Published December 16, 2021 © GPL3+

ME461 Wii Remote Controlled TMS320F28379D Launchpad Robot

This robot uses a custom breakout board, 3d printed parts, spi and serial communication to get data from a wii remote and pixy camera.

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ME461 Wii Remote Controlled TMS320F28379D Launchpad Robot

Things used in this project

Hardware components

Raspberry Pi 3 Model B

Texas Instruments LAUNCHXL-F28379D C2000 Delfino LaunchPad

Pixy2

DC Motor, 12 V

SparkFun USB UART Serial Breakout - CY7C65213

Inertial Measurement Unit (IMU) (6 deg of freedom)

Buzzer

Software apps and online services

Texas Instruments Code Composer Studio

Raspberry Pi Raspbian

Story

For our ME461 project we decided to make a semi autonomous robot. It takes input from a Wii remote via Bluetooth from a raspberry pi, tracks objects and acts accordingly from a Pixy camera, and uses an anti windup controller and a turning algorithm learned in class to control DC motors which is all implemented through a TMS320F28379D Launchpad that was sponsored from Texas Instruments.

After first learning how to program the Launchpad and its various features such as SPI communication, PWM, and the various timer interrupts, we were able to add our own components to the board from those that were already in our breakout board. We decided to add a raspberry pi that was communicated with through USB serial communication and a Pixy camera that was communicated through SPI. The Pixy camera has the ability to set multiple signatures (seven) that it can detect. A signature is a unique color and pattern that the Pixy can detect. In this project we have implemented functionality using three of the signatures and a function to get the location of each signature was added into the code.

On the raspberry pi, cwiid library was used in order to communicate with the Wii remote. A shell script was run connecting our raspberry pi to the specific address of the Wii remote. The buttons were mapped to specific buttons and events on the raspberry pi through an event library. Then, the button actions were processed and sent through serial as a binary string which was processed on the Launchpad.

overview

In the code on the launchpad, we programmed it so a stop sign signature on the Pixy would make the robot stop for 4 seconds. A blue flower signature was used as a symbol to follow which was done by centering it and going forward with the Pixy. An orange signature was used as a yield sign which set our plus minus variable which controls the speed to a small value in order to slow down the robot in all directions. The directional pad on the Wii remote moves the robot, the a button starts a song, the plus and minus also increments this plus and minus variable, the home button puts the plus and minus at the default. The one and two button turn this autonomous mode on and off. The b button is yet to be implemented, but the variable is ready to be used in the code.

Connecting the wii remote

To connect the wii remote, first build and run the file "connectwii.sh" in terminal as a superuser after updating your wii remote's bluetooth address. After running, press the 1 and 2 buttons synchronously to make the wii remote discoverable. The wii remote should connect and the player 1 button should light up. To check that it is working correctly, there is a program that can be run in terminal with "jstest-gtk".

showing the testing of the wiimote

To get the output, run "evtest.py" in python2. In the evtest code, make sure your serial output is the correct device and your wii remote is on the correct device. This code sends the binary output of the wii remote as a string which can be interpreted through the launchpad. A feature that was not implemented was sending it as the actual binary and implementing a reconnect feature in the code. I also wanted to make it all inclusive in the python using the os library to run the shell script, but running the script twice breaks the system. The two references that I used in order to do most of the connection to Bluetooth and getting the output can be found here.

https://www.instructables.com/Wiimote-Controller-Configuration-for-Raspberry-Pi-/

https://ericgoebelbecker.com/post/raspberry-pi-and-gamepad-programming-

part-1-reading-the-device/and-gamepad-programming-part-1-reading-the-device

Driving the robot in auto mode

remote driving the robot

Pixy documentation for setting up signatures:

https://docs.pixycam.com/wiki/doku.php?id=wiki:v2:teach_pixy_an_object_2

Pixy documentation for communication over SPI

https://docs.pixycam.com/wiki/doku.php?id=wiki:v2:porting_guide

#Justin Miner 12/8/21
#Before running this code, change the shell script to have the correct Bluetooth address

import os, serial
from evdev import InputDevice, categorize, ecodes
from time import sleep

#sees if the gamepad is already connected otherwise runs the script
#try:
#   gamepad = InputDevice('/dev/input/event0')
#except:
#    run the config script to connect the remote
#    os.system("sudo make ./connectwii.sh")
#    os.system("sudo ./connectwii.sh")
#    sleep(.5)
#    gamepad = InputDevice('/dev/input/event0')

#run the config script to connect the remote
#os.system("sudo make ./connectwii.sh")
#os.system("sudo .connectwii.sh")

#opens the serial connection
ser = serial.Serial("/dev/ttyUSB0", 115200)

#initialize variables for each button
a = 0
b = 0
minus = 0
plus = 0
home = 0
one = 0
two = 0
updown = 0
leftright = 0
txt = "{:011b}"

#array variables to store button values and past values
arr = []
arr1 = []

#message variable to give binary message
msg = 0;

#initialize the gamepad object
gamepad = InputDevice('/dev/input/event0')
#prints the specific gamepad
print(gamepad)

#each change in state is regarded as an event
for event in gamepad.read_loop():
        #finds the type of the event
        wiievent = categorize(event)
        
        #determines what to do for each type
        #first if is for direction pad events
        if event.type == ecodes.EV_ABS:  
            if ecodes.bytype[wiievent.event.type][wiievent.event.code] == 'ABS_X':
                leftright = wiievent.event.value
                if leftright == 1:
                    leftright = 2
                elif leftright == -1:
                    leftright = 1
            if ecodes.bytype[wiievent.event.type][wiievent.event.code] == 'ABS_Y': 
                updown = -1*wiievent.event.value
                if updown == 1:
                    updown = 2
                elif updown == -1:
                    updown = 1
        #this is for button presses (event codes correspond to each button)
        elif event.type == ecodes.EV_KEY:
            if event.code == 304:
                a = event.value
            if event.code == 305:
                b = event.value
            if event.code == 307:
                one = event.value
            if event.code == 308:
                two = event.value
            if event.code == 314:
                minus = event.value
            if event.code == 315:
                plus = event.value
            if event.code == 316:
                home = event.value
        
        #takes the old status and assigns it to previous array
        arr1 = arr
        arr = [a,b,one,two,minus,plus,home,updown,leftright]
        
        #checks for change in array to create new messsage
        if arr != arr1:
            message = 0
            for i in range(len(arr)):
                #checks if it is a 1 bit number or 2 bits (2 bits are stored at end)
                if i<8:
                    #adds to number in binary
                    message += arr[i] << i
                elif i==8:
                    message += arr[i] << i+1
            
            #formats number in text in order to output got rid of 0 message for less spam
            if message != 0:
                print(str.format(txt,message))
            ser.write("!" + str.format(txt,message) + "\n\r")
            sleep(0.1)

Credits

Justin Miner

1 project • 0 followers

Luke Zwilling

1 project • 0 followers

ME461 Wii Remote Controlled TMS320F28379D Launchpad Robot

Things used in this project

Hardware components

Software apps and online services

Story

Code

evtest

conectwii

mywinput

TMS Code

Credits

Justin Miner

Luke Zwilling

Comments

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ME461 Wii Remote Controlled TMS320F28379D Launchpad Robot

ME461 Wii Remote Controlled TMS320F28379D Launchpad Robot

Things used in this project

Hardware components

Software apps and online services

Story

Code

evtest

conectwii

mywinput

TMS Code

Credits

Justin Miner

Luke Zwilling

Comments

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