Just in time to build for the holidays, we bring you this project: a talking Santa DIY Christmas ornament for kids! (Or really for anyone who’s a kid at heart.)
Doesn’t he look cute? And here’s the kicker: you can record whatever message you want Santa to say, and he’ll say it whenever something gets close to him!
If you decide that you want to change the message, you can do it with the press of a button.
A note of caution: while kids will definitely enjoy being surprised by this ornament, recording messages for Santa to say, and helping build the project, this DIY Christmas ornament for kids does require an adult’s help. It also requires soldering (but it’s easy, and we’ll show you how to do it).
Before you continue, if you want a crash course in understanding these concepts, check out our post on electrical current, resistance, and voltage.
If you aren’t already familiar with breadboards, you can check out this post on how to use a breadboard first.
We’ll explain the parts we used, and then we’ll give you step-by-step instructions to build your own talking Santa DIY Christmas ornament for kids.
You can check out our video tutorial here and subscribe to our YouTube channel to keep up with new projects.
We explain everything below as well (but you have to watch if you want to see what our Santa said!)
Designing the Santa ornament circuit: A proximity sensor, audio playback circuit, and resistor values
We want to build a Christmas ornament that will surprise people by talking when someone gets close to it. So we needed to trigger our circuit by the presence of a nearby object.
If you read our post about building a security alarm for a blanket fort, you might remember that we used a proximity sensor to detect the presence of an intruder.
In that post, we explain how a proximity sensor works and how to wire it up on a breadboard.
When a nearby object triggers the proximity sensor, the sensor puts out an electric current. We can use that current to trigger the audio playback circuit.
The audio playback circuit that we ordered for this project came pre-assembled, except for the speaker plug connectors, which we needed to solder to the speaker contacts. More on that below.
We also needed to calculate resistor values for the infrared-emitting diode in the proximity sensor.
Using Ohm’s law: voltage / resistance = current
Voltage is measured in volts.
Resistance is measured in ohms.
Current is measured in amps.
We’re using a 3-volt battery pack (with two 1.5-volt AA batteries) to power the circuit.
To determine the maximum current, we can look at the data sheet for our proximity sensor. We see that the infrared-emitting diode’s maximum rated forward current is 50 milliamps, which is 0.05 amps.
Plugging in voltage and current, we can use Ohm’s law to calculate the needed resistance: 60 ohms.
Supplies for this DIY Christmas ornament for kids
Two 30 ohm resistors
Printable Santa graphic
String or wire ornament hangers
Steps to build this DIY Christmas ornament for kids
Step 1: Insert the proximity sensor and resistors
Here’s a photo of our completed circuit.
Start out by inserting the proximity sensor so that it straddles the groove going down the middle of the breadboard. Make sure that the infrared-emitting diode (the clear side) is on the bottom and the phototransistor (the dark side) is on the top, as shown above.
Next, break out the resistors. We calculated that we needed 60 ohms of resistance. Since 60 ohm resistors are not individually manufactured, we can achieve this resistance by using two 30 ohm resistors wired in series (one after the other in the circuit).
Put the first leg of a 30 ohm resistor in one of the breadboard holes that is electrically connected to the lower left contact of the proximity sensor. Place the second leg of that resistor in a hole in one of the neighboring empty rows to the left.
With your second 30 ohm resistor, place one leg in one of the holes that is electrically connected to the second leg of the first 30 ohm resistor, and the other leg in a neighboring empty row of holes to the left. You can think of that row of holes as your negative bus.
Make sure that the arrangement of your resisters matches what you see in the picture.
Step 2: Make connections from proximity sensor pins and resistors
Next, use a small jumper wire and place one leg in one of the holes electrically connected to the lower right contact of the proximity sensor. Put the other leg of the jumper wire in a neighboring empty hole of rows to the right. You can think of that row as your positive bus.
With the second small jumper wire, place one leg in one of the holes electrically connected to the upper right contact of the proximity sensor. Put the other leg of the jumper wire in a neighboring empty hole to the right, directly (or nearly) aligned with the positive bus below the groove.
Then, put one leg of the third small jumper wire into one of the holes that is electrically connected to where you inserted the last wire. Put the other end of the third jumper wire into one of the holes across the groove in the positive bus.
The arrangement of your three small jumper wires should match that of the three short yellow jumper wires in the picture above.
Step 3: Solder the plug leads to the speaker contacts and plug into audio playback circuit
If this is your first time soldering, check out this post, or watch the video above.
After you solder the ends of the speaker plug connector to the speaker, insert the plug into the audio playback circuit.
Step 4: Connect the audio playback circuit
For this step, you will need 3 male-to-female jumper wires. Alternatively, you can make a male-to-female jumper wire by connecting a male-to-male jumper wire to a female-to-female jumper wire.
Plug the male end of one jumper wire into one of the holes on the breadboard that is electrically connected to the upper left contact of the proximity sensor.
Plug the female end of that jumper wire into the audio playback circuit pin labeled “P-E.” Now, when the proximity sensor is triggered, the current will be transmitted to the audio playback circuit
We also have to provide power to the audio playback circuit.
Plug the male end of your second male-to-female jumper wire into your “positive bus.” Remember, we made our positive bus the rightmost row in which there are any wires connected. Plug the female end of that jumper wire into the audio playback circuit pin labeled “VCC.”
Finally, plug the male end of your third male-to-female jumper wire into your “negative bus.” Remember, that’s the leftmost row in which there are any wires connected. Plug the male end of that jumper wire into the audio playback circuit pin labeled “GND.”
Step 5: Connect the battery and test it out!
Insert the positive lead from your battery holder into your positive bus (the rightmost row with wires– you already used a jumper wire to connect the rows above and below the groove into a long positive bus).
Insert the negative lead from your battery holder into your negative bus (the leftmost row with wires on the bottom half of the breadboard).
Now, you should be able to record a message by holding down the red REC button on the audio playback circuit, saying your message, and then releasing the button.
Play back your message by either moving your hand close to the proximity sensor or by pressing the “PLAYE” button.
If you want to change the message, simply press down the REC button and record again.
Step 6: Cut out Santa and tape the circuitry behind him
Download and print the Santa image onto cardstock paper.
Cut out Santa and also cut a small hole for the proximity sensor to poke out (we made the hole in the rim of his hat.
Arrange all the circuitry (except the battery pack) to hide it behind Santa, and then use making tape to secure it in place.
Try not to tape over the speaker, or you will muffle the sound.
Step 7: Hang the DIY Christmas ornament for kids on the tree!
You’ll want to pick a place on the tree where people will be getting close enough to trigger the proximity sensor (within a couple of inches). Try picking a lower branch among some presents.
Hang the ornament on the tree with an ornament hanger or a piece of string.
Rest the battery pack on a nearby low branch to hide it. You may want to secure it there with some string or wire.
If you enjoyed this project or have questions, please let us know! Are there other projects you’d like us to build? Please leave us a comment!
You can also check out our collection of cool engineering projects.