Dual MCU Design Explanation

bunny5161

bunny5161

why their are two MCU ?

flux

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
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    Fun Turquoise Holodeck thumbnail
    Battery-isolated 16-channel medical-grade EEG front end using dual ADS1299 analog front-ends and an STM32F405 host with integrated WiFi and microSD (SDIO), featuring corrected isolation, and robust low-jitter clock distribution for dual ADS1299 #WiFi #microSD #Isolation #Clocking #ADS1299 #STM32

    Properties

    Diagram
    


  
    
  
  
    
  



""Patient Side""


""Host Side""















"2x8 Header\n(Pins 1-16)"
"Patient Analog Front End"
"Isolated Power"
"Digital Isolation"
"Low-Jitter Oscillator"
"Host MCU\n(STM32F405)"
"WiFi Module"
"microSD Card Slot"

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