Archive for March, 2008
I looked everywhere in my stuff to find a gold or aerogel capacitor. Looks like I don’t have any left. And it was the middle of the night. What would you expect me to do?
Yes, I have parallel connected 12x 4700uF (and 1x 3300 in addition) capacitor to run this monster.
It has a simple 1381 solarengine. The special thing about this is I have made my own gear system to run it on problematic surfaces. It works pretty well. Charges for about 15 seconds under direct sunlight and runs about 15-20 cm at once.
I have built this one for my girl friend. I am a geek after all.
Well I got sick of trying to build bodies for robots from nothing. So I bought a small toy truck. And built a robot over it. This is the most successful one that I have built so far. It has touch sensors both in front and back. Which lets it reverse to get away from obstacles. And has a light seeking behavior which lets it finds the place in the house where people are hanging at that moment. (room with people = lights open, room without people = lights off).
I have built it as optimized as possible. It runs for about 3 days with duracells. It runs with my humongous 3000 ma nimh batteries for a week before he needs a recharge! The sensors lets him hang around the house without getting stuck. And the hardcore GM2 gearmotors I bought from solarbotics.com helps him to pass over any small obstacle such as cables and funky carpet edges.
I will soon post the circuit and video. It is based on the classic herbie circuit with LM386 but it is modified for the reverse function.
Here is the circuit. The small chip (LM386) is for light seeking. The bigger one (74HC14) lets him reverse and control the information leds. The green led is the charge indicator and the red one flashes while the robot is reversing. The capacitors over there are the reverse caps. And the trimpot on the middle is for adjusting the motor speeds.
I love these GM2 engines.
These are the front sensors, made with tiny buttons.
As a software developer, I thought it would be good if I take some time off of hardware development and I have started a software based robotics project. I had a few robosapiens and decided to make them play soccer. I have programmed a software which uses a camera at the top of the field, calculates the coordinate and angle of the robot, calculates the coordinate of the ball and commands the robot to the ball, step by step.
Here are the photos from the test runs.
I have bought 2 cheap walkmans, took off the gears and motors and made 2 gear motors to power a bigger robot. This one is a robot with 4 stacked 74HC240 chips. It has 2 feelers which lets him avoid obstacles and 2 IR photodiode eyes to follow the light source. I will prepare and post the circuit soon.
I did not get satisfied with the previous Small Fella I made. This one works much better, and much smaller. A 555 photovore circuit is used. And I have made a case for 6V small batteries to power the bot. The capacitors have no function, they are for balancing the bot as it was falling without them. I have built 2 versions of it, here are the photos.
This one is much more balanced, since the motors are on the back.
I was doing lots of 1381 solarengine, and since the 1381 can’t be found in local electronic shops here, I decided to build a fled one. I have picked the FRED circuit, as it is the one with the highest performance among the fled engines.
I have bought 2x 1.5 v solar cells. (as you need minimum 3V to run a solarengine)
2 little pager motors at the end of the back legs are used as the muscles.
The 2 red fled (this is why the circuit is called Fred =) ) are the eyes and the voltage pumpers of the solarengine.
Here is the result;
Isn’t it cute? ^_^
This one is a kit from solarbotics.com. I bought it to practice. It is a quite complicated one for beginners, yet it works great if you solder it right. It calculates where the light comes and goes there precisely. I recommend you to build a few kits before starting building your own beambots.
A really old solarbot of mine. Made out of two classic 1381 solarengine, and 2 cross solar panel, this bot has a behavior on going to the brightest light source in order to feed himself.
It is made out of %70 from broken electronics and plastic parts.
Only the panasonic 1381 voltage triggers and solarpanels are new.
Here is the circuit used. (circuit images are taken from solarbotics.net)
You can find the 1381 voltage triggers from www.solarbotics.com (do not search this part from your local electronic shops. You won’t be able to find it. If you don’t want to wait, just build a FLED solarengine instead.)