Apple Pi Robotics

Logic System

and

Programming Basics

Agenda

Review Control System Hardware

On Robot

Driver Station

Where to begin application code

LabView Interface

LabView Programming Fundamentals

Application Challenge

Control System

Hardware Controller

I/O and interface boards

Communications

Operator Interface

Software Operating System

Program Code

Let's Look at the Hardware

Rack/Processor/Communication

Analog Module

Digital I/O

Solenoid Module

Extra Slot

The cRIO I had 8 slots, the newer cRIO II has 4. Both are compatible, and both are legal in competitions, if you have an 8 slot you may only use the 1st 4 slots.

Additional HardwareAnalog Breakout

Up to 8 Analog sensors

12v Power from Power

Distribution Board

Analog Breakout Board

Jumper

Additional HardwareDigital Sidecar

All speed controllers (up to 10),

sensors (up to 16) and

relays (up to 8) connect to sidecar

Connect to 12V output on Power Distribution Board

Robot SignalLight

Additional HardwareSolenoid Breakout

Only used for pneumatics; spike relay,

pressure switch

12v Power from Power

Distribution Board

Solenoid Breakout Board

Driver Station

• Laptop

• Driver Station Software

• Joystick

• Custom Controls

• Dashboard

Laptop

• Classmate comes in the kit

• You can use any laptop that you like

• (Advanced) Software can run on the laptop and send data back to the robot, like vision processing

Driver Station Software

• Software that is run on the DS laptop

• Allows driver control of the robot

• Diagnostics of the communication to the robot

• Battery Voltage Read out

• Enter Key = Disable

• Spacebar Key = Emergency Stop (Use Enter normally)

If you press Spacebar you will have to restart the robot before you can disable it

Driver Station Software• 5 Tabs Provide Access to the different screens

• Operation

• Diagnostics

• Setup

• I/O

• Charts

If you press Spacebar you will have to restart the robot before you can disable it

Driver Station Operation Tab

Communication Status

Enable/Disable Buttons

Station Number for Competition

Use

User Messages (This area can be controlled by the robot program)

Team Number (Make sure it is

correct)

Communication Status

• Communication = a connection to the cRIO

• Robot Code = the user code is running

Battery Voltage Display

Mode Selection• Teleoperated = Driver• Autonomous = Computer

Control• Practice = Run like a

match

Elapsed time since start of robot

communication

PC Battery

Driver Station Diagnostics Tab

Joystick and IO LEDS: Green means they are active

Communication LEDS: Green means they are active

Hover over errors for messages that may help resolve issues

Firmware Versions: These must be stay up to date for you to work at competition

View Driver Station Log can be useful for debugging errors

Reboot cRIOUseful if you have an error that

a robot reset can fix

Driver Station Setup Tab

(Advanced) Allows you to configure

Remote Dashboard

Allows you to configure how the practice rounds are

setup

Team Number Configuration:

Make sure this is set correctly

Choose NIC: Allows you select

which network adapter is connected

to the robot

Joystick Setup:Drag Joystick up and

down to switch which connected joystick is 1, 2, 3 or 4 in the program

Exit: Logs off the Driver Station Account on the classmate

Driver Station I/O TabThis tab is used for configuring custom interfaces with the cypress I/O

module. If you aren’t using the cypress module you will not need this tab

There are several other ways to build custom I/O interfaces that don’t involve the cypress board or this I/O panel. You can find examples of these

on Chiefdelphi.com

Driver Station Charts Tab

• Lost Pkts = Lost Packets this is an indication of connection issues, if you have a large amount of lost packets there is something wrong with your connection between the robot and the DS

• Volts = A graph of battery voltage this can be very useful to find correlations between battery volatage and problems that occur with the robot

• Msecs = This is reporting your trip time, which is how long it takes for information to go from the driver station to the robot, this should also be small

• CPU% = this is the percentage of CPU your cRIO is using, minimizing this will allow for better performance

This tab helps you diagnose problems with your robot

Dashboard

The Dashboard can be used to get feedback from robot systems. This is the default Labview Dashboard

D-Link DAP 1522 Router/Bridge

• Connects Robot to Driver Station Laptop

• Allows wireless control of the robot

• Also called the Radio

• Should be mounted away from motors and speed controllers to avoid interference

D-Link DAP 1522 Router/Bridge

Power Light(blue)

Bridge Light(orange)

Access Point Light(blue)

Traffic Indicator Lights(blue)

D-Link DAP 1522 Router/Bridge rev.B

D-Link DAP 1522 Router/Bridge

Ethernet Ports AP/Bridge SwitchAP = Practice/Home

Bridge = At Competition

Reset Button

5v Power Connector Plugs in to grey power

inverter

Other Electrical SystemDevices

Sensors Limit Switches

Photo Detectors

Infrared Sensors

Encoders

Potentiometers

Gyro

Speed Controllers

Jaguars

Victors

Talons

Solenoids

Lights

Pressure Switches

Gyro

Relays

Let's Talk Application CodeWhere do we Start?

List Connected Hardware with purpose defined All Operator Interface

Pushbutton/Switches Meters Lights

All Robot Mounted Devices Limit switches Motor controllers Spike Relays Lights Photo sensors

Application CodeWhere do we Start?

Develop Sequence of Operations Documentation of how robot works; all

subsystems defined including the purpose

Ball collector/conveyor Shooter Drive train Knockdown

All ties back to the hardware list

Example:Knockdown Sequence of Operation

The purpose of the Knockdown arm is to allow for the lowering of the bridges that are used to cross from the offensive side of the field to the defensive side. It is also used for lowering of the bridge during the “end game” to allow the robot(s) to get on the bridge to attempt balancing.

Control devices include the “Arm Up” and “Arm Down” buttons on the Operator's joystick. The “Full Up” and “Full Down” limit switches control the stop points for actuation and prevent over travel. Both limit switches make use of the normally open contact. The “Knockdown Gearmotor” provides for the actuation of the arm. The motor operates clockwise for movement in the down direction (positive polarity) and counterclockwise for movement in the up direction (negative polarity).

Example:Knockdown Sequence of Operation

Operation: When the “Arm Down” button is depressed, the motor is commanded to rotate clockwise with a preset speed reference. The arm continues to advance in the down direction until either the button is released or the full down limit switch is engaged. If the button is released the arm stops at that point. If the full down limit switch is activated the arm stops in the down direction and can not be lowered further. Only the “Arm Up” button may be used at this location.

When the “Arm Up” button is depressed, the motor is commanded to rotate counter clockwise with a preset speed reference. The arm continues to advance in the up direction until either the button is released or the full up limit switch is engaged. If the button is released the arm stops at that point. If the full up limit switch is activated the arm stops in the up direction and can not be raised further. Only the “Arm Down” button may be used at this location.

LabView Interface Overview:1st do you have correct version installed?

• For those who don’t have correct version:

• We can start loading during initial discussion slides

• USB + 3 updates req’d

Open a blank “vi”

LabVIEW InterfaceEach Virtual Instrument (VI) has 2

WindowsFront Panel• User Interface (UI)

– Controls = Inputs– Indicators = Outputs

Block Diagram• Graphical Code

– Data travels on wires from controls through functions to indicators

– Blocks execute by Dataflow

Front Panel

Block Diagram

Block diagram execution Dependent on the flow of data

through wires Block diagram does NOT execute

left to right It is good practice to lay out

the code in an easy to follow left to right, top down manner

Function executes when data is available to ALL input terminals

Functions supply data to all output terminals when done

Dataflow Programming

30

Logic Thinking: What functions are needed, and in what order?

LabVIEW Interface

LabVIEW Interface

LabVIEW Interface – function setsLabVIEW palette sets

Programming

FRC specific palettes FIRST Vision

WPI Robotics Library

PID Toolkit palette

Context Help

WPI Robotics Library Interfaces with cRIO, sensors & actuators

Contains multiple palettesRobot Drive

Sensors

Actuators

IO

Driver Station

Camera

Communications

Utilities

LabVIEW InterfaceSample Block Diagram

LabVIEW Interface

LabVIEW InterfaceHelp»Show Context Help, press the <Ctrl+H>

keysHover cursor over object to update window

Additional Help

– Right-Click on the VI icon and choose Help, or

– Choose “Detailed Help.” on the context help window

LabVIEW Best PracticesCreate a New Folder in your work directory for your

LabVIEW work call it “Labview Data”You will save all your VIs & Projects to this folder.

Saving your VI frequently is good, but know that once you choose to save your VI, it resets the ‘undo call’ (Ctrl-Z) and you will not be able to go back on any steps you made before saving your VI.

Think function-to-function programming and not line-by-lineAvoid crossing wires while connecting different objects on

the block diagram. Crossed wires can be confusing to read and follow at times. (but can be unavoidable )

When in doubt, DEBUG! Use the light bulb icon on the status toolbar on the block diagram to highlight the path of the flow of data.

LabVIEW Best Practices

Place output indicators at multiple steps during the data flow path of your VI to keep track of the output as it changes through the VI.

PLAN PLAN and PLAN! Plan out the various stages of your VI/Program prior to placing objects on the block diagram. This will make it easier to end up with a clean picture of code and will also allow you to pick out the functions that best suit your needs.

PRACTICE! The only way to get better at LabVIEW is

to practice.

We will teach basics and principles in next few weeks

In order to be proficient – independent work is required

LabView for FRCA template is provided to set up the code

Open Labview FRC 20131. Select New FRC cRio Robot Project 2. Change Project name 3. Set IP Address to 10.20.67.02, select “Finish”4. In “Project Explorer” window select “Robot Main”

• Project explorer links multiple vi’s (Virtual Instruments)

That's All Folks!