Slumbi/Guides/Old iPhone as a baby monitor
How to use an old iPhone as a baby monitor
The phone you stopped carrying two upgrades ago has a good lens, a microphone that picks up a whimper across a room, and no monthly fee. Here is how to make it the camera in the nursery.
What the old phone needs
- iOS 15 or later. That reaches back to the iPhone 6s and the first-generation SE, so almost anything from 2015 onwards qualifies.
- A charger. This is the one requirement people skip. A phone that streams video and holds a network link all night will not last on battery, and a monitor that dies at 02:00 is worse than no monitor. Leave it plugged in.
- No SIM card. Over Wi-Fi or Bluetooth the nursery phone needs no mobile plan at all.
It does not have to match your current phone. An old model as the camera and your everyday phone as the viewer is the normal setup, not a compromise.
Setting it up
- Install Slumbi on both phones.
- Sign both of them in to the same account. That shared account is what pairs the two devices — there is no code to type and no QR to scan, and a phone on a different account cannot see your units at all. If the old phone is sitting next to you, an already signed-in device can hand the account over without you re-entering the password.
- On the nursery phone, tap Baby Unit. Give it a name when it asks — that is what you will see in the list later, which matters the day there are two of them.
- On your phone, tap Parent Unit and pick the unit. It appears by itself; the picture follows.
Where to put it
Somewhere solid, out of reach, with the whole cot in frame — a shelf or a chest of drawers a metre or two away works better than anything clamped to the cot itself. Cables near a cot are the actual hazard here, so run the charger away from the rails and keep the slack out of the room.
You do not have to get the framing perfect. The camera zooms from the parent side, so you can start wide and pinch in on the face without going back into the room.
The back camera is usually the right one. It is the better sensor on every iPhone, and the front camera is only worth choosing if you also want the screen as a night light — that trick only works with the front camera, because the light and the lens have to be on the same side.
Leave the app in front, not the phone locked
iOS stops the camera for an app that is not frontmost. Slumbi keeps running and keeps the sound going — the parent side switches to an honest "Audio Only" state rather than showing a frozen frame — but the video stops until the Baby Unit screen is in front again.
So do not lock the nursery phone. To keep the room dark, use Slumbi's own controls instead: the moon button drops the backlight to zero, and Power Saving Mode replaces the preview with a dim soothing scene after about half a minute of no interaction. Both keep the camera alive.
What it costs
Monitoring over your home Wi-Fi and over Bluetooth is free and unlimited. Watching from outside the house, over the internet, is the paid part. So the drawer-phone setup for the next room — which is what most nights actually are — costs nothing beyond the phone you already own.