Tag Archives: l298n

Raspberry Pi Robot #2

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I’ve connected the [amazon &title=Raspberry Pi&text=Raspberry Pi] to an L298N and two 6V DC Motors, which have been in the Makeblock Starter Kit. I’ve had some issues with the WPA2 Enterprise TLS Network, which is why there is an cable attached.

IMG_20140521_164828

I’ve also written a small geometry/Twist controller for ROS-compatibility,for controlling the robots movement with keyboard interop like I did before.

Before I dismantle this little robot, I’ve like to share a little video:
Youtube Video

As soon as possible I will use the arduino micro and the two 250rpm stepper motors – for that I am planning to use a Arduino Motor shield that I’ve already ordered.

Howto run a 12V bipolar stepper motor with arduino micro and L298N at 150rpm

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Today I experimented with a 12V bipolar stepper motor and the 5V arduino micro.

To get things working I’ve put the 9V from my six 1.5V Batteries into an UBEC which accelerates them to 12V at a loss of below 10% (at 350mAh) connected them to the VCC of the L298N and wired the 4 signal cables of the motors to it. Because thats a lot of numbers to keep track of – I’ve made a small video of the setup:

Youtube Video

Doing the math according to a wheel with 5,8cm heigth and 150rpm I’ve reached, my robot will be able to run about 1,6 km/h – this might be increased with a better motor driver like they used on the arduino motor shield. I’ve read they reached about 250 rpm on the same motor which would be 2,73km/h.

The code of the arduino is pretty simple:

#include <Stepper.h>

const int stepsPerRevolution = 200;  // change this to fit the number of steps per revolution
// for your motor


// init the stepper lib on pins 8 through 11:
Stepper myStepper(stepsPerRevolution, 8,9,10,11);            

void setup() {
  // nothing to do inside the setup
}

void loop() {
    myStepper.setSpeed(150);
    myStepper.step(stepsPerRevolution/100); 
}

 

Howto run two 6V DC motors with arduino micro

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So before trying to get the planned stepper motors running, I quickly put a dc motors setup together:

I’ve got two dc motors coming with my make block robot starter kit. And for research I also ordered a small l298n motor controller shield which is able to control motors up to 24Vs and 2A each by  4 small input wires at  for example 3,3V and 2 additional +5V motor enablers.

There is a nice little page which explains all states of the L298N according to the arduino micro here. For a [amazon &title=Raspberry Pi&text=Raspberry Pi] I found a nice Youtube video explaining everything here.

For me in the end both motors rotated quite nicely, like this video shows:

Youtube Video

For the micro I wrote this peace of code:

const int IN1 = 10;
const int IN2 = 11;
const int IN3 = 8;
const int IN4 = 9;

void setup()
{
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}
 
void loop()
{
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);  
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  
  //hold speed fro 5 seconds
  for(byte j = 5; j > 0; j--) 
  {
    delay(1000);
  }
  
  //stop for two seconds.
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);  
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
  delay(2000);
  
  //switching direction
  digitalWrite(IN1, LOW); 
  digitalWrite(IN2, HIGH);  
  digitalWrite(IN3, LOW); 
  digitalWrite(IN4, HIGH);
 

 //hold speed for 5 seconds
 for(byte u = 5; u > 0; u--)
  {
    delay(1000);
  }
}