teacher/mentor institute using easyc joel kirkland july 30-31, 2015

Teacher/Mentor Institute

Using easyC

Joel KirklandJuly 30-31, 2015

Outline

Intro to Programming (or Coding) Intro to easyC easyC user interface (IDE) Basic example program Debugging Tips Additional TMI easyC Training

Breakout sessions on Friday – Intro and Advance

Charts for Hands-On Session: Building a Robot Intro

Additional charts in TMI Notebook 1 hour easyC Breakout session at Kickoff for

Teachers, Mentors and Students

Programming Overview

Connects inputs to robot outputs Read Joystick or sensors (inputs) Determines when and how motors

and servos operate (outputs) Program structure uses decision and

logic statements to determine robot responses

Used to fit the requirements of the game and your robot design

Traditional Syntax

Traditional C syntax can be imposing

Program structure is not obvious without experience

Program Flow

Flow charts can help show structure of a process or a program

More intuitive

easyC Example

• Combines both graphical and textual representations of code

• easyC is a simpler version of the C programming language for the VEX Cortex with graphical, drag and drop interface

easyC User Interface (IDE)

Menus

Function

Blocks

Icons

Project Explorer

easyC User Interface - Menus

Menu Usage: File Menu: New Project, Open, Close, Print Edit Menu: Undo, Edit, Copy, Paste, Find Project Menu: Project Type, Add Function, Import Function, Library Import

Build and Download Menu: Compile, Build and Download, Reload Default IFI Code Tools: Terminal Window, Download Window, On-Line Window Window: Block Layout, Block & C Layout Help Menu: Contents, Registration, Updates

easyC User Interface - Icons

Icons

New Project

New Competition

Project

Open

Save

Start Page Enable

Function Blocks Enable

Project Explorer Enable

Output Panel Enable

Controller Configuration

Global Variables

Compile

Compile and

Download

Terminal Window

Graphic Display

On-line Window

Find

Zoom

easyC User Interface – Function Blocks

Program Flow Wait, If, Else, While, Timer, Assignment Inputs Limit Switch, Digital Input, Analog Input, Potentiometer Outputs Motor / Servo Module, Digital Output

Joystick Tank (2 Stick) , Arcade (Single Stick), Motor to Joystick, Motor to Digital (Button), Get Digital, Get Joystick Mathematics SIN, COS, TAN, Power, Random

easyC User Interface - Project Explorer

Advance Capabilities:Controller Configuration Change Inputs and Output, Label Ports Macros and Constants Create Definitions (aka C #define) Global Variables Variable with Global Program Scope

Block Diagram Select Between Functions Source & Header Files Create or Import .c and .h files, Write C-Code Freehand Library Files Import a easyC® library

Creating a New Program

Select: File…New Competition Project

Select: Field Control Competition Project

We are going to need a statement that is always true in order for the program to execute more than once

We need to add a While Loop To do this, go to the Function Blocks box beside your

program and click the “+” beside Program Flow

Start Programming

Simple Program Example

• This simple program can be modified to add additional motors and/or servos

• The remaining charts describe the creation of this program

Then click and drag While Loop from the list and place it on the vertical line between Variables box and End box.

At this point a dialog box appears Type a true expression

such as (2<3) or 1 Click OK

While Loop

While Loop Example

• This is an example of an inserted While Loop

• Without the While Loop, all the statements in the program will only execute once. Your robot will not move when the Cortex is turned on

Inside the While Loop a set of brackets appear, this is where you add additional statements

First add a motor to the program Click the “+” beside Joystick under the

Function Blocks Click and drag the Joystick To Motor function

to the vertical line between the brackets in your While Loop

When you do this, a dialog box appears which is displayed on the next page

Motor Programming (1 of 2)

The Joystick to Motor dialog box for Motor Selection: We can not use Motor

1 in the competition For this example we

will use Motor 2 Click on the down

arrow in the motor box and select Motor 2

Motor Numbers 1 and 10 are not permitted for use in competition and are not used in the program

Motor Programming (2 of 2)

Transmitter is always set to Joystick # 1 Transmitter Channel allows you to select which

buttons or joysticks on the Joystick Controller you want to use for a specific purpose In this program we are going to use the left hand joystick

to operate the wheels and the right hand joystick to operate an arm and a claw

We can also change the Channel the same way as we changed the Motor For this example we will use Channel 1 Which just so happens to be the default Finally click Ok

You can create as many motor functions as you need for your program.

Joystick Transmitter Channel

You will use the Channel 1 on the Joystick Controller to operate the motor

Move the Right Joystick left or right to control the Motor

Using the Joystick Controller – Channel 1

One of the most commonly used wheel configurations is a wheel on each side of the robot

To avoid spinning in circles, the motors need to spin in opposite directions

The wheels need to spin at the same rate (move the robot straight forward and backward) and spin at different rates (turn the robot)

This can be achieved in an Arcade Function

Creating a Program for Wheels

Arcade Drive Example(page 1 of 2)

This function drives a robot with motors connected to motor numbers 2 (left) and 3 (right), using joystick channels 2 (left stick vertical) and 1 (right stick horizontal)

Arcade Drive Example

(page 2 of 2)

Motor Numbers

Joystick Channels

Motor Direction

To operate the wheels properly the direction of one of the motors needs to reversed (aka inverted) Invert Direction for Left Motor 6 by clicking the

down arrow of Invert Direction and selecting 1 If the robot goes backwards, change Invert

Direction of Left Motor 6 to 0 and select 1 under Invert Direction for Right Motor 8

Finally click OK The motor direction may also be changed by

reversing the leads on the motor

Arcade Programming - Invert Direction of Motors

To operate a servo with the Joystick Controller Go back to Joystick in the Function Block Click and drag the Joystick to Servo function to

your While Loop and place it on the vertical line between the JoystickToMotor function box and the lower bracket box

When you do this, another dialog box will appearo Except for the Servo title, it looks identical to the

Motor Dialog Box For the example program

Set the Channel to 2 and the Motor to 4 the same way as the Motor was configured

Click OK

Servo Programming

Simple Program Example

• This simple program demonstrates most of the functionality used to control your Mini-Robot

• Additional training later in the workshop

• Kickoff event includes an hour training session for your students.

easyC On-Line Window

The easyC On-Line Window allows the user to see and control motors and sensors attached to the robot in real time. This can be enabled at any time.

Note: The On-Line Window requires a program, even blank, be downloaded after updating the master firmware.

Debugging Tip: Can be used to identify & correct errors with input and output assignment or wiring

easyC Terminal Window

The easyC allows users to see output from PrintToScreen calls form within their program while the program is running on the Cortex

Debugging Tip: Printing to screen helps to provide feedback internal state

easyC Terminal Window

The easyC allows users to see output from GraphicDisplay calls form within their program while the program is running on the Microcontroller. The Graphic Display is a more advanced type of feedback that allows values to placed on grid instead of scrolling.

See Samples –> “Graphic Display Joystick Test” for code.

Debugging Tip: Similar to printing but provides a continuous display of internal program variables/inputs/outputs

teacher/mentor institute using easyc joel kirkland july 30-31, 2015

Documents

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