IoT Environmental Monitor Architecture

flux

Below is a clean, production-oriented system architecture for the EcoSense IoT Environmental Monitor, aligned with your project requirements. Based on knowledge base guidance, I’ve included USB protection best practices (PTC fuse, bidirectional low-capacitance TVS, common-mode choke), low-power architecture elements (low-Iq regulators, load switches for sensor power domains), and general ESD/layout guidance (solid ground plane).
Mermaid block diagram
Diagram



  
    
  
  
    
  



Power Supply Block


Processing Unit Controller Block


Memory Block


Input Block Sensors


Communication Block


Processing & Logic Block


Clock & Timing Block


Debugging & Programming Block


Thermal Management Block


Protection Block


PCB Interconnect & Routing Block




















































































Power Supply Block
Protection Block
Processing Unit Controller Block
Memory Block
Input Block Sensors
Communication Block
Processing & Logic Block
Clock & Timing Block
Debugging & Programming Block
Thermal Management Block
PCB Interconnect & Routing Block
all
USB C Power Input
PTC Resettable Fuse
Bidirectional TVS USB Data Power
USB Common Mode Choke
Power OR In Battery USB
Battery Charger IC
Li ion Battery Pack
Battery Protection Circuit
Low Iq Buck LDO Rails
Load Switches Sensor Power Domains
Fuel Gauge Battery Monitor
Wi Fi MCU SoC
External Flash Optional
Temperature Sensor High Precision
PM2.5 Optical Sensor
VOC Gas Sensor
CO2 Sensor
Wi Fi 802.11 b g n
UART GPIO Interfaces
I2C Bus Shared
SPI Optional
Low Power Domain Control
Analog Front End Filters As Needed
Main Crystal or TCXO
RTC Low Power Optional
Programming Header SWD UART
Diagnostic Logging Port
Heat Spreader for Hot Sensors
On Board Thermal Sensing
ESD Arrays for IO and USB
Input Protection Schottky TVS PTC on External IOs
Solid Ground Plane
Low Impedance Power Planes
Sensor Partitioning Analog Digital
Notes and rationale anchored to knowledge base guidance
  • USB and ESD: The Flux knowledge base recommends PTC resettable fuses for overcurrent protection and placing the PTC right after the USB connector when using a power OR-ing device. It also recommends bidirectional TVS with capacitance below 1 pF per data line and a common-mode choke on USB to maintain signal integrity after TVS clamping. I’ve included all of these in Protection/Power.
  • Battery charging and user safety: The knowledge base suggests adding charging status indication, polarity protection, and battery protection when building chargers for inexperienced users. The CHG, PROT, and MON blocks account for this, with optional status LEDs/GPIOs to MCU.
  • Low-power architecture: For 30-day battery life, the knowledge base recommends sub-5 µA sleep using low-Iq regulators and load switches to fully power-gate sensor domains. The BREG and LSEN blocks enforce this, and LPCTRL ties MCU control to switches.
  • Grounding/EMC: The knowledge base cautions against star-point grounding for ESD; use a solid ground plane. The PCB block includes a continuous GND plane and explicit analog/digital partitioning around sensitive sensors.
If you want, I can adapt this into a concrete parts plan next:
  • Select a Wi-Fi MCU and crystal, a USB-C receptacle and protection chain, a charger + fuel gauge, low-Iq regulators, load switches, and representative sensors for PM2.5/VOC/CO2/temp.
Select Wi-Fi MCU
Choose Li-ion charger
Pick USB TVS
Define ground plane
Select load switch
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