Swatching for a Robot
January 9th, 2006 at 8:19 am (uncategorized)
When you build something made up of electrical parts, it’s a good idea to test out the configuration before you commit to putting them together permanently. You can sometimes take them apart after they are put together, but it’s a pain, and better overall to not have to do it very often.
So here’s my version of a robot swatch (click for super high resolution version):
To trace the path of the circuit, we start with the battery. It goes through one of the red posts (red means HOT, don’t touch, there’s current going through here) & into the red button on the right. No, it’s not a "big red button" but it was all I could find that fit into the holes on the breadboard. If the switch is in the "on" position, the current will travel down to the red LED on the bottom right of the circuit. When that red LED is on, it means there is power going to everything hooked up into the board. (This was not my idea, but it is a good idea. it’s in the book I got http://robotroom.com).
So now there’s a power bus on the board that is ON, (assuming we’ve pushed the button and our red LED is lit). The whole point of this circuit is to decide if there is more light on the right or left, so the robot (yeah, this is a robot - couldn’t you tell??) can decide to turn left or right based on where the line it’s following is.
The Green and Yellow LEDs in the middle (pointed to by the "Decision Indicators" text/arrow), are what tells us which side is brighter. The photoresistors that sit between the yellow/green LEDs and the red power-on LED on the right are detecting how much light is in the room. They change the value of resistance based on the ambient light. It’s harder to see, but there are also headlights in that area - bright white LEDs that will help light the way. The chip in the middle tests the voltage and tells the green or yellow LED to light up.
The stuff on the left side (with one red LED) I’m still working on. There’s a way to amplify the voltage (or current? I always get that mixed up) so that you can light more than one LED in a row. When the robot is done, it’ll have three yellow lights all along one side, and three green lights on the other side. You can watch the robot ‘think’ by seeing which sets of lights are on. Plus blinking lights always make it look cooler!
marta said,
January 9th, 2006 at 7:58 pm
holy crap, robot head! Nancy, you have knitting nerds to a whole new level. I am in awe.
marta said,
January 9th, 2006 at 8:02 pm
oops, that should read “…’raised’ knitting ‘k’nerds…”
how un-knerdly of me to get it wrong!
Joann said,
January 10th, 2006 at 8:32 am
You are SUCH a geek!! :P Then again, my dad self-taught himself electronics and I was able to follow your circuit description, nodding my head at the “red is hot” info. Hee hee…
Ingrid said,
January 23rd, 2006 at 12:43 pm
Yeah, yeah, but when does it make your test swatch and tell you what needles you need to buy for perfect gauge?! ;)