2 wheel balancing robot

Hi Anvesh,

I imagine you are referring to the following Instructable: www.instructables.com/.../

As shown in step 5, the code was uploaded to Google Drive: drive.google.com/folderview

It seems that most self-balancing robots use an Arduino board of some form: www.intorobotics.com/.../

If you would like to use a MSP432 then you will need to port the existing Arduino code to Energia: http://energia.nu/guide/

I imagine that a robust balancing robot solution will have no other choice but to incorporate PID control loop feedback with the gyroscope inputs available. Assuming that you would like to use Energia, libraries are added by placing them inside the hardware\msp430\libraries folder of the Energia install folder (energia-xxxxxxxxx) followed by selecting sketch -> Import Library inside of Energia.

energia.nu/Tutorial_Library.html
energia.nu/Libraries.html

Regards,
Ryan

Hi Anvesh,

Take a look at this hackster.io project as well: www.hackster.io/.../wifi-enabled-balancing-bot-33dab1

Cheers!

Hi thanks for your reply im just going with these code below, m struggling hard to implement PID controller code to my code
you can have a look at my code
//#include <Adafruit_TMP006.h>
#include<Energia.h>
// A0: self test, A1: z-axis, A2: y-axis, A3: x-axis, A4: ground, A5: vcc
//const int groundpin = 18; // digital input pin 4 -- ground
//const int powerpin = 19; // digital input pin 5 -- voltage
const int xpin = 24; // x-axis of the accelerometer
const int ypin = 25; // y-axis
const int zpin = 26; // z-axis (only on 3-axis models)
const float pi = 3.14;
const int enableA=31;
const int enableB=32;
const int direction1=33;
const int direction2=34;
//float degreeint=86.6;
float error=0;
float errorB=0;
//float degreeA=90.1;
//float refdegree=91;
float refdegree=90;
float present;
float presentB;

//int ActPos = degree_x; // select the input pin for feedback signal
int DesPos = 90; // select the input pin for control signal

byte PWMOutput;
//long Error[10];
long Accumulator;
long PID;
int PTerm=10;
int ITerm=50;
int DTerm=30;
byte Divider=10;




//const int Voffset = 1.65;
const float Sensitivity = 0.3;

void setup()
{
Serial.begin(9600);
//Serial.print(127);

//pinMode(groundpin, OUTPUT); // Provide ground and power by using the digital inputs as normal
//pinMode(powerpin, OUTPUT); // digital pins. This makes it possible to directly connect the
// digitalWrite(groundpin, 0); // breakout board to the Arduino. If you use the normal 5V and
// digitalWrite(powerpin, HIGH);
pinMode(31,OUTPUT);
pinMode(32,OUTPUT);
pinMode(33,OUTPUT);
pinMode(34,OUTPUT);
// GND pins on the Arduino, you can remove these lines +
analogWrite(enableA,0);
analogWrite(enableB,0);
}

void loop()
{
float Vout_x = analogRead(xpin); // x axis /*do we need the step value here?*/
float Vout_y = analogRead(ypin); // y axis
float Vout_z = analogRead(zpin); // z axis

float Vm_x = Vout_x * .003223; // Vmeasured for x axis
float Vm_y = Vout_y * .003223; // Vmeasured for y axis
float Vm_z = Vout_z * .003223; // Vmeasured for z axis

float x= Vm_x - 1.64;
float y= Vm_y - 1.62;
float z= Vm_z - 1.98;

Serial.print("X-axis ");
Serial.print(digitalRead(xpin), DEC); // print the sensor values
Serial.print("\t");
Serial.print("Y-axis ");
Serial.print(digitalRead(ypin), DEC);
Serial.print("\t");
Serial.print("Z-axis ");
Serial.println(digitalRead(zpin), DEC);



//delay(500); // delay before next reading


float R_x = (x/(Sensitivity)); //radians
float R_y = (y/(Sensitivity));
float R_z = (z/(Sensitivity));

Serial.print("x = ");
Serial.println(x, DEC);
Serial.print("y = ");
Serial.println(y, DEC);
Serial.print("z = ");
Serial.println(z, DEC);



float Angle_x = acos(R_x);
float Angle_y = acos(R_y);
float Angle_z = acos(R_z);

float degree_x = (180/pi)*Angle_x;
float degree_y = (180/pi)*Angle_y;
float degree_z = (180/pi)*Angle_z;


/* if(Angle_x<90.6)
//digitalWrite(enableA,HIGH);
//for(degree_x;degree_x>115;degree_x++)
{
digitalWrite(direction1,LOW);
digitalWrite(direction2,HIGH);
// digitalWrite(enable,HIGH);
//delay(8 );
digitalWrite(enableA,HIGH);
digitalWrite(enableB,HIGH);
delay(500);

digitalWrite(enableA,LOW);
digitalWrite(enableB,LOW);
delay(1000);

digitalWrite(direction2,LOW);
// Serial.print("degreeA=");
// Serial.println(degreeA,DEC);
}
*/

Serial.print("Angle_x = "); //Angle x in degrees
Serial.println(degree_x, DEC);
Serial.print("Angle_y = "); //Angle y in degrees
Serial.println(degree_y, DEC);
Serial.print("Angle_z = "); //Angle z in degrees
Serial.println(degree_z, DEC);
if(degree_x>refdegree)
{
// for(degree_x;degree_x>=refdegree;degree_x--)
present=degree_x;

error=present-refdegree;
PID = error*PTerm; // start with proportional gain
Accumulator += error; // accumulator is sum of errors
PID += ITerm*Accumulator; // add integral gain and error accumulation
PID += DTerm*(error); // differential gain comes next
//PID = PID>>Divider;
Serial.print("PID=");
Serial.println(PID,DEC);
for(error;error>=0;error--)
{
digitalWrite(direction1,LOW);
digitalWrite(direction2,HIGH);
// digitalWrite(enable,HIGH);
//delay(8 );
analogWrite(enableA,(PID));
analogWrite(enableB,(PID));
// delay(4);

// Serial.print("error=");
//Serial.println(error,DEC);
// analogWriMte(enableA,0);
// analogWrite(enableB,0);
digitalWrite(direction2,LOW);
digitalWrite(direction1,LOW);
}
analogWrite(enableA,0);
analogWrite(enableB,0);

}
else
{
errorB=refdegree-degree_x;
Serial.print("errorB=");
Serial.println(errorB,DEC);
Serial.print("presentB=");
Serial.println(presentB,DEC);
for(errorB;errorB>=0;errorB--)

//for(error;error<=0;error++)
{
digitalWrite(direction1,HIGH);
digitalWrite(direction2,LOW);
analogWrite(enableB,(160));
analogWrite(enableA,(160));
delay(4);
//digitalWrite(enableA,0);
//delay(HIGH0);
//analogWrite(enableB,0);
// analogWrite(enableA,0);



Serial.print("errorB=");
Serial.println(errorB,DEC);

}}
//delay(300);
analogWrite(enableB,0);
analogWrite(enableA,0);
digitalWrite(direction1,LOW);
digitalWrite(direction2,LOW);

//digitalWrite(enableA,LOW);
//igitalWrite(enableB,LOW);
}





so what all the changes do you think i should make to balance my robot,
and my robot is in horizontal chasis

Hello Anvesh,

I can really only help with your MSP430-related questions, you will have to find another avenue for help with your PID controller code.

Regards,
Ryan

>so what all the changes do you think i should make to balance my robot,
"here's my code, please fix it" approach usually does not work. Instead please try to test and debug your hardware/software, provide results. Then ask question, not command us to work for you by fixing your code.

p.s. I see that you use fixed point PID math and uncommented PID accumulator scaling code (PID>>Divider) at the end of the PID math. Why did you do that?! Such way you just totally destroy everything about intended fixed point PID math, PID accumulator goes skyhigh and no wonder it does not work.

You would want to read literature mentioned in this post and this post first. I did find them by searching "PID" in this forum search engine.