Ideas for RobotC articles

VEX V5 General Discussion General Forum
1

//I noticed that this message was not in the recent posts list so reposted it here.

Hi

On our website we are making a page with lots of tips for building/programming/competing with vex robotics.

I want to write a few short articles on how to do certain things with RobotC
I have already written an article titled “Line Following with RobotC” (Not finished)

Has anybody got any ideas on other subjects you would like me to write about?

Thanks

2

The following concepts might make good educational examples:
7 line holonomic drive using trinary range limiters:
joy_1_x = vexrx(1,1) - 127;
joy_1_y = vexrx(1,2) - 127;
joy_r = -vexrx(1,2) ; // swap +/-, no 127 offset
pwm(1, x = joy_1_y - joy_1_x + joy_r > 255 ? 255 : x<0?0:x);
pwm(2, x = -joy_1_y - joy_1_x + joy_r > 255 ? 255 : x<0?0:x);
pwm(3, x = -joy_1_y + joy_1_x + joy_r > 255 ? 255 : x<0?0:x);
pwm(4, x = joy_1_y + joy_1_x + joy_r > 255 ? 255 : x<0?0:x);

Other types of driver operator assist code:

  • deadband input
  • parabolic input scaling
  • jog-mode for creeping forward slowly and precisely
  • axle-twist detector (using two potentiometers)
  • Raise arm to specific height (using one pot)
  • Raising arm to several different specific heights(using one pot)
  • Using a push button and one pot to set limits for several arm heights.

All kinds of autonomous behavior;

  • you already have line follower,
  • gradual accel/decel programming for specific distance using optical encoder
  • specific rotation using compass sensor or accellerometer or gyro
  • re-square yourself against back wall , using two corner bumper switches
  • example catapult code statemachine:
    • lower arm until limit switch, set trigger, raise arm (repeat if limit sw breaks), wait until trigger button to release trigger

Uniquely RobotC features:

  • Uses for multiple co-routines
  • speed, reaction-time, performance mistakes to avoid
  • use of large lookup tables instead of functions

It makes articles more interesting if you have a frame work of a competition that other people are familiar with, such as current or past Vex competitions.