How to make your own Baby monitor device with Raspberry Pi

Someone contacted me for a hobby project to monitor his children’s room and after the project, I decided to dabble a little into a baby monitoring device. At least, I came out with something useful although the device is not yet complete but it will surely serve.

See also:

This system consist of two parts:

  • An android app
  • Main controller (Raspberry pi)

The idea behind this is just a system to monitor a child’s environment (temperature and humidity), outside presence for security, and others.

To recreate this project, you will be needing these components:

I plan to add a pulse sensor in future so anticipate for that.



ADS1115 is a 16bit analog to digital converter that converts analog signal to digital signal. it communicates with the RPi through i2c bus. RPi is uncapable of handling analog signals. Connect ADS1115 to Rpi and sound sensor:

  • ADS VCC –> RPi 3.3v (pin 1 or 17)
  • ADS GND –> RPi GND
  • ADS SCL –> RPi SCL (pin 5 BCM 3)
  • ADS SDA –> RPi SDA (pin 3 BCM 2)
  • ADS A0 –> Sound Sensor A0 pin


Sound Sensor detects sound, it has four pins:

  • VCC pin (connect to 3.3volts)
  • GND
  • A0 (outputs analog signal)
  • D0 (outputs digital signal)

The A0 pin from sound sensor goes to ADS A0 while the D0 pin connects to RPi pin 37 (BCM 26). Adjust the potientmeter (sensitivity) counter-clockwise till the led starts blinking on detecting sound.


OLED display communicates with the RPi through i2c bus and requires 3.3volts to power although it will run fine with 5volts. The conectios with RPi are as follows:

  • oled VCC –> RPi 3.3volts
  • oled GND –> RPi GND
  • oled SCL –> RPi SCL (pin 5 BCM 3)
  • oled SDA –>RPi SDA (pin 3 BCM 2)

You can connect the cables from the ADS1115 and OLED display to RPi SCL and SDA, all the devices connected to the i2c bus will be recognized. Run this command: sudo i2cdetect -y 1 to confirm.

You can setup the Camera feed Streaming by using this my earlier post or you can just stick with raspistill (takes pictures remotely from the Android app but stores the files in the Raspberry Pi SD card).

PIR motion sensor goes pin BCM 24 and Buzzer goes to BCM 25. The fritizing diagram below should help you out.

monitor - steinacoz
monitor – steinacoz



Python Script:

You will be needing these Python libraries to get you through:

The full python code is available on my Github.


Android App:

The company Android app is written in Java, is just a sterotype of the other Android app I have been writing for my tutorials. You can take a look at the code from my Github.

The only external library you will be needing is Pubnub Java Android SDK.


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