1. ROBOTC for VEX On-Site Professional Development

2. Advanced Remote Control

3. Advanced Remote Control
More loop control please?
Is remote controlling the robot forever always appropriate?
Next Challenge: Mine Removal Challenge
Question: Where would the wait statement go if we wanted the robot to be remote controlled for a controlled amount of time?
Answer: Nowhere! We need something else.
Solution: Timers
Can be thought of as internal stopwatches (4 available)
Like encoders, timers should be “cleared” anytime before they are used
Watch where you clear them!

4. Timers

5. Advanced Remote Control
Wasting Time?
The time it takes to turn on the VEX and get situated could be used to score points, but is wasted.
Could we make the robot wait to start it’s timer until we were ready? Any ideas?
Wait for a Remote Control Button press
The robot won’t start the timer until we say so
The robot also can’t move until we says so
Program Flow Trace
Could this idea also be used to make a “more friendly” start button on a non-radio controlled robot?
Other ideas of how to improve remote control?
Use the buttons to initiate common actions
Turn 90 degrees, move straight forward, ect

6. Advanced Remote Control
Use the buttons to control the arm
The VEXnet Remote Control buttons send values of 0 or 1

7. Sensing

8. Sensor Information: Touch Sensors

9. Touch Sensors Touch Sensor Check How they work Setting them up
Limit Switch plugged into Digital Port 6
Bumper Switch plugged into Digital Port 11
How they work
Digital sensor - Pressed or Released
Watch out for “bouncing”
Setting them up
ROBOTC Motors and Sensors Setup window
Using them
The SensorValue[] command

10. Move Forward until Pressed

11. Touch Sensors Start Button
Remember how we used the Remote Control button to start the timer portion of the program. How would we implement the same thing with the bumper switch?

12. Sensor Information: Potentiometer

13. Potentiometers Potentiometer Check How they work Setting them up
Plugged into Analog Port 3
How they work
Analog sensor
Measures absolute rotation of a shaft between 0 and ~265 degrees
Returns values 0 – ~4095
Internal mechanical stops
Setting them up
ROBOTC Motors and Sensors Setup window
Using Analog and Digital Sensors
Using them
The SensorValue[] command

14. Potentiometers

15. Advanced Arm Control

16. Sensor Information Ultrasonic Rangefinder

17. The Ultrasonic Rangefinder
Ultrasonic Rangefinder Check
Input wire plugged into Digital Port 8
Output wire plugged into Digital Port 9
How they work
Similar to how bats and submarines work
Digital sensor – but returns distance values in inches, centimeters, or millimeters on the Cortex
Setting them up
ROBOTC Motors and Sensors Setup window
Using them
Be careful not to use them immediately as your program starts – they take time to initialize and will return negative values
The SensorValue[] command

18. Ultrasonic Rangefinder
Other Properties
The Ultrasonic Rangefinder is able to detect objects in a “cone” field of view. As objects get further away, the sensor is able to detect them further away from the center of the sensor.
The sensor bases distance calculations off of sound waves, which means that some objects may not be detectable: soft objects that absorb sound, sharp objects that deflect sound, etc.
Do not use the ultrasonic sensor as the very first command in your code. Until the first sound echo returns to the sensor, it will have a value of -1. A simple delay at the beginning of your program solves this.

19. Forward until Near

20. The Ultrasonic Rangefinder
Forward until Near
Move forward until the robot is “near” an object, then stop
Automatic Pick-up
Straight Forward until Near + picking up the mine
Optional: Assign to a button on the Remote Control

21. The Ultrasonic Rangefinder
Forward/Straight until Near
Move straight forward until the robot is near an object, then stop
Follow along with videos in VCVT
Automatic Pick-up
Straight Forward until Near + picking up the mine
Optional: Assign to a button on the Remote Control

22. VEX Robotics Competition Programming

23. VEX Robotics Competitions
Official VEX Competitions utilize special Field Control Hardware to enable and disable robots

24. Competition Templates
ROBOTC is fully legal in VEX Competitions
You must program using the built-in templates
Competition Template
Driver Skills Template

25. Competition Template
Pre-autonomous code goes here – clear encoders, ect
Autonomous code goes here
Remote Control code goes here

26. Testing Competition Code
The ROBOTC Competition Control Debug Window simulates the Field Control Hardware, so you can test your code

27. Additional Sensors

28. Sensor Activities Finish the Automatic Pickup Behavior
Add code to automatically score the ball
Quick-Tap Challenge
Review Sensing Videos
With a Virtual Robot:
Sensing > Robocci
Sensing > Speed of Sound
Sensing > Robo-Dunk 2