9-Axis IMU LESSON 18: Visualizing Pitch and Yaw in Vpython

December 5, 2019 admin

In this lesson we show you how to visualize Yaw and Pitch in Vpython. We create a visual representation of our breadboard, Arduino Nano, and BNO055 and then rotate it in three dimensions with and without pitch. For your convenience, the code we developed in this video are presented below.

# ====================================================================
# DISCLAIMER:
# This code is provided as-is for educational and experimental 
# purposes only. The author makes no representations or warranties of 
# any kind concerning the safety, suitability, or accuracy of this 
# code. Use at your own risk. The author assumes no liability for any 
# damages, system failures, security breaches, or network issues 
# resulting from the use or implementation of this script.
# ====================================================================

from vpython import *
from time import *
import numpy as np
import math

scene.range=5
toRad=2*np.pi/360
toDeg=1/toRad
scene.forward=vector(-1,-1,-1)

scene.width=600
scene.height=600

xarrow=arrow(lenght=2, shaftwidth=.1, color=color.red,axis=vector(1,0,0))
yarrow=arrow(lenght=2, shaftwidth=.1, color=color.green,axis=vector(0,1,0))
zarrow=arrow(lenght=4, shaftwidth=.1, color=color.blue,axis=vector(0,0,1))

frontArrow=arrow(length=4,shaftwidth=.1,color=color.purple,axis=vector(1,0,0))
upArrow=arrow(length=1,shaftwidth=.1,color=color.magenta,axis=vector(0,1,0))
sideArrow=arrow(length=2,shaftwidth=.1,color=color.orange,axis=vector(0,0,1))

bBoard=box(length=6,width=2,height=.2,opacity=.8,pos=vector(0,0,0,))
bn=box(length=1,width=.75,height=.1, pos=vector(-.5,.1+.05,0),color=color.blue)
nano=box(lenght=1.75,width=.6,height=.1,pos=vector(-2,.1+.05,0),color=color.green)
myObj=compound([bBoard,bn,nano])
while (True):
    pitch=45*toRad
    for yaw in np.arange(0,2*np.pi,.01):
        rate(50)
        k=vector(cos(yaw)*cos(pitch), sin(pitch),sin(yaw)*cos(pitch))
        y=vector(0,1,0)
        s=cross(k,y)
        v=cross(s,k)

        frontArrow.axis=k
        sideArrow.axis=s
        upArrow.axis=v
        myObj.axis=k
        myObj.up=v
        sideArrow.length=2
        frontArrow.length=4
        upArrow.length=1

# ====================================================================

# DISCLAIMER:

# This code is provided as-is for educational and experimental

# purposes only. The author makes no representations or warranties of

# any kind concerning the safety, suitability, or accuracy of this

# code. Use at your own risk. The author assumes no liability for any

# damages, system failures, security breaches, or network issues

# resulting from the use or implementation of this script.

# ====================================================================

from vpython import *

from time import *

import numpy as np

import math

scene.range=5

toRad=2*np.pi/360

toDeg=1/toRad

scene.forward=vector(-1,-1,-1)

scene.width=600

scene.height=600

xarrow=arrow(lenght=2, shaftwidth=.1, color=color.red,axis=vector(1,0,0))

yarrow=arrow(lenght=2, shaftwidth=.1, color=color.green,axis=vector(0,1,0))

zarrow=arrow(lenght=4, shaftwidth=.1, color=color.blue,axis=vector(0,0,1))

frontArrow=arrow(length=4,shaftwidth=.1,color=color.purple,axis=vector(1,0,0))

upArrow=arrow(length=1,shaftwidth=.1,color=color.magenta,axis=vector(0,1,0))

sideArrow=arrow(length=2,shaftwidth=.1,color=color.orange,axis=vector(0,0,1))

bBoard=box(length=6,width=2,height=.2,opacity=.8,pos=vector(0,0,0,))

bn=box(length=1,width=.75,height=.1, pos=vector(-.5,.1+.05,0),color=color.blue)

nano=box(lenght=1.75,width=.6,height=.1,pos=vector(-2,.1+.05,0),color=color.green)

myObj=compound([bBoard,bn,nano])

while (True):

pitch=45*toRad

for yaw in np.arange(0,2*np.pi,.01):

rate(50)

k=vector(cos(yaw)*cos(pitch), sin(pitch),sin(yaw)*cos(pitch))

y=vector(0,1,0)

s=cross(k,y)

v=cross(s,k)

frontArrow.axis=k

sideArrow.axis=s

upArrow.axis=v

myObj.axis=k

myObj.up=v

sideArrow.length=2

frontArrow.length=4

upArrow.length=1

Arduino, Arduino 9-Axis IMU Totorials

9-Axis IMU LESSON 17: Review of Basic Trigonometry

December 5, 2019 admin

In this video we review the basic trigonometry needed in order to get the Vpython visualization to work. With this quick trig tutorial, you should have the math you need to finish the project.

Arduino, Tutorial

Arduino Tutorial 39: Using a Joystick to Control DC Motor Speed and Direction

December 3, 2019 admin

DC Motor JoyStick — This is a simple example of how to control speed and direction of a DC motor with a joystick.

Lesson 37 and 38 showed some preliminary concepts in controlling a DC motor using an arduino and the L293D motor controller. In the video above we show how to control the speed and direction of a simple DC motor using a joystick. In the neutral position, the motor is stationary. Then the speed smoothly increases as you move the joystick forward, until you reach maximum speed. Similarly, in pulling the joystick back from the neutral position, the motor gradually increases speed in the reverse direction. The diagram below shows the basic motor control schematic we are working from.

Connection Diagram for a DC Motor Controller using the L293 Control Chip

In the circuit diagram above, we also add a wire to connect the arduino ground to the power supply ground. It is always good to have all components connected to a common ground rail. Of course, you also need to add the joystick controller as shown in the video.

This is the code we used in this

int speedPin=5;
int dir1=4;
int dir2=3;
int mSpeed;
int jPin=A1;
int jVal;

void setup() {
  // put your setup code here, to run once:
pinMode(speedPin,OUTPUT);
pinMode(dir1,OUTPUT);
pinMode(dir2,OUTPUT);
pinMode(jPin,INPUT);
Serial.begin(9600);

}

void loop() {
  // put your main code here, to run repeatedly:
jVal=analogRead(jPin);

Serial.println(jVal);
if (jVal<512){
digitalWrite(dir1,LOW);
digitalWrite(dir2,HIGH);
mSpeed=-255./512.*jVal+255.;
analogWrite(speedPin,mSpeed);
}
if(jVal>=512){
digitalWrite(dir1,HIGH);
digitalWrite(dir2,LOW);
mSpeed=(255./512.)*jVal-255.;
analogWrite(speedPin,mSpeed);
}
}

int speedPin=5;

int dir1=4;

int dir2=3;

int mSpeed;

int jPin=A1;

int jVal;

void setup() {

// put your setup code here, to run once:

pinMode(speedPin,OUTPUT);

pinMode(dir1,OUTPUT);

pinMode(dir2,OUTPUT);

pinMode(jPin,INPUT);

Serial.begin(9600);

}

void loop() {

// put your main code here, to run repeatedly:

jVal=analogRead(jPin);

Serial.println(jVal);

if (jVal<512){

digitalWrite(dir1,LOW);

digitalWrite(dir2,HIGH);

mSpeed=-255./512.*jVal+255.;

analogWrite(speedPin,mSpeed);

}

if(jVal>=512){

digitalWrite(dir1,HIGH);

digitalWrite(dir2,LOW);

mSpeed=(255./512.)*jVal-255.;

analogWrite(speedPin,mSpeed);

}

An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

Arduino, Arduino 9-Axis IMU Totorials

9-Axis IMU LESSON 16: How to Install and Configure Pyscripter

November 28, 2019 admin

As we move forward, we could really benefit from a better text editor than IDLE to edit our Python Code. In today’s lesson I show you how to download and install Pyscripter, which will make your python coding much easier. I suggest you follow these instructions and move to Pyscripter, as I will be using it for future lessons.

Arduino, Tutorial

Arduino Tutorial 38: Using a Tilt Switch Cut Off With a DC Motor

November 26, 2019 admin

Tilt Cut Off Switch — DC Motor circuit with a tilt switch cutoff

In this lesson we explore how to add a tilt cutoff to our DC motor project. In many cases, you may want to automatically turn your motors off in the case where your project or robot tips over. The tilt switch is a simple way to do this. The video below takes you through the process step-by-step.

If you need help hooking the circuit up, the diagram below shows you a schematic of what we are working with. An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

In addition, you will need to add the tilt switch, as shown in the video.

Below is the code we used, with the tilt switch connected to pin 2 on the arduino.

int speedPin=5;
int dir1=4;
int dir2=3;
int mSpeed=255;
int tiltPin=2;
int tiltVal;

void setup() {
  // put your setup code here, to run once:
pinMode(speedPin,OUTPUT);
pinMode(dir1,OUTPUT);
pinMode(dir2,OUTPUT);
pinMode(tiltPin,INPUT);
digitalWrite(tiltPin,HIGH);
Serial.begin(9600);

}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(dir1,LOW);
digitalWrite(dir2,HIGH);
tiltVal=digitalRead(tiltPin);
Serial.println(tiltVal);
if (tiltVal==0){
  analogWrite(speedPin,mSpeed);
}
if (tiltVal==1){
  analogWrite(speedPin,0);
}

}

int speedPin=5;

int dir1=4;

int dir2=3;

int mSpeed=255;

int tiltPin=2;

int tiltVal;

void setup() {

// put your setup code here, to run once:

pinMode(speedPin,OUTPUT);

pinMode(dir1,OUTPUT);

pinMode(dir2,OUTPUT);

pinMode(tiltPin,INPUT);

digitalWrite(tiltPin,HIGH);

Serial.begin(9600);

}

void loop() {

// put your main code here, to run repeatedly:

digitalWrite(dir1,LOW);

digitalWrite(dir2,HIGH);

tiltVal=digitalRead(tiltPin);

Serial.println(tiltVal);

if (tiltVal==0){

analogWrite(speedPin,mSpeed);

}

if (tiltVal==1){

analogWrite(speedPin,0);

}

Technology Tutorials

9-Axis IMU LESSON 18: Visualizing Pitch and Yaw in Vpython

9-Axis IMU LESSON 17: Review of Basic Trigonometry

Arduino Tutorial 39: Using a Joystick to Control DC Motor Speed and Direction

9-Axis IMU LESSON 16: How to Install and Configure Pyscripter

Arduino Tutorial 38: Using a Tilt Switch Cut Off With a DC Motor

Making The World a Better Place One High Tech Project at a Time. Enjoy!