We're in the depths of winter now, so what better time to mix things up a bit?

Next Wednesday (2/5) we will be having our February meet-up, and for a change of scenery we will be venturing over to the University of New Hampshire in Durham for the evening. We will meet at Kingsbury Hall (details here) which is the home of UNH's engineering programs. 

We will have a simple project on hand and we will also get a chance to explore and see what engineering looks like at UNH. Please note that we be meeting slightly later than the normal time due to UNH parking restrictions, so it's okay if you're late :)

Also, we'll be sharing some exciting news about happenings this spring. If you're on the mailing list, you may have heard the biggest piece of news but stay tuned for more details.

Hope to see you next Wednesday!

- Lindsey
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:
  • Breadboard
  • LED
  • 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!
Lindsey reports:

So today is the day of the Robot Hacks Show & Tell, and I'm not sure if everything will come together quite in time. For the record, I'm totally fine with that and I'm pleased with the progress we have so far.

I'll be meeting up with Alex from Seacoast Makers today and I believe he's making a bot of his own.. so we may have a showdown on our hands!

As of right now, we've got the vibration motor mounted to the milk jug chassis, and it works! But we've still got some issues..
Current issues:
  • The capacitive sensor is acting wonky again. My guess is that having the motor circuit so close to the sensor is causing some kind of interference.
  • No luck so far with programming the motor to spin when the LED is triggered to turn on. It just spins at full speed all the time.. I can connect the motor directly to the LED circuit and it works perfectly fine, but I don't know if that's the best idea..? (Seems too easy.)

Any ideas?

- Lindsey

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. 
Our concept is the "Scaredy Cat" which is a cat that reacts when someone tries to touch it. 
We'd like to build a capacitative sensor our of tinfoil, but our backup plan is a Ping ultrasonic sensor.
A couple possible reactions we're thinking of:
  • Triggering a vibration motor so the cat shakes
  • Red LEDs turn on

Here are a couple sources of inspiration (and code..)
Bare Conductive: Capacitance Sensor 
Arduino CapacitiveSensor 
NOTE: If you try this yourself and you use a laptop, make sure your laptop is plugged in so the sensor is grounded! This was very frustrating but now it works like a charm! :)

Want to join the conversation? Check out the Seacoast Robotics Robot Build group on Facebook.
I've been working my way through this fantastic book, because as you may know, I'm a noob at Arduino.
Up until now, I have used 123D Circuits to virtually simulate the basics of hooking up LEDs and such to a breadboard. This morning, I'm playing with the real thing! 

We have an idea for our Robot Hacks bot, but I've learned over the past few days that a simple modification isn't so simple after all, so I'm going back to the basics...

We'll share what we've got at the November Robo-Meetup tonight. Maybe I will see you there!

- Lindsey

We found out about this awesome opportunity through MAKE to participate in their "Robot Hacks" series, where teams can apply to receive a kit of parts and make something cool. Check out the Robot Hacks community on Google+ to see what other teams are planning.

We put together a team with Alex of Seacoast Makers, and we just got an email that a kit is on its way.
Join us on Facebook and see how you can get involved.

Read Lindsey's thoughts after the jump..