LED Star Pumpkin

Posted by Erin, the RobotGrrl on Friday, October 31st, 2008

I did make something for Hallowe’en… it isn’t much, but it’s just LEDs in a pumpkin in the shape of the star. The most time consuming part was cutting the wires and soldering them… plus, I had to solder a 1K Ohm resistor to each of the positive leads too. Then, I had to shrink wrap it so it wouldn’t short out (like some of the LEDs on BubbleBoy short out because I didn’t shrink wrap them).

It was okay- I wasn’t too pleased with the end result because I didn’t place the points on the star right… and I wanted to carve it out. :/

I knew from the start though that I want to re-use these LEDs, so I have them all connected into a small black box. Inside of the box is an Arduino – a RBBB. On the outside of the box held together by tape is the 9V battery and a latching switch.

The program basically cycles the LEDs like a marquee in HTML, then blinks them “seizingly” fast (LOL).

I think I may put the LEDs up in my window… it might look cool!

Posted in: Art, Projects.

RBBBs and Pololu SSCs

Posted by Erin, the RobotGrrl on Tuesday, August 5th, 2008

I received the two RBBB’s, 1 FTDI TTL USB cable, and two Pololu Serial Servo Controllers (SSC) I bought a few weeks ago. Since then… I’ve been tinkering with them quite a bunch. I learned an incredible amount too from just a tiny board!

Building up the RBBB wasn’t too hard. At first, I printed off the wrong ‘instructions’ – which mind boggled me a bit until I noticed that they were indeed wrong. Once I had the right instructions printed… it was more simple. I was worried about the polarity of the bigger capacitors. After I had it all finished… I went and looked up the FTDI-USB cable specs. This cable is pretty interesting if you think about it, 1 wire turns into 6 more colourful wires -Gnd, CTS (clear to send), +5V, TX, RX, RTS (request to send). I downloaded the Blink program without any problems… until I wanted to test it. The LED wasn’t blinking! After about 5 minutes of intense thought, I realized that there was no LED on pin 13. That was a stupid mistake!

Another stupid mistake, but this one is funnier, was when I was trying to test the other RBBB.
… I forgot to put the chip into the IC socket. =D That really made me ‘lol’ for 10 minutes.

Then, I was trying to fit it into the breadboard… lets just say it took a longer than normal time.

When the Pololu SSCs showed up, I was pretty excited! Then when I saw them… they are REALLY tiny! It was a big challenge to solder these without them flying out of my hand. I don’t have a 3rd hand tool to hold it steady, so I would sometimes have to hold the ‘pinchy-things’ with my elbow and hold the solder and soldering iron with my hands. The headers were extremely difficult too…

Getting the Pololu to work with the Arduino is pretty aggrivating. I think I’m almost there, I just have to switch the input to the logic level side as I was using the RS-232 one. I thought that the Arduino used RS-232 on its TX line, but it doesn’t. It uses a non-inverted logic level (er well, that’s at least what I read). Tomorrow I plan on looking up the difference between the two

Here are some pictures… I finally threw the desoldering pump out the window (joking) and bought solder wick. Also finally bought NON-LEAD SOLDER! =D

Other than playing with these, I’ve been flow-charting A LOT of AI programs, and learning more first-order predicate logic. I really like logic and the probabilities and Bayes and everything!!!!! Also having fun thinking about random and bell curves… More back-dated Stanford blog posts to come (so many photos hahah)!

Posted in: Programming, Projects, Robot.