Modernize a legacy EPROM-based industrial airflow monitor into a battery-powered, ATEX-ready embedded system. Measures duct static pressure via Honeywell ABP2 sensor, triggers alarms when airflow drops below calibrated threshold. Target: 12–18 months on 2×AA batteries, intrinsic safety compliance.
Scope
✅ Hardware: Finalize schematic/PCB for PIC16F18446, integrate JAZZ-AC-W LCD (SPI, no backlight), DRV5032 Hall sensor for magnetic calibration, passive piezo drive, single red LED, ultra-low-power architecture (XC6220 LDO @ 0.6µA).
✅ Firmware: Calibration state machine (5s magnet hold → pressure averaging → EEPROM+CRC), real-time monitoring with hysteresis, ST7567 SPI driver for icons (▲/✖/battery), <5µA sleep current.
✅ ATEX Readiness: IS Zener barriers, current-limiting resistors, ≥1.5mm creepage, IS-earth terminal, component traceability, pre-assessment documentation.