3-28-2012

Today in class we had the majority of the time to work on getting our line followers and inferred senors to work.  Towards the end of the class I manged to get my robot to follow the line, but there were a few things that need fine tuned.  Most of the class needed more time to work, so on Monday we will have some time to work more.  Hopefully I will be able to get the robot to run smoothly and do an official test run.

3-26-2012

Today we used the beginning of class to go over case statements to use in our program and went over everything we will need to have in our program to use the line followers and inferred sensor.  I finished mounting the line followers and inferred sensor to the body of the robot, then began working on writing the program.  I wasn't able to finish and will have to work on it next class.

Front view of mounted line followers and inferred sensor

3-21-2012

Today in class we spent about half of the time talking about batteries.  We learned how they can be categorized, such by voltage, chemical makeup, configuration of cells and a few other ways.  we learned how to calculate voltage and capacity of batteries if their cells are in either series or parallel.  We talked about the discharge rate and how that effects battery life.  We also learned about some characteristics of the different chemicals used in batteries, and that some chemicals allowed batteries to be recharged as well as have what is called memory effect, which occurs if you recharge some batteries before they are drained, which shortens their life.  After we finished talking about batteries we went on to how we were going to wire in our line follower sensors.  For the rest of the class time we wired in the line followers and wrote a short program so we could test them to make sure they worked.  I wired in the sensors but I didn't attach to bracket that holds the sensors in place below the robot yet.

Side view of robot

Top view of senors wired in

Front view

3-19-2012

Today in class we learned about inferred sensors and their uses.  They are used to detect distances and give feedback.  We were each given an inferred sensor to connect to our robot.  We wired them onto our robots and then wrote a simple program that would have the sensor detect a distance and then display it in a window in the Picaxe program while the robot was still plugged in.  But the numbers it would display were not in inches or centimeters, so we had to figure out a formula that would give us the correct number, which I didn't finish before the end of class.  But after a while we moved on to the line follower sensors that were in our kits and talked about how we were going to install them in our robots.  You can see in the pictures below the steps I took in preparing the senors. First I trimmed the leads of the sensors so they were a little easier to work with.  Then I soldered pieces of wire onto the end of each lead.  After that I put heat shrink over each of the solder joints to prevent them from contacting each other and to strengthen the joint.  Next I put pin crimps one the other end of the wires so they can be easily plugged into the board.  Last, I put pairs of the crimped end into sleeves to keep them organized and make plugging them in easier.

Inferred sensor

Line Follower sensors

Sensor with trimmed leads and wired soldered on

All three sensors with wires soldered on

Heat shrink put over the solder joints

Crimps put on to other end of wires

All the crimps put on

Crimped end put into sleeves

Finished sensors

3/7/2012

In class today we spent the majority of the time discussing sensors.  We went over the different types of senors, analog and digital and the different kinds of sensors that fall into those categories, such as inductive, capacitive, optical, thermistors, light sensors, and line followers.  We went over the different ways that sensors can be categorized, such as contact and non-contact, active and passive, temperature, position, and load.  The we talked about how we would need to wire sensors onto our board using the Picaxe as well as things we could do within the program that will help us in the future when we start to use senors move heavily.  Then we were given two Bumper Switches to wire onto our boards.  Then in Picaxe we wrote a program that would display in words something to the effect of "the switch is pressed" in a window on our laptops when the switches had been pressed.  We learned to use binary that corresponds with ports on our board to make it easier to program AND statements and also how to use a mask in case we have other inputs in a port that aren't sensors or are different sensors.

Front view of the Bumper Switches

Side view of the Bumper Switches wired in.

3/5/2012

Today in class we were given a task to work on for the duration of the class time.  Our task was to complete seven straight sections of the maze we used in previous assignments.  But to make it different for each student we were each given an intersection of the maze to start at and if two students started at the same intersection, one went towards the Start of the maze and one towards the Finish.  So, a student might start in the middle and go towards the Finish, but it might only take four straight sections to reach the Finish, so the robot would have to turn around and complete two more sections.  We were allowed to use speed control if we wanted but it wasn't required.  We also had to have the robots make the turns by pivoting with both wheels, in order to demonstrate that we could program the wheels to go backwards, instead of making of turn with one wheel turning and one stationary.  My robot was able to complete the sections with a few minor manual corrections during the run.  Dr. Bronakowski said that was fine and I received credit.  I unfortunately forgot to take video of my robot during the run.

2/29/2012

Today in we went over the uses for the L293 driver.  The L293 will allow us to have directional control over our motors in our robots.  We then wired our robots to just test the directional control not using the micro controller.  Mine worked when I switched the wires on the L293.  Then we wired in the micro controller with the L293 so we could have speed control.

View of the final wiring

Top view of the robot wired up

 

The above video shows the robot going back and forth and making turns using directional control