Baby monitors give parents piece of mind by letting them keep an ear (or eye) on a kid’s room while wondering the house. But you don’t need to spend a lot of money on a high-end model to get decent performance.
Matt Karr decided to build one himself using little more than a $35 Raspberry Pi and a Blue Yeti USB microphone (which, admittedly sells for around $100 — so buying a baby monitor might be cheaper… but not as geeky).
You can find instructions for setting up the baby monitor at Karr’s website. In a nutshell, you just need a Raspberry Pi running Raspbian Linux, a supported USB microphone, and a few lines of code that allow you to capture audio and send it to a remote source.
Then you can use a second Raspberry Pi or any computer running Linux to monitor the incoming audio, allowing you to hear if your baby’s crying.
via Raspberry Pi