Research · Prototype architecture
B4 Sentinel — Confined Space
A multi-gas confined-space monitoring platform using electrochemical front ends and multiplexed sensing.
Problem
Confined-space crews need multi-gas information in environments where sensor cross-talk, analog front-end complexity, and unreliable connectivity can undermine a simple detector design.
Description
What I built or investigated
B4 Sentinel is a multi-gas architecture using electrochemical sensing, AD5940 front ends, ADG704 multiplexing, and an ESP32-class controller. Its controller and board work shares the broader Sentinel research PCB platform while keeping the electrochemical analog front end specific to confined-space sensing.
Iterations
The work did not happen in one jump.
- 01
Built the sensor-channel and analog-front-end architecture.
- 02
Worked through BOM cost and board partitioning for low-volume prototypes.
- 03
Designed the system around local processing rather than a mandatory cloud connection.
- 04
Used the first sensor-board bring-up failure elsewhere in the platform to create a stricter schematic and power-up review process.
Result
Where the project landed
Prototype architecture, BOM, and board-design work prepared for further fabrication and validation.
Lessons
What carried forward
- Electrochemical sensing quality depends heavily on the analog front end and calibration plan.
- Shared platforms reduce cost only when channel isolation and failure modes are designed deliberately.
Images & evidence
Work in context
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