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).
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
Pricing & Availability
Distributor
Qty 1
Arrow
$100.45–$190.86
Digi-Key
$120.93–$122.68
LCSC
$81.79–$101.52
Mouser
$194.58
TME
$23.96
Verical
$93.28–$200.73
Controls
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