Dual MCU Design Explanation
Thought for 1 min 12 sec
Short answer: we split duties between two MCUs to keep the EEG acquisition deterministic and quiet, while offloading wireless and app features.
- U3: real-time host for the dual ADS1299s, clocked SPI/DMA capture, precise timing, and local tasks like storage. This keeps jitter low and digital noise away from the sensitive analog front end.
- U8: handles wireless/connectivity and higher-level tasks so the acquisition MCU doesn’t get interrupted by networking stacks.
Benefits:
- Deterministic sampling and lower coupling into the analog front end (prioritize ground separation over supply separation to reduce noise return-path coupling).
- Cleaner isolation boundary: the noisy RF/stack side is kept off the patient-side analog domain.
- Robustness: connectivity issues don’t stall or jitter the data-acquisition loop.
If you’d prefer a single-MCU approach, we can discuss the trade-offs (more jitter/interrupt load near the AFE, tighter noise controls, and isolation constraints).
Prefer single MCU
Clarify MCU connection
Noise isolation guidance
Sampling requirements
Power/EMI concern
