# How CondomShot works: engineering a voice-activated condom launcher

> CondomShot has no microphone: a Siri Shortcut on the user's phone calls the launcher's local Wi-Fi endpoint (ESP32), which feeds one sealed condom packet from a 15-packet magazine and launches it with a soft flywheel throw into the user's hand.

By Henrik — founder & engineer, CondomShot · Last updated: 2026-07-08
Canonical: <https://condomshot.com/how-it-works/>

## Design goals (in priority order)

1. **The condom arrives intact** — sealed foil packet, undamaged, stored in condom-friendly conditions.
2. **The catch is easy and safe** — a gentle arc at conversation distance; a missed catch means a condom on the floor, nothing more.
3. **The moment feels great** — spin-up sound, LEDs, the catch. The theater makes people *want* to use protection.

## Voice pipeline: borrow the best recognizer you already own

The counterintuitive core decision: **the device itself has no microphone.** Embedded wake-word engines are hobby-grade; the phone in your pocket already carries the best speech recognition on earth — so CondomShot delegates to it.

- The device joins the local Wi-Fi and exposes a minimal web endpoint — in essence, a "fire" URL.
- A **Siri Shortcut** maps the user's chosen phrase (classic: *"abfeuern"* — "fire!") to a call to that URL; the ESP32 then runs the launch sequence.
- Any phrase, any language the assistant speaks — the trigger phrase is yours, not a fixed factory wake word.
- **Open trigger:** anything that can call a URL can fire it — smart-home buttons, Home Assistant automations, NFC tags.
- Privacy: a device with no microphone physically cannot listen or record. Voice stays with the assistant under its rules; the launcher only ever receives a web request on the local network. No CondomShot cloud, no account.

## Launch mechanism

A miniature **flywheel accelerator** (pitching-machine principle, tuned soft):

1. Motor spins the flywheel up (~1.5 s — intentionally audible; the spin-up is the drumroll).
2. Feeder pushes exactly one packet from the magazine into the wheel gap.
3. The wheel grips the stiff foil edge and releases the packet on a slightly upward arc.

A few-gram, draggy foil packet sheds speed fast and arrives floating at ~0.5–1.5 m. Launch energy is capped in firmware — never harder than a casual underhand toss. *(Numbers are preliminary prototype figures.)*

## Magazine

Brand-agnostic by design: gravity stack with compliant follower, adjustable for packet size, up to **15 condoms** of any major brand (Durex, Billy Boy, einhorn, …). Refills in seconds; no proprietary refills, ever.

## Safety & failure modes

- **Packet integrity:** rollers contact only the packet edge; test packets are inspected after launch runs.
- **Jam handling:** unconfirmed feed → cycle aborts, flywheel spins down; no double-feeds.
- **Face-distance safety:** even point-blank is harmless; guide rail launches upward-and-outward.
- **False triggers:** no always-open microphone in the device — a launch happens only when the trigger URL is actually called.
- **Storage:** enclosed indoor housing keeps condoms dark and at room temperature (latex ages with heat/UV).

## Preliminary test data (prototype — engineering targets, not certified specs)

| Metric | Value |
|---|---|
| Test launches to date | 500+ across prototype revisions |
| Packet damage observed | 0 |
| Misfire / failed-feed rate | < 2% per cycle, auto-recovering |
| Spin-up time | ~1.5 s |
| Catch distance | 0.5–1.5 m |
| Power | 5 V USB-C |
| Electronics | ESP32-C3 with Wi-Fi; local HTTP trigger endpoint, no microphone |

## Roadmap

Working prototype live → CE certification (electrical safety, EMC) → design-for-manufacturing → 1,000 units within 18 months. Preorders (€69, pay on delivery) fund this: https://condomshot.com/

Related: [Complete dispenser guide](https://condomshot.com/guide/voice-controlled-condom-dispenser/) · [Why it matters](https://condomshot.com/condom-access-and-sti-prevention/)