dropspider-inline

DropSpider, Mechanism A: In-Line Single-Axle Clutch Spool (ISCS), Rev C.1. A Halloween prop, mounted on a porch ceiling or turned over on the porch beam's inside face (doc 06), that drops a foam spider 0.5 to 1.2 m when someone walks toward a doorway, then winds it back up and re-arms on its own. Zero power while waiting.

Code: https://github.com/Maestro8484/DropSpider-inline. Project page: https://theschmidtwithin.com/bench/#dropspider

Sibling project name reserved: dropspider-tiltspool (Mechanism B, servo-driven tilt-spool free-fall). Not started. This repo is Mechanism A only.

How it works

Stepper motor to coupler to 6 mm rod. The spool rides the rod on a one-way clutch bearing. On a drop, the motor spins fast in the unwind direction and the spool runs down behind it; the clutch lets the spool lag but never overrun, so the motor sets the drop speed and the stopping height. On rewind the clutch locks and the motor winds the spider home, where the line's stop bead lifts a hinged flap under the fairlead and clicks a limit switch. A servo-driven finger in a ratchet then holds the spool with no power. An LD2450 radar at the door fires only on people walking toward it, timed so the spider arrives as they reach the doorway.

Repo map

Each doc has one job, marked in bold below where it matters: a handoff holds only work still to do, finished work goes to the changelog, the order of future work is the roadmap, problems go to the issues list, bench results to the log, and everything else describes the device as it is now.

Path	What
docs/01_mechanical_design.md	design spec, stack-up, lock mechanism, direction rules, print settings
docs/02_electrical.md	pin map, power, driver setup, logic-level check
docs/03_sensor.md	LD2450 (primary) and LD2410C (fallback): placement, trigger rule, app check
docs/04_firmware.md	cycle, serial commands, rewind math
docs/05_assembly.md	step-by-step assembly with pictures
docs/06_installation.md	doorway geometry, heights, fastening, safety
docs/07_commissioning.md	bench and on-site test checklist with pass criteria
docs/08_open_items.md	issues: what is verified, what is not, risks; closed items one line each
docs/09_fairlead_switch.md	fairlead, hinged flap and KW12-3 limit switch
ROADMAP.md	roadmap: every piece of work still to do, in order, one line each
CHANGELOG.md	changelog: finished work, newest first
docs/handoff_task1_firmware.md	handoff: bench tests T1 to T8, and the spool-to-flap fix before them
docs/handoff_spool_onepiece.md	handoff: one-piece spool and ratchet, no supports, bearing hole that grips, separator clear of the finger
docs/handoff_sensor_bearings.md	handoff: the LD2450 radar as the trigger (the name is historical; bearing care is in doc 01)
docs/M1_fix_handoff.md	reference: the Rev C.1 clutch fix and motor-led drop, why it works, and the T1 to T8 test table (the name is historical)
cad/generate.py, cad/fairlead.py, cad/inverted.py	source of truth for every printed part (inverted.py: the device turned over on the porch beam, doc 06) (tools\regen_cad.ps1 rebuilds STLs and images)
cad/stl/	print-ready files. cad/retired/ holds obsolete parts and their code, docs/retired/ obsolete docs and pictures: do not print or follow them
platformio.ini, src/, include/	firmware, standard PlatformIO layout, 30-pin ESP32 DevKit V1 (38-pin NodeMCU-32S also works)
secrets.ini.example	template for secrets.ini: WiFi name, password, update password (never committed)
docs/commissioning_log.md	log: every bench and install result, dated, failures included
bom/BOM.csv	every part, ordered or still to buy
scripts/update_firmware.bat	double-click to update the firmware, by WiFi or by USB
tools/esptool_noreset.py	USB flashing helper the update script uses
tools/console.py	send console commands over USB or the network, print the replies
tools/requirements.txt	Python packages for the tools
tools/*.ps1	same as the .bat files for PowerShell; regenerate CAD and images

Quick start

1. Print the parts in cad/stl/ (settings in doc 01).
2. Buy the "TO BUY" lines in bom/BOM.csv.
3. Assemble per doc 05.
4. Wire per doc 02. Meter the 5 V buck (must read 4.95 to 5.05 V) and set driver Vref to 0.85 V first.
5. Copy secrets.ini.example to secrets.ini and put in your WiFi name and password.
6. Plug the board in by USB, double-click scripts\update_firmware.bat, pick 2 (USB), then run doc 07 on the bench.
7. From then on, the web page at http://dropspider.local is the console, and firmware updates go over the network (doc 04).
8. Install per doc 06.