Ultrasonic Rangefinder

An ultrasonic range finder sensor enables a robot to detect obstacles in its path by utilizing the propagation of high-frequency sound waves. The sensor emits a 40kHz sound wave, which bounces off a reflective surface and returns to the sensor. Then, using the amount of time it takes for the wave to return to the sensor, the distance to the object can be computed.

The sensor can be used to determine distances to objects. It can be used as a tool to determine if any objects are in the robot’s path at all. To increase the sensing range, the sensor can be mounted to a servo to allow it to rotate. The following are some basic information to help you kick off your project. 

Documentation: http://www.vexforum.com/wiki/index.php/Ultrasonic_Range_Finder

Instruction: http://content.vexrobotics.com/docs/instructions/276-2155-instr-0312.pdf
Video: http://www.education.rec.ri.cmu.edu/products/teaching_robotc_cortex/
then click Sensing and select Forward until Near.

Line Tracking

Line tracking is an easy way to make your robot autonomous. In order to follow the dark-tape marked path on the floor, you have to install the line tracker in front of your robot, and program your robot accordingly. The following are some basic information to help you kick off your project. 

Documentation: http://www.vexforum.com/wiki/index.php/Line_Follower

Instruction: https://docs.google.com/file/d/0B4er4OWY8aPMazZBNnJwUVFSN3c/edit?usp=sharing

Video: http://www.education.rec.ri.cmu.edu/products/teaching_robotc_cortex/
then click Sensing and select Line following.

Using the VEX Cortex with ROBOTC

Once you finished building your Clawbot, you are ready to setup the programming environment such that you can start program your robot. The following important document will help you set up the communication between your laptop and your Cortex microcontroller such that your group can formally kick off the programming project.

Using the VEX Cortex with ROBOTC

Engineering Notebook

Project groups are required to maintain daily online logs about their progress. The writing should be clear and concise. The following list is a template for your logs.

• Progress: tasks accomplished, problems solved, questions answered, lessons learned, new idea identified, etc.
• Problem: difficulties encountered, missing information, equipments required, materials missed, open issues, new risks or show stopper identified, etc.
• Plan: steps to attack the problems, action items for tomorrow, experiments to conduct, ideas to try, etc.

Restore a Vex PIC Microcontroller

Right after you finish building your tumbler, you may notice that your robot behave weird and run by itself randomly. It maybe caused by some program downloaded to your PIC Microcontroller last year. So, you need to restore your Microcontroller back to its factory setting. Go to the following link: http://www.vexforum.com/wiki/index.php/Software_Downloads, and find the PIC Microcontroller Downloads section. Then, you can follow the instructions and restore your Microcontroller.