Category Archives: Arduino 9-Axis IMU Totorials

In this lesson we need to become more comfortable working with objects in Vpython. WE will show how to create an animated thermometer using the simple commands we have already learned.

Arduino, Arduino 9-Axis IMU Totorials

9-Axis IMU LESSON 13: Introduction to Visual Python (Vpython)

November 7, 2019 admin

In this lesson we show you how to install Visual Python (Vpython) and show you how to begin to build 3D visuals. We introduce you to some of the basic objects and how how control how they look and where they are.

Arduino, Arduino 9-Axis IMU Totorials

9-Axis IMU LESSON 12: Passing Data From Arduino to Python

October 31, 2019 admin

In this lesson we show how to pass data from Arduino to Python using a Com Port. This is important for our 9-Axis IMU project as we want to take advantage of the processing power and 3D graphics capabilities of Python. Our goal is to get the date from Arduino to Python, and then create a dynamic 3D visualization of our system. The first step in this goal is to pass the data from arduino to Python.

In order to do this, a first step is to install the pyserial library. If you followed our python installation tutorial in lesson 11, then it is easy to install pyserial by just opening a windows command prompt, and then typing:

pip install pyserial

If this does not work, likely you did not install python according to the instruction in lesson 11.

In order to show a simple demonstration of passing data, we can use the following code on the arduino side, which just generates x, y, and z numbers and passes them to Python.

int x=0;
int y=0;
int z=0;
void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
x=x+1;
y=y+2;
z=z+4;

Serial.print(x);
Serial.print(",");
Serial.print(y);
Serial.print(",");
Serial.println(z);
delay(100);


}

int x=0;

int y=0;

int z=0;

void setup() {

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

Serial.begin(115200);

}

void loop() {

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

x=x+1;

y=y+2;

z=z+4;

Serial.print(x);

Serial.print(",");

Serial.print(y);

Serial.print(",");

Serial.println(z);

delay(100);

}

We can grab these numbers from the Com port on the Python side with the following code. Note that you should use the com port your arduino is on, which likely will not be the same as mine (which was ‘com5’).

import time
import serial
arduinoData=serial.Serial('com5',115200)
time.sleep(1)
while (True):
    while (arduinoData.inWaiting()==0):
        pass
    dataPacket = arduinoData.readline() #reply
    dataPacket=str(dataPacket,'utf-8')
    print(dataPacket)
    splitPacket=dataPacket.split(",")
    print (splitPacket)
    X=float(splitPacket[0])
    Y=float(splitPacket[1])
    Z=float(splitPacket[2])
    print ("X=",X," Y=",Y," Z=",Z)

import time

import serial

arduinoData=serial.Serial('com5',115200)

time.sleep(1)

while (True):

while (arduinoData.inWaiting()==0):

pass

dataPacket = arduinoData.readline() #reply

dataPacket=str(dataPacket,'utf-8')

print(dataPacket)

splitPacket=dataPacket.split(",")

print (splitPacket)

X=float(splitPacket[0])

Y=float(splitPacket[1])

Z=float(splitPacket[2])

print ("X=",X," Y=",Y," Z=",Z)

The above example is just a simple method for passing different channels from Arduino to Python.

For our IMU project, we want to use the code we left off with Lesson 10. However, note we can scale back on the number of data channels, because we just want the calibration data and then the final roll, pitch and yaw numbers. This is the arduino code that will pass those parameters.

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BNO055.h>
#include <utility/imumaths.h>
#include <math.h>
float thetaM;
float phiM;
float thetaFold=0;
float thetaFnew;
float phiFold=0;
float phiFnew;

float thetaG=0;
float phiG=0;

float theta;
float phi;

float thetaRad;
float phiRad;

float Xm;
float Ym;
float psi;

float dt;
unsigned long millisOld;

#define BNO055_SAMPLERATE_DELAY_MS (100)

Adafruit_BNO055 myIMU = Adafruit_BNO055();

void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
myIMU.begin();
delay(1000);
int8_t temp=myIMU.getTemp();
myIMU.setExtCrystalUse(true);
millisOld=millis();
}

void loop() {
  // put your main code here, to run repeatedly:
uint8_t system, gyro, accel, mg = 0;
myIMU.getCalibration(&system, &gyro, &accel, &mg);
imu::Vector<3> acc =myIMU.getVector(Adafruit_BNO055::VECTOR_ACCELEROMETER);
imu::Vector<3> gyr =myIMU.getVector(Adafruit_BNO055::VECTOR_GYROSCOPE);
imu::Vector<3> mag =myIMU.getVector(Adafruit_BNO055::VECTOR_MAGNETOMETER);
thetaM=-atan2(acc.x()/9.8,acc.z()/9.8)/2/3.141592654*360;
phiM=-atan2(acc.y()/9.8,acc.z()/9.8)/2/3.141592654*360;
phiFnew=.95*phiFold+.05*phiM;
thetaFnew=.95*thetaFold+.05*thetaM;

dt=(millis()-millisOld)/1000.;
millisOld=millis();
theta=(theta+gyr.y()*dt)*.95+thetaM*.05;
phi=(phi-gyr.x()*dt)*.95+ phiM*.05;
thetaG=thetaG+gyr.y()*dt;
phiG=phiG-gyr.x()*dt;

phiRad=phi/360*(2*3.14);
thetaRad=theta/360*(2*3.14);

Xm=mag.x()*cos(thetaRad)-mag.y()*sin(phiRad)*sin(thetaRad)+mag.z()*cos(phiRad)*sin(thetaRad);
Ym=mag.y()*cos(phiRad)+mag.z()*sin(phiRad);

psi=atan2(Ym,Xm)/(2*3.14)*360;

Serial.print(accel);
Serial.print(",");
Serial.print(gyro);
Serial.print(",");
Serial.print(mg);
Serial.print(",");
Serial.print(system);
Serial.print(",");
Serial.print(theta);
Serial.print(",");
Serial.print(phi);
Serial.print(",");
Serial.println(psi);

phiFold=phiFnew;
thetaFold=thetaFnew;

 
delay(BNO055_SAMPLERATE_DELAY_MS);
}

#include <Wire.h>

#include <Adafruit_Sensor.h>

#include <Adafruit_BNO055.h>

#include <utility/imumaths.h>

#include <math.h>

float thetaM;

float phiM;

float thetaFold=0;

float thetaFnew;

float phiFold=0;

float phiFnew;

float thetaG=0;

float phiG=0;

float theta;

float phi;

float thetaRad;

float phiRad;

float Xm;

float Ym;

float psi;

float dt;

unsigned long millisOld;

#define BNO055_SAMPLERATE_DELAY_MS (100)

Adafruit_BNO055 myIMU = Adafruit_BNO055();

void setup() {

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

Serial.begin(115200);

myIMU.begin();

delay(1000);

int8_t temp=myIMU.getTemp();

myIMU.setExtCrystalUse(true);

millisOld=millis();

}

void loop() {

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

uint8_t system, gyro, accel, mg = 0;

myIMU.getCalibration(&system, &gyro, &accel, &mg);

imu::Vector<3> acc =myIMU.getVector(Adafruit_BNO055::VECTOR_ACCELEROMETER);

imu::Vector<3> gyr =myIMU.getVector(Adafruit_BNO055::VECTOR_GYROSCOPE);

imu::Vector<3> mag =myIMU.getVector(Adafruit_BNO055::VECTOR_MAGNETOMETER);

thetaM=-atan2(acc.x()/9.8,acc.z()/9.8)/2/3.141592654*360;

phiM=-atan2(acc.y()/9.8,acc.z()/9.8)/2/3.141592654*360;

phiFnew=.95*phiFold+.05*phiM;

thetaFnew=.95*thetaFold+.05*thetaM;

dt=(millis()-millisOld)/1000.;

millisOld=millis();

theta=(theta+gyr.y()*dt)*.95+thetaM*.05;

phi=(phi-gyr.x()*dt)*.95+ phiM*.05;

thetaG=thetaG+gyr.y()*dt;

phiG=phiG-gyr.x()*dt;

phiRad=phi/360*(2*3.14);

thetaRad=theta/360*(2*3.14);

Xm=mag.x()*cos(thetaRad)-mag.y()*sin(phiRad)*sin(thetaRad)+mag.z()*cos(phiRad)*sin(thetaRad);

Ym=mag.y()*cos(phiRad)+mag.z()*sin(phiRad);

psi=atan2(Ym,Xm)/(2*3.14)*360;

Serial.print(accel);

Serial.print(",");

Serial.print(gyro);

Serial.print(",");

Serial.print(mg);

Serial.print(",");

Serial.print(system);

Serial.print(",");

Serial.print(theta);

Serial.print(",");

Serial.print(phi);

Serial.print(",");

Serial.println(psi);

phiFold=phiFnew;

thetaFold=thetaFnew;

delay(BNO055_SAMPLERATE_DELAY_MS);

}

Then, on the Python side we can grab and parse the data with this code.

import serial
import time
arduinoData=serial.Serial('com5',115200)
time.sleep(1)
while (1==1):
    while (arduinoData.inWaiting()==0):
        pass
    dataPacket=arduinoData.readline()
    
    dataPacket=str(dataPacket,'utf-8')
    splitPacket=dataPacket.split(',')
    Acal=float(splitPacket[0])
    Gcal=float(splitPacket[1])
    Mcal=float(splitPacket[2])
    Scal=float(splitPacket[3])
    Pitch=float(splitPacket[4])
    Roll=float(splitPacket[5])
    Yaw=float(splitPacket[6])
    print("Acal=",Acal,"Gcal=",Gcal,"Mcal=",Mcal,"Scal",Scal, "Pitch=",Pitch,"Roll=",Roll,"Yaw=",Yaw)

import serial

import time

arduinoData=serial.Serial('com5',115200)

time.sleep(1)

while (1==1):

while (arduinoData.inWaiting()==0):

pass

dataPacket=arduinoData.readline()

dataPacket=str(dataPacket,'utf-8')

splitPacket=dataPacket.split(',')

Acal=float(splitPacket[0])

Gcal=float(splitPacket[1])

Mcal=float(splitPacket[2])

Scal=float(splitPacket[3])

Pitch=float(splitPacket[4])

Roll=float(splitPacket[5])

Yaw=float(splitPacket[6])

print("Acal=",Acal,"Gcal=",Gcal,"Mcal=",Mcal,"Scal",Scal, "Pitch=",Pitch,"Roll=",Roll,"Yaw=",Yaw)

In the next lesson we will install Vpython and begin building our code to create dynamic 3D visualizations of our system.

Arduino, Arduino 9-Axis IMU Totorials

9-Axis IMU LESSON 11: Install Python

October 24, 2019 admin

This is a quick lesson where we show you how to install Python on a Windows 10 machine. We have gone about as far as we can go on our 9-axis IMU project using only the arduino. What we want to do now is to pass the data we are taking from arduino to Python, and then use python to do animations and 3D renderings. So, to move forward, we will need to install Python, which is explained in the video.

Arduino, Arduino 9-Axis IMU Totorials

9-Axis IMU LESSON 10: Making a Tilt Compensated Compass with Arduino

October 17, 2019 admin

In this lesson we show you how to build a demo tilt compensated compass using the BNO055 9-axis sensor. We go through some trigonometry to help you understand conceptually how the device works.

To play along at home, you will need an Arduino Nano, and an Adafruit BNO055 Inertial Measurement Sensor.

The code below is provided for your convenience. It is intended only for bench top demos, and should not be used in real applications. Just for fun, not for drones, or other actual control applications.

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BNO055.h>
#include <utility/imumaths.h>
#include <math.h>
float thetaM;
float phiM;
float thetaFold=0;
float thetaFnew;
float phiFold=0;
float phiFnew;

float thetaG=0;
float phiG=0;

float theta;
float phi;

float thetaRad;
float phiRad;

float Xm;
float Ym;
float psi;


float dt;
unsigned long millisOld;

#define BNO055_SAMPLERATE_DELAY_MS (100)

Adafruit_BNO055 myIMU = Adafruit_BNO055();

void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
myIMU.begin();
delay(1000);
int8_t temp=myIMU.getTemp();
myIMU.setExtCrystalUse(true);
millisOld=millis();
}

void loop() {
  // put your main code here, to run repeatedly:
uint8_t system, gyro, accel, mg = 0;
myIMU.getCalibration(&system, &gyro, &accel, &mg);
imu::Vector<3> acc =myIMU.getVector(Adafruit_BNO055::VECTOR_ACCELEROMETER);
imu::Vector<3> gyr =myIMU.getVector(Adafruit_BNO055::VECTOR_GYROSCOPE);
imu::Vector<3> mag =myIMU.getVector(Adafruit_BNO055::VECTOR_MAGNETOMETER);
thetaM=-atan2(acc.x()/9.8,acc.z()/9.8)/2/3.141592654*360;
phiM=-atan2(acc.y()/9.8,acc.z()/9.8)/2/3.141592654*360;
phiFnew=.95*phiFold+.05*phiM;
thetaFnew=.95*thetaFold+.05*thetaM;

dt=(millis()-millisOld)/1000.;
millisOld=millis();
theta=(theta+gyr.y()*dt)*.95+thetaM*.05;
phi=(phi-gyr.x()*dt)*.95+ phiM*.05;
thetaG=thetaG+gyr.y()*dt;
phiG=phiG-gyr.x()*dt;

phiRad=phi/360*(2*3.14);
thetaRad=theta/360*(2*3.14);

Xm=mag.x()*cos(thetaRad)-mag.y()*sin(phiRad)*sin(thetaRad)+mag.z()*cos(phiRad)*sin(thetaRad);
Ym=mag.y()*cos(phiRad)+mag.z()*sin(phiRad);

psi=atan2(Ym,Xm)/(2*3.14)*360;

Serial.print(acc.x()/9.8);
Serial.print(",");
Serial.print(acc.y()/9.8);
Serial.print(",");
Serial.print(acc.z()/9.8);
Serial.print(",");
Serial.print(accel);
Serial.print(",");
Serial.print(gyro);
Serial.print(",");
Serial.print(mg);
Serial.print(",");
Serial.print(system);
Serial.print(",");
Serial.print(thetaM);
Serial.print(",");
Serial.print(phiM);
Serial.print(",");
Serial.print(thetaFnew);
Serial.print(",");
Serial.print(phiFnew);
Serial.print(",");
Serial.print(thetaG);
Serial.print(",");
Serial.print(phiG);
Serial.print(",");
Serial.print(theta);
Serial.print(",");
Serial.print(phi);
Serial.print(",");
Serial.println(psi);

phiFold=phiFnew;
thetaFold=thetaFnew;

 
delay(BNO055_SAMPLERATE_DELAY_MS);
}

100

101

102

103

104

105

106

107

108

#include <Wire.h>

#include <Adafruit_Sensor.h>

#include <Adafruit_BNO055.h>

#include <utility/imumaths.h>

#include <math.h>

float thetaM;

float phiM;

float thetaFold=0;

float thetaFnew;

float phiFold=0;

float phiFnew;

float thetaG=0;

float phiG=0;

float theta;

float phi;

float thetaRad;

float phiRad;

float Xm;

float Ym;

float psi;

float dt;

unsigned long millisOld;

#define BNO055_SAMPLERATE_DELAY_MS (100)

Adafruit_BNO055 myIMU = Adafruit_BNO055();

void setup() {

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

Serial.begin(115200);

myIMU.begin();

delay(1000);

int8_t temp=myIMU.getTemp();

myIMU.setExtCrystalUse(true);

millisOld=millis();

}

void loop() {

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

uint8_t system, gyro, accel, mg = 0;

myIMU.getCalibration(&system, &gyro, &accel, &mg);

imu::Vector<3> acc =myIMU.getVector(Adafruit_BNO055::VECTOR_ACCELEROMETER);

imu::Vector<3> gyr =myIMU.getVector(Adafruit_BNO055::VECTOR_GYROSCOPE);

imu::Vector<3> mag =myIMU.getVector(Adafruit_BNO055::VECTOR_MAGNETOMETER);

thetaM=-atan2(acc.x()/9.8,acc.z()/9.8)/2/3.141592654*360;

phiM=-atan2(acc.y()/9.8,acc.z()/9.8)/2/3.141592654*360;

phiFnew=.95*phiFold+.05*phiM;

thetaFnew=.95*thetaFold+.05*thetaM;

dt=(millis()-millisOld)/1000.;

millisOld=millis();

theta=(theta+gyr.y()*dt)*.95+thetaM*.05;

phi=(phi-gyr.x()*dt)*.95+ phiM*.05;

thetaG=thetaG+gyr.y()*dt;

phiG=phiG-gyr.x()*dt;

phiRad=phi/360*(2*3.14);

thetaRad=theta/360*(2*3.14);

Xm=mag.x()*cos(thetaRad)-mag.y()*sin(phiRad)*sin(thetaRad)+mag.z()*cos(phiRad)*sin(thetaRad);

Technology Tutorials

Category Archives: Arduino 9-Axis IMU Totorials

9-Axis IMU LESSON 14: Introduction to Animating Objects in Vpython

9-Axis IMU LESSON 13: Introduction to Visual Python (Vpython)

9-Axis IMU LESSON 12: Passing Data From Arduino to Python

9-Axis IMU LESSON 11: Install Python

9-Axis IMU LESSON 10: Making a Tilt Compensated Compass with Arduino

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