Turn an iPhone and a $20 smart plug into a darkroom timer

Film photographer built a phone-driven f-stop timer that switches a cheap smart plug for darkroom printing.

See pricing page1 weekendIntermediateSource linked

Source

pentakkusu on Hacker News · 2026-10-06 · Project link

Written in our own words. Credit to the original author. Link checked 2026-10-15.

What they did

Film photographer built a phone-driven f-stop timer that switches a cheap smart plug for darkroom printing.

Result (as claimed)

Replaced a multi-hundred-dollar timer with phone plus $20 plug.

Tools they used

The source does not name specific tools.

Cost: Pricing depends on the tools you pick; check each official pricing page.

Set it up

Define the job
Say exactly what you want done and what the agent may and may not do on your behalf.
Share only what is needed
Give your AI agent the minimum files or access required. Avoid sharing passwords in chat when a safer login flow exists.
Review the plan
Ask the agent to show its plan or draft before it acts, and approve each step that has real consequences.
Check the result
Confirm the outcome yourself (order placed, request sent, document understood) and keep a record.

Copy the full setup prompt

Paste into your agent and it will walk you through the setup, asking before anything that sends, posts or spends.

You are helping me set up this AI use case end to end in Claude Code.

Goal: Turn an iPhone and a $20 smart plug into a darkroom timer
What the original author did: Film photographer built a phone-driven f-stop timer that switches a cheap smart plug for darkroom printing.
Reported result (as claimed by the author): Replaced a multi-hundred-dollar timer with phone plus $20 plug.
Source: https://news.ycombinator.com/item?id=49978595
Tools they used: not named in the source
Category: Personal & life

Please:
1. Ask me 3 short questions about my situation (accounts I have, budget, what I want the output to look like).
2. Propose a step-by-step plan using these tools or cheaper alternatives, with the time and cost of each step. Use official pricing pages; say "check pricing" if unsure.
3. Then do the setup with me one step at a time, waiting for my OK before anything that sends messages, posts publicly, spends money or deletes data.
4. Finish with a checklist to run it again next time.

You are helping me set up this AI use case end to end in Codex.

Goal: Turn an iPhone and a $20 smart plug into a darkroom timer
What the original author did: Film photographer built a phone-driven f-stop timer that switches a cheap smart plug for darkroom printing.
Reported result (as claimed by the author): Replaced a multi-hundred-dollar timer with phone plus $20 plug.
Source: https://news.ycombinator.com/item?id=49978595
Tools they used: not named in the source
Category: Personal & life

Please:
1. Ask me 3 short questions about my situation (accounts I have, budget, what I want the output to look like).
2. Propose a step-by-step plan using these tools or cheaper alternatives, with the time and cost of each step. Use official pricing pages; say "check pricing" if unsure.
3. Then do the setup with me one step at a time, waiting for my OK before anything that sends messages, posts publicly, spends money or deletes data.
4. Finish with a checklist to run it again next time.

You are helping me set up this AI use case end to end in Grok Bot.

Goal: Turn an iPhone and a $20 smart plug into a darkroom timer
What the original author did: Film photographer built a phone-driven f-stop timer that switches a cheap smart plug for darkroom printing.
Reported result (as claimed by the author): Replaced a multi-hundred-dollar timer with phone plus $20 plug.
Source: https://news.ycombinator.com/item?id=49978595
Tools they used: not named in the source
Category: Personal & life

Please:
1. Ask me 3 short questions about my situation (accounts I have, budget, what I want the output to look like).
2. Propose a step-by-step plan using these tools or cheaper alternatives, with the time and cost of each step. Use official pricing pages; say "check pricing" if unsure.
3. Then do the setup with me one step at a time, waiting for my OK before anything that sends messages, posts publicly, spends money or deletes data.
4. Finish with a checklist to run it again next time.

The Daily 5