Thursday, January 8, 2009

Second Robot: Tricycle built for Line Followin'

So after Success with the Bumper bug...I read some more in the books and saw what they had to say. I like the Knudsen book best, I think, because it does a good job of getting you active and then explaining higher concepts, behind design and mechanics of building good robots. So in reading some more from it in after building bumper bug, I found that it was repeating some of what I had already read in the introduction of the Baum book. I also looked at the Baum book on what they had to say on building a bumper robot (one that knows to back up and try a different direction). The concepts were pretty close to the same although they had taken a slightly different route making the bumper and also had example code in another programming environment, which I am planning on coming back to for my final project.


I then moved on to building a new robot....which meant that there was some slight sadness as bumper bug had to be dismantled, in order to get the RCX and other parts that I had used on it. I am once again in the Knudsen book, following their building and programming guide

Here is the what I am calling the Tricycle at one of his beginning stages:

He has gotten his free movin' leg attached, but no motors. The white wheel object is part of what was left at the time of bumper bug, it is connected to part of the base that I had taken the RCX unit off of and hadn't need to fully get into other of its parts.


What Tricycle looked like most of the time while being built, flat on his back. Or on the face of the RCX unit. I believe that he is in the same state as the above picture, only in a different angle. On a side note: I would like to bring your attention to the grey tool on the bottom right corner of picture, it is a tool that helps you take a part the lego bricks...Saving my fingers from great pain in the taking a part of creations.


He has now been given his "nose", where the light sensor will go and the motors that will provide the energy/turning motion for his wheels. The light sensor part is how Tricycle will be able to tell if he is on a black line or not.


Here is the finished product of building the Robot. The big wheels are in front of the motors (there is one directly across for the one in the picture). The light sensor is the blue brick. The black bricks on the RCX unit that have wires coming out of them is how the RCX communicates with the Light Sensor and the Motors.

I have started the programming processes for Tricycle in the computer and believe that I am almost done. With this program, Knudsen is directing me through using subroute in the programming in the Lego Environment. He also brought up a point in the programming section on this robot that I would like to mention and that was: you need to prepare for the worst. I think that I already knew this, because part of robotics is the need for the robot to be able to communicate with the world and the world is not a science labitory. So in programming this robot to follow a black line, we can't just assume that if he doesn't sense the line that he needs to turn the opsite way that he did before to find it because the line could be curved. Therefore in this program, we will use a timer in order for the robot to know when he needs to turn the other way to try and find the line again.

Time spent after last time logged: 3 hours
Total for Today: 4 hours 40 minutes
Overall: 14 hours 10 minutes

"Running Robot"

video

So for those of you who hear my voice very softly....I am simply talking to myself in the excitement of seeing the Robot move around or wondering at what it is doing.

The first object that he bumps into is my lunch bag, then he starts to go over to a wall but doesn't bump into it...turns and starts going underneath the table, which I was impressed that it got the right angle to be able to go between the feet. I then stopped the recording because it was headed to feet that it was going to run into and it was going backwards. What you don't get to see before I turned the robot off, was that after trying to push himself backwards, he then changed his direction and tried to go a different way.

I have now worked another 40 minutes for today, bring today's total to 1 hour and 40 minutes.
Overall: 11 hours 10 minutes

Excitement Abounds!!!!!

Great news....the program downloaded...at least everything showed that it downloaded....now to snap the robot's 2 large pieces together and test it out. :-D

Trouble Shooting......With more that should be coming later today....

So I worked for about 30 minutes this morning on trying to figure out what is going on, why I can't get the program to transfer to the RCX. To show some other readers out there, who are not familiar with the set up....


The yellow brick is the RCX unit shown in another the post. The black unit standing up, is the IR transimitter, which is hooked up to the computer. The connection that it uses is a 9-pin serial connection (My guess what be that new models of the Lego Robots are now coming with USB connection....to answer a question of how it connects to the computer....according to the help that is linked in the next paragraph).

In the sense of trying to figure out why stuff won't transfer, I have tried googling the error message and got what I felt was very little help.... Try inserting new batteries into the RCX unit.....So Right now...This is what my "built" robot looks like.....


Two large pieces....because the battery section is on the bottom of the RCX, which makes sense for the buttons need to go on top....but it is a pain to change batteries then once the robot is built.

When that didn't work yesterday, I took books home with me to see if I could figure anything out. While since the message that I was getting was about the IR transmitter, I thought that maybe it some how drained its battery and needed a new one. So that is where I started this morning: Changing the 9 volt battery. I also checked the computer to make sure that the Device Manger was showing the port working (it was) and then told it to check for a new driver update (nothing was out there that was better....according to Windows)

The good news is that I got the IR transmitter to transfer the firmware to the RCX (it had "disappeared" since the batteries must have been out of the RCX unit for longer than a minute). Evidence:


The green light that is showing is blinks and lights up when the IR transmitter is transmitting data.

The numbers keep adding one while the firmware is transferring.

And that is all the farther I have gotten so far, as I had to run and go do something for a couple of hours....I am now back and am going to try to convince the software on the computer, the IR transmitter and the RCX unit to all work together and transfer the program!

Time Worked So far today: 1 hour
Time worked over all: 10 hours 30 minutes

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