Af4-trigger hat pre LED resistor change

aF4 Frozen Feeder — ESP32 PoE Trigger

Replaces the inD connect WiFi dongle on the inD aquatics aF4 refrigerated frozen-food feeder with an Olimex ESP32-POE-ISO running ESPHome, triggering feeds via the aF4's 0-10V port and scheduled from Home Assistant.

How it works

ESP32-POE-ISO → GPIO32 → 220Ω → AQY212GS PhotoMOS → switches the feeder's own 12V supply (regulated to ~10.4V by an on-board LM1117-ADJ) onto the 3.5mm trigger jack. Safety guardrails (20s pulse, 5-min lockout, restore-off, flash-persisted boot lockout) are baked into the ESPHome config on-device; HA is scheduler only.

All of that sits on a PCB "hat" that plugs onto the ESP32's EXT1/EXT2 headers and carries both panel connectors, assembled by PCBWay. Rev F is the board to order. Rev E is the one that was fabricated and is installed and working — same circuit, but its 12 V jack was placed facing inward and is bypassed with a panel jack. Rev F corrects that and the socket mounting face in the fab data; it has not yet been fabricated itself. The rev C hand-wired protoboard is retired.

The trigger pin is GPIO32, not GPIO13. The Olimex board has a factory 2.2 kΩ pull-up on GPIO13 that can partially turn the PhotoMOS on during boot. See docs/aF4-pcb-notes.md.

Where to start

Three documents are live. STATUS.md is the only one that describes current state; it is rewritten, never appended to. aF4-MASTER-REFERENCE.md is the deep record — it carries a section index and is meant to be grepped by §N.N, not read whole. .claude/CLAUDE.md holds the durable facts and the routing table.

Folder map

The board

pcb/gen_pcb.py is the source of truth: it generates pcb/af4-trigger-hat.kicad_pcb deterministically from named coordinates, taken directly from the Olimex Rev N KiCad source so the sockets line up by construction. Edit the script, not the board file, then re-run it, pcb/post.py (fills the copper pours, runs DRC), pcb/check_jacks.py (proves both jacks can be plugged into, against the manufacturer's 3D models) and pcb/make_package.py (Gerbers, drill, BOM, centroid, fab notes, zips).

To order a board: upload pcb/af4-trigger-hat-rev-F-GERBERS.zip to PCBWay's fabrication line item and pcb/af4-trigger-hat-BOM.xlsx + pcb/af4-trigger-hat-centroid.xlsx to the assembly line item. Print hardware/enclosure/aF4-trigger-case-revF.stl and hardware/enclosure/aF4-trigger-lid.stl. Full procedure: docs/aF4-pcb-notes.md, then docs/aF4-assembly-guide.md. The rev-E zips are the frozen record of what was fabricated.

Vendor files (not in repo)

• ESP32-POE-ISO board CAD: Olimex hardware files
• AQY212 PhotoMOS STEP: Panasonic
• aF4 / inD connect product docs: inD aquatics

Key trigger rules (inD 0-10V spec)

Feed triggers on ≥9V held ≥15s (inD publishes 6s/10s/15s across three guides — design to the longest); feeds ≥5 min apart; port must see ~0V for >60s to re-arm. Connecting the link port overrides the aF4's internal 24h schedule — an offline ESP32 means no feeding at all. Measured OEM dongle trigger voltage 10.37V open-circuit (don't feed raw 12V).