1. Apple Pi Robotics
Logic System
and
Programming Basics 1 1

2. Agenda Review Control System Hardware LabView Programming Fundamentals
On Robot
Driver Station
Where to begin application code
LabView Interface
LabView Programming Fundamentals
Application Challenge
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 2 2

3. Control System Hardware Software Controller I/O and interface boards
Communications
Operator Interface
Software
Operating System
Program Code
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 3 3

4. Let's Look at the Hardware
Rack/Processor/Communication
Analog Module
Digital I/O
Solenoid Module
Extra Slot
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982
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. 4 4

5. 12v Power from Power Distribution Board
Additional Hardware Analog Breakout
12v Power from Power Distribution Board
Up to 8 Analog sensors
Jumper
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982
Analog Breakout
Board 5 5

6. All speed controllers (up to 10), relays (up to 8) connect to sidecar
Additional Hardware Digital Sidecar
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982
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 Signal
Light 6 6

7. Digital Sidecar Connections7
Digital Sidecar Connections
Status LEDs: These should always be green when robot is turned on
PWM Outputs: Connect up to 10 Speed Controllers
Servos also connect here must have a jumper on power pins to function
Power connection: Connect to 12V output on Power Distribution Board
Connects to the cRIO Digital Module
Robot Signal Light Connector
Sidecar image:
Relay Indicator Lights
Red = REV
Green = FWD
Relay Outputs: Connect up to 8 Spike Relays
Digital I/O: connect up to 14 digital sensors 7 7

8. Additional Hardware Solenoid Breakout
12v Power from Power Distribution Board
Only used for pneumatics; spike relay, pressure switch
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982
Solenoid Breakout
Board 8 8

9. Driver Station Laptop Driver Station Software Joystick Custom Controls
Dashboard 9

10. 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 10

11. 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 11

12. 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 12

13. Driver Station Operation Tab
Battery Voltage Display
Team Number (Make sure it is correct)
Mode Selection
Teleoperated = Driver
Autonomous = Computer Control
Practice = Run like a match
Elapsed time since start of robot communication
PC Battery
Communication Status
Communication = a connection to the cRIO
Robot Code = the user code is running
User Messages (This area can be controlled by the robot program)
Communication Status
Enable/Disable Buttons
Station Number for Competition Use 13

14. Driver Station Diagnostics Tab
Communication LEDS:
Green means they are active
Hover over errors for messages that may help resolve issues
View Driver Station Log
can be useful for debugging errors
Joystick and IO LEDS:
Green means they are active
Firmware Versions:
These must be stay up to date for you to work at competition
Reboot cRIO
Useful if you have an error that a robot reset can fix 14

15. Driver Station Setup Tab
Team Number Configuration: Make sure this is set correctly
Choose NIC: Allows you select which network adapter is connected to the robot
(Advanced) Allows you to configure Remote Dashboard
Allows you to configure how the practice rounds are setup
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 15

16. 1616
Driver Station I/O Tab
This 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
Cypress I/O Module Information can be found here:
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 16

17. Driver Station Charts Tab
This tab helps you diagnose problems with your robot
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 17

18. Dashboard
The Dashboard can be used to get feedback from robot systems. This is the default Labview Dashboard 18

19. D-Link DAP 1522 Router/Bridge
1919
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
Image 1:
Image 2: 19

20. D-Link DAP 1522 Router/Bridge Traffic Indicator Lights
2020
D-Link DAP 1522 Router/Bridge
Image:
Power Light
(blue)
Bridge Light
(orange)
Access Point Light
(blue)
Traffic Indicator Lights
(blue) 20

21. D-Link DAP 1522 Router/Bridge rev.B
2121
D-Link DAP 1522 Router/Bridge rev.B
Image: 21

22. D-Link DAP 1522 Router/Bridge
2222
D-Link DAP 1522 Router/Bridge
Image:
5v Power Connector Plugs in to grey power inverter
Ethernet Ports
AP/Bridge Switch
AP = Practice/Home
Bridge = At Competition
Reset Button 22

23. Other Electrical System
Devices
Sensors
Limit Switches
Photo Detectors
Infrared Sensors
Encoders
Potentiometers
Gyro
Speed Controllers
Jaguars
Victors
Talons
Solenoids
Lights
Pressure Switches
Gyro
Relays
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 23 23

24. Let's Talk Application Code Where 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
Photo sensors
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 24 24

25. Application Code Where 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
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 25 25

26. Knockdown Sequence of Operation
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).
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 26 26

27. Knockdown Sequence of Operation
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.
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 27 27

28. 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” 28

29. LabVIEW Interface Each Virtual Instrument (VI) has 2 Windows
Front 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 29 29

30. Dataflow Programming 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
Note – this slide is hidden
LabVIEW follows a dataflow model for running VIs. A block diagram node executes when all its inputs are available. When a node completes execution, it supplies data to its output terminals and passes the output data to the next node in the dataflow path. Visual Basic, C++, JAVA, and most other text-based programming languages follow a control flow model of program execution. In control flow, the sequential order of program elements determines the execution order of a program.
Consider the block diagram above. It adds two numbers and then multiplies by 2 from the result of the addition. In this case, the block diagram executes from left to right, not because the objects are placed in that order, but because one of the inputs of the Multiply function is not valid until the Add function has finished executing and passed the data to the Multiply function. Remember that a node executes only when data are available at all of its input terminals, and it supplies data to its output terminals only when it finishes execution. In the second piece of code, the Simulate Signal Express VI receives input from the controls and passes its result to the Graph.
You may consider the add-multiply and the simulate signal code to co-exist on the same block diagram in parallel. This means that they will both begin executing at the same time and run independent of one another. If the computer running this code had multiple processors, these two pieces of code could run independent of one another (each on its own processor) without any additional coding.
Logic Thinking: What functions are needed, and in what order? 30 30
© National Instruments Corporation 14 Introduction to LabVIEW Hands-On

31. LabVIEW Interface 31 31

32. LabVIEW Interface 32 32

33. LabVIEW Interface – function sets
3333
LabVIEW Interface – function sets
LabVIEW palette sets
Programming
FRC specific palettes
FIRST Vision
WPI Robotics Library
PID Toolkit palette
Context Help
LabVIEW palette – initial view is restricted for new users. In order to switch to the full palette set – use Switch Palette Set… in the tools menu. You get the standard LabVIEW palettes as well as 2 palettes that are specific to the FRC competition. FIRST Vision and WPI Robotics Library. The FIRST Vision palette will be mainly discussed in a later session. This session will focus primarily on the WPI Robotics Library. In addition to standard LabVIEW, we have also included the PID toolkit in the FRC installation. We will cover PID basics in the sessions as well.
All of the functions in the palettes have additional help associated with them. If you have Context Help open (Ctrl-H) you can get a brief description of a palette or function with the option to access more detailed help. 33

34. WPI Robotics Library Interfaces with cRIO, sensors & actuators
3434
WPI Robotics Library
Interfaces with cRIO, sensors & actuators
Contains multiple palettes
Robot Drive
Sensors
Actuators IO
Driver Station
Camera
Communications
Utilities
WPI is used to interface with various devices including the cRIO, sensors, actuators, the camera, the driver station etc…
The functionality will match what is available in the C/C++ version of WPI Lib, but because of language differences, the actual implementation may differ.
Talk about the different palettes in a greater detail: 34

35. LabVIEW Interface
Sample Block Diagram 35 35

36. LabVIEW Interface 36 36

37. LabVIEW Interface 37 37

38. LabVIEW Interface
Help»Show Context Help, press the <Ctrl+H> keys
Hover 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 38 38

39. LabVIEW Best Practices
Create 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-line
Avoid 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.
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 39 39

40. 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
From: Lee Harrisberger, "Engineersmanship ... The Doing of Engineering Design," 2nd Ed,
Brooks/Cole Engineering Division, Monterey CA, 1982 40 40

41. LabView for FRC A template is provided to set up the code
Open Labview FRC 2013
Select New FRC cRio Robot Project
Change Project name
Set IP Address to , select “Finish”
In “Project Explorer” window select “Robot Main”
Project explorer links multiple vi’s (Virtual Instruments)

42. That's All Folks! 42 42