Weston Schreiber & Joshua Gabrielse Robotics Summer Training Programming #1: EasyC Basics

Weston Schreiber & Joshua Gabrielse Objectives: Understand the 3 stages to programming Program a robot with custom controls Build & Download program to a robot Drive your robot!

Weston Schreiber & Joshua Gabrielse 1 st Rule of Programming Computers are stupid!!!! They do EXACTLY what they are told, nothing less, nothing more, and they never get the idea.

Weston Schreiber & Joshua Gabrielse Flowcharts (lists of instructions) BEGIN END 1.Put instructions on the flowchart. 2.The computer (or robot) will start at the beginning and move to the next instruction. 3.When that instruction is complete it moves to the next instruction. 4.When it gets to the end it keeps doing whatever it was last told to do.

Weston Schreiber & Joshua Gabrielse Break up into groups. Make a flowchart to make me walk out the door! BEGIN END I will act like a computer (it comes naturally) Computers do EXACTLY what they are told, nothing less, nothing more, and they never get the idea.

Weston Schreiber & Joshua Gabrielse Stage 1: Planning (Algorithm, Flowchart, Pseudocode) Stage 2: Coding (Variables, Functions, if statements, Loops) Stage 3: Error Analysis (Syntax Errors, Logic Errors, Readdress Plan) Stage 1: Planning (Algorithm, Flowchart, Pseudocode)

Weston Schreiber & Joshua Gabrielse Flowcharts & Algorithm Planning Two Types of Parts to a Programming Flowchart: Actions Decisions “Yes” “No” Robotics Examples “Turn on wheel motors”“Is the front bumper pushed?” “Lift Gripper Arm”“Has the robot turned 3 times?” “Stop all motors”“Has the encoder registered over 1000 counts?”

Weston Schreiber & Joshua Gabrielse Flowcharts & Algorithm Planning Practice With Decision (Condition) Statements in Flowcharts: Use a set of decision statements that allow the user to pick what movie they will go see: Prometheus (action, sci-fi) Madagascar 3 (comedy, kids movie)

Weston Schreiber & Joshua Gabrielse Writing Your 1 st Program 1.Write a Plan for your Controller Setup 2.Start a New Program 3.Operator Control 4.Build & Download to Robot 5.Autonomous (next session)

Weston Schreiber & Joshua Gabrielse Type in descriptions of what you’re going to plug into each port.

Weston Schreiber & Joshua Gabrielse Type in descriptions of what you’re going to plug into each port.

Weston Schreiber & Joshua Gabrielse 8 channels: 1.x-axis of right joystick (-127 to +127) 2.y-axis of right joystick (-127 to +127) 3.y-axis of left joystick (-127 to +127) 4.x-axis of left joystick (-127 to +127) 5.left trigger buttons Up (0 or 1) Down (0 or 1) 6.right trigger buttons Up (0 or 1) Down (0 or 1) 7.left buttons Up (0 or 1) Down (0 or 1) Left (0 or 1) Right (0 or 1) 8.right buttons Up (0 or 1) Down (0 or 1) Left (0 or 1) Right (0 or 1) VEXnet Joystick ↑ Top View ↑ ↓ Front View ↓ ↑ Front View ↑

Weston Schreiber & Joshua Gabrielse Stage 1: Planning (Algorithm, Flowchart, Pseudocode) Stage 2: Coding (Variables, Functions, if statements, Loops) Stage 3: Error Analysis (Syntax Errors, Logic Errors, Readdress Plan)

Weston Schreiber & Joshua Gabrielse EasyC Built-In Functions: EasyC gives us functions to interact with the basic parts of the robot: Motor Servo Various Sensors (not this summer)

Weston Schreiber & Joshua Gabrielse Anatomy of Functions Name (case sensitive) Parameters (in order) Return Value (not necessary) Description (just for programmer) FunctionName( param, param, param, etc. ) Examples: RectangleArea( width, length ) DrawCircle( radius, centerX, centerY )

Weston Schreiber & Joshua Gabrielse Anatomy of Functions RectangleArea( width, length ) Name: RectangleArea Parameters: width, length Description: Calculates a rectangle’s area Return Value? Area of the Rectangle DrawCircle( radius, centerX, centerY ) Name: DrawCircle Parameters: radius, centerX, centerY Description: Return Value? No return (void)

Weston Schreiber & Joshua Gabrielse Writing Your 1 st Program 1.Write a Plan for your Controller Setup 2.Start a New Program 3.Operator Control 4.Build & Download to Robot 5.Autonomous (next session)

Weston Schreiber & Joshua Gabrielse Starting a New Program

Weston Schreiber & Joshua Gabrielse Start a New Competition Project

Weston Schreiber & Joshua Gabrielse Select Field Control Competition Project

Weston Schreiber & Joshua Gabrielse Competition Projects Initialize: This function runs when the robot is first turned on. All the motor outputs are disabled so the robot can’t move. Use to calibrate sensors. Autonomous: This function runs after Initialize. This runs for fifteen seconds and input from joysticks is disabled. Operator Control: This program runs after Autonomous. All inputs and outputs are enabled. Click the tabs to access the functions.

Weston Schreiber & Joshua Gabrielse Competition Switches Enable/Disable & Autonomous/Operator Control Hardware: plug the ethernet cable into the competition port on the joystick Software: the computer has to be connected directly to the robot controller or through VEXnet from the joystick (via the programming port)

Weston Schreiber & Joshua Gabrielse Example Operator Control Code Configuring the Controller

Weston Schreiber & Joshua Gabrielse Select the Controller Configuration (F5)

Weston Schreiber & Joshua Gabrielse Type in descriptions of what you’re going to plug into each port.

Weston Schreiber & Joshua Gabrielse Type in descriptions of what you’re going to plug into each port.

Weston Schreiber & Joshua Gabrielse Select the OperatorControl tab.

Weston Schreiber & Joshua Gabrielse Put all control code inside the while loop.

Weston Schreiber & Joshua Gabrielse Expand Joystick

Weston Schreiber & Joshua Gabrielse Pick Tank or Arcade mode. Modes Arcade = 1 joystick drive (simpler) Tank = 2 joystick drive (better control) The number of motors should match your robot (2 for the CrabBot).

Weston Schreiber & Joshua Gabrielse Drag Tank – 2 motor onto the flow chart. Modes I will use Tank – 2 motor since driving with two joysticks gives the driver more control. You can use Arcade – 2 motor if you prefer to drive with one joystick.

Weston Schreiber & Joshua Gabrielse Drag Tank – 2 motor into the WHILE loop. WHILE Loops Any statement placed in a while loop will execute over and over again (if the expression equals 1). We drag the joystick block into the while loop so the program will get commands from the joystick over and over again.

Weston Schreiber & Joshua Gabrielse For Tank drive set the Left Channel to 3 (the y-axis of your left joystick) Tank Drive The y-axis of the left joystick should control the left wheels and the y- axis of the right joystick should control the right wheels.

Weston Schreiber & Joshua Gabrielse For Tank drive set the Right Channel to 2 (the y-axis of your right joystick) Tank Drive The y-axis of the left joystick should control the left wheels and the y- axis of the right joystick should control the right wheels.

Weston Schreiber & Joshua Gabrielse For Arcade set the Forward/Reverse Channel to 2 (the y-axis of the right joystick). Arcade Drive The y-axis of your right joystick (if you’re right-handed) should control the speed (forward/reverse) of the robot.

Weston Schreiber & Joshua Gabrielse For Arcade set the Rotate Channel to 1 (the x-axis of the right joystick). Arcade Drive The x-axis of your right joystick (if you’re right-handed) should control the rotation (turning) of the robot.

Weston Schreiber & Joshua Gabrielse Select the motor number for your Left Motor. Motor Numbers The number of the slot/port on the robot controller that a motor is plugged into is its Motor Number. Labels from the Controller Configuration automatically appear in green.

Weston Schreiber & Joshua Gabrielse Select the motor number for your Right Motor. Motor Numbers The number of the slot/port on the robot controller that a motor is plugged into is its Motor Number. Labels from the Controller Configuration automatically appear in green.

Weston Schreiber & Joshua Gabrielse Arm

Weston Schreiber & Joshua Gabrielse Arm Motor Selection Change Joystick # to 2 for the partner joystick.

Weston Schreiber & Joshua Gabrielse Arm Motor Selection

Weston Schreiber & Joshua Gabrielse Gripper

Weston Schreiber & Joshua Gabrielse Gripper

Weston Schreiber & Joshua Gabrielse That’s it for Operator Control Congratulations!

Weston Schreiber & Joshua Gabrielse Stage 1: Planning (Algorithm, Flowchart, Pseudocode) Stage 2: Coding (Variables, Functions, if statements, Loops) Stage 3: Error Analysis (Syntax Errors, Logic Errors, Readdress Plan)

Weston Schreiber & Joshua Gabrielse Build & Download Build & Download your program.

Weston Schreiber & Joshua Gabrielse Download Code to Robot Build & Download your program.

Weston Schreiber & Joshua Gabrielse Erasing & Writing New Code Your program is finished downloading when the bar goes down (erases old code) and goes back again (loads new code).

Weston Schreiber & Joshua Gabrielse Save Save your program even if it didn’t work.

Weston Schreiber & Joshua Gabrielse The ROBOT light should be green (charged battery). The VEXnet light should be green (connected). “My code won’t download!” (Is your robot on?) Make sure to turn your joystick on too. The POWER switch should be ON.

Weston Schreiber & Joshua Gabrielse What color is the ROBOT light on the controller? “My code won’t download!” (Did you use a fresh battery?) green: okay battery red: dead battery

Weston Schreiber & Joshua Gabrielse The USB A-A cable should be plugged into the robot controller in the USB port where the VEXnet key normally plugs in. The other end of the USB A-A cable should be plugged into a USB port on the computer. “My code won’t download!” (Is the robot connected to the computer?) USB A-A cable computer joystick remove the VEXnet key robot controller

Weston Schreiber & Joshua Gabrielse “My robot doesn’t drive right!” (Are the motors plugged in correctly?) Everything should be plugged in according to the Controller Configuration

Weston Schreiber & Joshua Gabrielse “My robot doesn’t drive right!” (Did you use servos instead of motors?) check the labels servos have two wire cords and motors have three wire codes motors need to be plugged into speed controllers motors spin continuously (360° of rotation) the controller sets the speed (-127 to +127) servos spin back and forth (120° of rotation) the controller sets the location (-127 to +127) Servo (3-wire) Motor (2-wire)

Weston Schreiber & Joshua Gabrielse “My robot doesn’t drive right!” (Do you need to invert any of your motors?) Test drive your robot with all it’s wheels off the ground Look to see if any motors need to spin in the other direction Check Invert Direction to make a wheel spin in the other direction. Build & Download your modified code