Baby Monitor Technology

We’ve been using this video baby monitor that we received as a gift until just recently, when it started to die. Random bursts of static while you’re trying to sleep are just no fun. It’s an analog device, so the camera part is simply broadcasting audio and video at 900mhz, and the receiver picks up whatever’s there and displays it and plays the audio portion out the speaker.

There’s no security, so every now and then we’d hear the neighbor’s 900mhz cordless phone through the monitor. I don’t know for sure that they could hear our monitor on their phone, but it wouldn’t surprise me. So when looking for a replacement, security was definitely a factor.200804080650

Really there’s not much to a baby monitor. It needs a camera and microphone and some way to broadcast wirelessly, and a receiver that can pick up the signal and present it.

There are off-the-shelf components that can do this job and in a secure, digital manner. And finally, a company has put these together in an actual baby monitor product that doesn’t suck: The Safety 1st 08280-High-Def Digital Color Video Monitor.

Check out some of the features:

  • 100% private, no static, no interference
  • Remote digital zoom and pan (note it’s digital zoom and pan, so it’s not perfect, but the camera is presumably higher resolution than the display so you’re not losing that much)
  • Auto-night vision (it shines infrared light and picks up a black&white infrared picture at night)
  • H.264 video
  • WiFi-friendly 2.4ghz signal (using some technique that causes it to not interfere with 802.11)

Nice. The only problem? It’s $319.

That’s a lot for a baby monitor. And the part that gets me is that this monitor probably costs about the same, or less, to produce, than the one we already have. It’s very small and light, not the big CRT that the previous one had, and is presumably using a lot of off-the-shelf parts for the complex parts like the H.264 video and wireless signal.

200804080659-1Actually, if you look at the parts in the receiver, a Nintendo DS would be more than capable to do the job it’s doing.
The DS has a better screen, better sound, probably better battery life, and can be used for other things. It’s got 802.11 networking built-in, and it sells for $139.

Once you’ve got the DS you’d need an 802.11 camera and some software. You can buy an 802.11 camera like this one for $89, and then it just comes down to software.

That’s the hard part for a DIY project, but I wonder if there would be a market for a baby monitor application for the DS that would let you use it and a generic 802.11 camera as the world’s best baby monitor?