Lindsey won't be making it to the meet-up tonight. Have fun tonight!
Part 1. Constructing the Sensor
The sensor itself is really easy and quick to make. To make the sensor work, you will need access to an Arduino, a breadboard and some basic electronics components.
To make the sensor into an ornament, simply run some ribbon or string through the metal loop at the top.
Part 2. Building the Circuit
This is a simple circuit that requires a few basic electronics components:
- Jumper wires
- 10 Mohm resistor (or any similarly high value resistor)
- Jumper wire with alligator clip terminal
Use the diagrams below to guide you in building the circuit.
Part 3. Programming the Arduino & Testing!
This is assuming you already have the Arduino software.
1) Download the CapacitiveSense (CapSense) Library here.
Follow the directions to make sure it installs correctly.
2) Create a new sketch. Copy and paste the code below into your sketch. Verify and upload to your Arduino.
(Note: The most common error we had was getting the name of the library wrong, but hopefully you won't have that problem.)
3) Clip your sensor to the alligator clip and test it out!
I found a cat puppet that I made a while back and it looks like a great candidate for our Scaredy Cat's body! I found some fabric to make a simple sensor, and you can see it being modeled below.
It's taken a while to get the sensor actually mounted on the cat's head because I needed to buy myself a new glue gun after my old one shorted out. (That was a bit frightening!)
It's cool to see the robot coming together, but there are still some significant challenges at this point..
1) Do we want to include two sensors to trigger two different effects? How can we program that?
2) Can we trigger multiple effects (two LEDs & vibration motor) off of one sensor? How can we modify the circuit to make everything work? (In particular, we have one DC motor that would be fantastic but it doesn't run off of the 5 volts from the Arduino, so..)
These are pretty basic questions, and I know there are solutions out there. It's just a matter of finding the answers and learning more.
Got any ideas? Want to drop some knowledge? Tell us about it in the comments.
We unveiled the Robot Hacks project at our Seacoast Robotics meet-up last week, and much of the time was spent trying to figure out how to make a tinfoil capacitive sensor work. We had no luck that night and we've been troubleshooting for the past few days, but we're slowly figuring all of this stuff out.
This evening, I rigged up a capacitive sensor and ran a program that triggered a touch to turn on an LED. The LED in this video is on the Arduino board, but it's pretty hard to miss. This means we're one step closer to creating our angry robot cat that does NOT want to be touched!
What I really love about this process is how the challenge keeps drawing me back and I keep learning so much more. The problems that I saw a week ago are gradually unraveling themselves as I am getting more familiar with how things work.