sequentially, the system uses a short trigger pulse that simultaneously starts timers in all slave devices. Each slave device has its own unique timer value, creating segmented transmission time slots. This segmentation allows multiple slaves to be addressed quickly while maintaining adaptability, as the trigger pulse duration remains short regardless of the number of slaves.
Data Source
AI summary
Slave devices, master devices, systems and methods are disclosed for bidirectional edge-based pulse width modulation protocol based communication. In an implementation, receiving a master trigger signal starts a timer having an associated time period in a slave device, and after the timer has elapsed the slave device transmits a response.