Turn a spare ESP32 box into a baby monitor that only wakes parents after 10 minutes of fussing, built with Claude
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- by pugio (Hacker News)
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Evidence: Described by posterThe person describes what happened in words, without screenshots or video.
Outcome
pugio and their spouse were sleep-training their baby, who wakes a few times a night and either babbles back to sleep or fusses for 10 minutes before a parent needs to go in. With a spare esp32-box-3 and a few rounds with Claude, they built a baby monitor that tracks how long the baby cries or fusses, streams audio only after 10 minutes, and sends notifications at 30 seconds and at 10 minutes. The log shows the baby often wakes 1-2 times a night and resettles almost immediately, and the parents only wake when the audio comes through. During the day it tells them when naps end.
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Prompt Recreated prompt
The source didn't share its exact prompt, so we wrote this from what it describes.
Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points. Goal: Help me build a simple baby monitor that only alerts me when crying lasts longer than I choose. What I can give you (ask for whatever's missing): - The device I have (board, microphone): [DEVICE] - How long before it should alert me: [MINUTES] - How I want alerts (phone notification, audio stream): [DETAILS] Rules: - Explain the plan in plain steps before writing code. - Track how long crying or fussing lasts and alert only after my time limit. - Log wake-ups with times so I can see patterns. - Tell me how to test it before relying on it overnight, and remind me it doesn't replace safe-sleep checks. - Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify. Output: Working code, set-up steps and a short test plan. You'll know it worked when: we sleep through brief wake-ups and get woken only when the baby needs us.
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Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points. Goal: Help me build a simple baby monitor that only alerts me when crying lasts longer than I choose. What I can give you (ask for whatever's missing): - The device I have (board, microphone): [DEVICE] - How long before it should alert me: [MINUTES] - How I want alerts (phone notification, audio stream): [DETAILS] Rules: - Explain the plan in plain steps before writing code. - Track how long crying or fussing lasts and alert only after my time limit. - Log wake-ups with times so I can see patterns. - Tell me how to test it before relying on it overnight, and remind me it doesn't replace safe-sleep checks. - Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify. Output: Working code, set-up steps and a short test plan. You'll know it worked when: we sleep through brief wake-ups and get woken only when the baby needs us.
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Our rewrite with extra checks. The poster didn't test it.
Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points. Goal: Help me build a simple baby monitor that only alerts me when crying lasts longer than I choose. What I can give you (ask for whatever's missing): - The device I have (board, microphone): [DEVICE] - How long before it should alert me: [MINUTES] - How I want alerts (phone notification, audio stream): [DETAILS] Rules: - Explain the plan in plain steps before writing code. - Track how long crying or fussing lasts and alert only after my time limit. - Log wake-ups with times so I can see patterns. - Tell me how to test it before relying on it overnight, and remind me it doesn't replace safe-sleep checks. - Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify. - Add a daytime mode that just notifies me when a nap ends. Output: Working code, set-up steps and a short test plan. You'll know it worked when: we sleep through brief wake-ups and get woken only when the baby needs us. Before you finish: re-read my goal and constraints, check your answer against each one, and list anything you assumed or couldn't confirm.
Source
https://news.ycombinator.com/item?id=48800997
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