First Robot!!

18/12/08

I`ve marked this robot as complete, because it`s in the process of being torn down for parts. It was fun and a good learning experience in electronics and programming.

This is my first robot. I decided to build it after seeing the amazing YDM on Make website :) Really this is just my first robot to get a handle on electronics and programming. It wont do anything except move around and avoid stuff.

It doesn`t do much just yet, still working on programming seperate bits and pieces at a time. Spent AGES trying to get a H bridge working with the L293NE, had to add the extra diodes on the motor lines but it just wouldn`t work! Turned out to be the crappy mini bread board I used. It had a sticky paper backing which I used to stick to the top of the robot but the metal tracks were being pushed OUT THE BOTTOM OF THE BREADBOARD whenever I pushed a lead into it >:(

Physically the robot is made entirely out of some foam board stuff. I dunno what its called really, its like dense packing foam. Its pretty rigid but you can cut it and poke holes in it easy. Its partly black because I recycled it from something else :) 

 Heres the left hand side testing on the H bridge. This is only half of it! Once both sides are tested ill solder it up onto something..

 Also on the other end of the board you can see the IR reciever which came from an old sony DVD player. I`m going to use the remote to drive it in manual mode. 

Eventually the robot will also have an autonomous mode so it can just trundle around the house getting under my wifes feet probably :)

Cause I live in Japan and robotics stuff here cost a billion dollars for ANYTHING (except the sharp IR which I found a shop here sells for about $7.50 (cheap!) im gonna try out the visible light detector Frits is working on. It looks so cool Frits "Im discobot and here I come with my green lights!" hehehe.

 The IR remote, sharp IR sensor and H bridge all work and I have tested them seperately. Still need to make code for the servo.

Updates later!

 I`ve been working on the robot a bit. Made up a small circuit board with H bridge, logic and output pin headers and power as well from the 5x NiMH batteries and from the arduino. Also I wanted the robot to communicate through roboty-like beeps and an LED in his mouth so I put pins for those too.

There is tons of space left on the perf board for something else if anyone has some suggestions?

I`ve got some cable connectors that suit the pins I put on the board on order but they havent arrived yet :( so until they do everything is just pushed into little bits of cut insulation. you can see it all there. Not great but it works :D

Another shot of the dodgy connections.

 The little blue pot at the back there is going to help me trim the voltage divider for my battery checking circuit I found here http://www.societyofrobots.com/schematics_batterymonitor.shtml. 

I fixed up the top deck making it wider and much more sturdy plus gave it a bit of the paintbrush treatment :)

The 3 holes in the front plate is my "FritsLDR"!! Its just a giant tricolour LED and 2 LDRs in black tubes.

Tried some simple code reading each LDR 20 times with the LED on and 20 times off then outputting the difference. It works ok but the 2 LDrs must be crooked because they give wildly different readings, plus its affected by sunlight a fair bit. Still, flashing colours is super cool :) I might end up facing it down as an edge detector instead.

The IR sensor has such a narrow cone of view it has to take a reading every 15 degrees from right to left which makes his head twitch like crazy. As you can see in the video he STILL tries to climb walls now and then :@

Still working on the code. Right now its pretty shit. I can use the dvd remote to put it in manual mode, autonomous, or make it run the auto block once just for testing.