Changes between Version 15 and Version 16 of ControlSystems/SoftwareTeam/Training/GettingStarted/IntroRobotJava

Timestamp:

Oct 16, 2019, 12:44:06 AM (6 years ago)

Author:

David Albert

Comment:

--

ControlSystems/SoftwareTeam/Training/GettingStarted/IntroRobotJava

@@ -53 +53 @@
 * Even though the program is running on the robot, you can set breakpoints, step through code, examine and change variables, etc. from your laptop.
 
+* Extra credit: extend the program to print a message or display a value on the Smart Dashboard when a button is pressed on the xbox controller.
+
 == Second program: Ultrasonic Rangefinder
+
+Robots often need to sense the environment around them, particularly when driving autonomously.  Ultrasonic sensors are like the sonar used by bats.  They emit a chirp of sound and measure the time it takes to hear an echo of that chirp.  The longer the time, the further the sound traveled.  Since sound travels at a particular speed through air, we can use the echo delay to calculate how far away the object was that reflected the sound.  You can read more about ultrasonic sensors [https://wpilib.screenstepslive.com/s/currentCS/m/java/l/599715-ultrasonic-sensors-measuring-robot-distance-to-a-surface here]
 
 Create another program using the !TimedRobot java template and name it !UltrasonicTest. Modify the generated code as follows:
@@ -72 +76 @@
 Run the program and observe the "Front range" value in the [https://wpilib.screenstepslive.com/s/currentCS/m/java/l/599724-displaying-data-on-the-ds-dashboard-overview Smart Dashboard] as you move the robot towards and away from the wall.
 
+Notice that the measurements aren't always perfect; the sensor may receive echos from multiple surfaces.
+
 == Third program: Servo Motor Control
+
+Robots must be able to interact with the environment around them too.  Many types of actuators are used in FRC robotics; one of them is the [https://wpilib.screenstepslive.com/s/currentCS/m/java/l/599703-repeatable-low-power-movement-controlling-servos-with-wpilib Servo Motor].  A servo motor is a special type of motor that can rotate to a precise position, usually between 0 and 180 degrees.  They come in a variety of sizes and strengths.  You can connect a servo motor to any of the PWM ports on the !RoboRIO.  Examine the PWM ports and identify which row of pins are ground ([[Image(https://incompliancemag.com/wp-content/uploads/2012/01/1201_OnYourMark_5019.png, 50px)]], +6V, and Signal (S).  Make sure you connect them to the proper pins on the Servo motor: black or brown goes to Ground, red or orange goes to +6V, yellow/white/blue goes to Signal.  You can read more about servo motors [https://learn.sparkfun.com/tutorials/servo-trigger-hookup-guide/all here]
 
 Create another program using the !TimedRobot java template and name it !ServoTest. Modify the generated code as follows:
@@ -104 +112 @@
 
 Connect a Servo motor to PWM port 1 on the roboRIO and run your program.  You'll need to press the Enable button on the driver station to put the robot in Teleop mode so that teleopPeriodic() is called repeatedly.
+
+* Extra credit: use buttons on the Xbox controller to set the servo to a specific position (e.g. 45-degrees, 90-degrees, 135-degrees).
 
 == Fourth program: DC Motor Control