Introduction: Automatic Baby Mobile Using Sound Sensor of Smartphone

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Welcoming a baby is for sure one of the most beautiful phases of life. But it is challenging as well at the same time, especially if you're a first-time parent yourself. Stopping the cries in the middle of the night, making the baby flash his/her toothless smile is one of the most challenging things to do and having a shut-eye seems to a distant reality which is almost a fantasy. But not anymore! This unconventional baby mobile that can easily be controlled using Dabble, our indigenously developed mobile application, is here to help you out. Whenever the baby cries, the app senses it and gets the mobile going et voila! Everybody is all smiles again!

Even if there isn't a newborn with you, the mobile is going to make the ideal gift for other new parents! Why are you still here? Let's get going!

Step 1: Things You'll Need


  • evive
  • Bluetooth Module HC05
  • DC Motor
  • Thick Cardboard
  • Color Paper
  • Hot Glue Gun

Software and Application

Step 2: Making of the Baby Mobile’s Base

The first thing that we need to do is, make the baby mobile. The best part is that the whole baby mobile is made using cardboard.

You can make anything to hang your mobile from. I decided to make a flower.

Take the cardboard and make the outline of the design you want.
I took the cutout of my flower.

Paint it to make it look attractive. Keep it aside.

Step 3: Make the Decoration

You can make anything that you wish to make.

I made some clouds, stars, flowers, and a moon. I have made these decorations using colored paper.
You can use any material.

Now to hang these objects, we are using the colored string.
Make sure that the string you are using is strong enough to hold their weight and rotate nicely.

Now cut the string into pieces. The strings can be equal in length or can be of different length.

Once you have the string and the paper cutouts with you, glue the objects to the string.

Step 4: The DC Motor

As we are all aware that we need to rotate the mobile robot, we need a component to complete that work.

Take a piece of cardboard and cut it in the width of the DC Motor.

Wrap the cardboard piece around the DC Motor using Hot Glue. Make sure that both the shafts are free.

One is for attaching the mobile and the other one is for the free rotation. Paint it.

Attach the wheel to one of the shafts.

Step 5: Making of the Mobile

Now take the mobile base that we have kept aside and the decorations.

Make a hole in the base and into that hole, insert the string and fix it using glue.

Repeat the same process until you have all the strings attached to the base.

Now you have the assembly of the DC Motor and the wheel.

Glue the wheel on top of the mobile base.

Step 6: Completing the Process

Now take longer cardboard upon which we will be mounting our mobile.

Glue the ends in such a way that the wires can pass from the hollow column.

Paint it.

Once done, Place the assembly near the baby's cradle.

Step 7: Code

Upload the following Arduino Code to evive.

Step 8: Connection

Connect the DC Motor to Motor Channel 1 and Bluetooth Module as shown in the figure.

Step 9: Working

The Mobile that we have made here is the one that automatically starts rotating when the baby cries.

The reason behind it is, you need to put your Smartphone near the baby and connect Dabble to the Bluetooth Module of evive.

Among many features of Dabble, one of the features is phone sensors. Out of the many sensors that we have on our phone, the one we are using in this project is the Sound Sensor.

Thus, on the sound sensor among the list of sensors.

As soon as the intensity of the sound reaches a certain level, the signal is sent to evive. As a result, the DC Motor starts rotating and the baby will be happy to see it.

Step 10: Conclusion

With this, your DIY Dabble-controlled baby mobile is ready to spread some smiles! Happy parenting!

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