In this tutorial we will build a simple circuit that uses a 555 timer and a Bare Paint potentiometer to make an interactive noise-maker. Before you dive into this tutorial it is worth checking out one of Matt's tutorials on building a potentiometer using Bare Paint. It is a good introduction to painted potentiometers, but not essential if you don't have an arduino. Also, if you are new to the 555 timer and are interested in playing around some more with this little chip, check out one of our earlier tutorials here.
By the end of this tutorial you should have a working 555 noise maker circuit connected to a potentiometer made from paper and Bare Paint. You will be able to change the sound of coming out of the speaker by changing the position of the slider on the painted potentiometer.
In this tutorial we will need to connect to the paint again from our breadboard. Last time we used paperclip wires, but this time we are going to try something else. We are going to use a bulldog clip to connect more securly to the paint and use the slider wire to vary the position on the painted strip.
Step 1: Components
Step 2: Materials
First you should gather the appropriate materials mentioned above:
1. A jar of Bare Paint, paint brush and paper, or use a Bare Pen
2. A 1K Ohm resistor
3. Two electrolytic capacitors around 0.68uF (0.68uF = 680nF = 680 000pF)
4. A small speaker or piezo transducer
5. A 555 timer IC (we are using the LM555CN by siemens)
6. Some wire and a bulldog clip to make your bulldog connector wire (see Connecting to Bare Paint for other methods)
7. Solder-less breadboard and some jump wires
8. Some paper or other non-conductive material to apply the Bare Paint
9. A 9V Battery and a battery clip with wires
Step 3: Painting the Potentiometer
The most basic way to think of a potentiometer, or variable resistor in this case, is a long piece of conductive material that can be tapped off with a slider at different lengths. In our case the material is Bare Paint and our slider is simply a long piece of wire. Depending on what length you want to 'tap off' from the painted line you can vary the resistance across the potentiometer. The longer the painted piece you 'tap off' the higher the resistance.
Step 4: Making a Bulldog Wire Connector and a Slider
Take the other wire and connect one end to your breadboard (see schematic) and leave the other end free for sliding. We can simple use the exposed end of the wire to make contact with the paint and generate noise.
Step 5: Circuit Diagram and Breadboard Schematic
Make sure to double-check your connections using the circuit diagram and breadboard schematic (download from these links). You can use this while you follow along in the tutorial video, pausing the video when you need to get a closer look at which tracks are being connected.
Step 6: Placing the Components and Connecting the Circuit
The next step is to assemble the simple circuit (pictured in the image below). Take a good look at the breadboard schematic and make sure you have connected the circuit up correctly.
Step 7: Attaching the Bulldog Clip Wire and Making Noise With Your Finger
Take the bulldog clip wire and attach it to your connection pad at the start of your line which you painted earlier. Next take your slider wire and run it along the painted line. By moving the slider across the painted line you can vary the frequency of the sound coming out of the speaker! If you have some copper tape lying around you can stick the exposed metal of your slider wire onto your finger for a more natural interaction with the paint.
Step 8: Completed Circuit!
You can now make some awesome sounds and design even more interesting painted potentiometers too. Try using vinyl cutouts as stencils or even try screen printing if you have access to the equipment. Make sure to send in photos or videos of you having fun with this circuit so we can post it on our community wall.
If you have any questions please email them to firstname.lastname@example.org, and don't forget to submit your own projects to email@example.com