Power issues in my Project!!!

Using Arduino Project Guidance
1

Hello everyone,
I'm working on an Arduino controlled RC Car. The problem with my project is that the motor does not run as fast as I expected. The wheels stop spinning as soon as I place the car on the floor. I'm using 4 AAA 1.5V batteries right now to power the whole system (Arduino, L298N, 2 DC Motors).
What should I do to solve this problem....Thanks in advance.

2

What happens when you leave out all the Arduino stuff, and power the motor directly from the batteries?

3

MohsinKamalAkbar:
I'm using 4 AAA 1.5V batteries right now to power the whole system

This being an Arduino forum, perhaps more to the point: what happens when you leave out all the motor stuff, and just address the Arduino?

Chances are good that it's not much, but nobody will know until you come forth with more information on how the power is applied, and what sort of Arduino you are using.

(Hint#1) Most Arduinos require an absolute minimum of 6v at the barrel jack and 4xAAA are not likely to deliver that for very long - even without the motors.

(Hint#2) Most Arduinos have an operating voltage of 5v. and 4xAAA are likely to be running at about 4.8v, so bypassing the regulators and feeding 5v direct isn't going to help

A voltmeter will reveal all but, if you don't have one, your money is probably better spent on a couple of extra AAAs, or making a better choice of battery altogether.

4

Use a modern motor driver. The L298N can consume as much as 4 volts internally. From 6 volts, that would leave only 2 volts for the motors.

5

The LEDs on arduino board (GREEN and ORANGE) and the LED on motor driver go reallyyy dim and the motors spin veryy slow. It feels as if they are not working...

6

What happens if you power the Arduino from the battery pack and run the Blink program ?

AAA batteries generally have a very low capacity and even if they work for a short while they are unlikely to provide the requisite voltage for long.

7

My son's RC car runs on 4 AA batteries and only has some 30 min to 1 hr play time before it gets slow. Also running it on carpet makes it slower. I think it is just insufficient power on your motors. Can you use AA batteries, even just for a test?

8

The motors work just fine without Arduino, Motor Driver, Bluetooth module on THE SAME BATTERIES I USED BEFORE!!!!

9

MohsinKamalAkbar:
The motors work just fine without Arduino, Motor Driver, Bluetooth module on THE SAME BATTERIES I USED BEFORE!!!!

Yes, but how much current are the Arduino, Motor Driver and Bluetooth module taking ?

You have posted no code so we don't even know how you are controlling the Motor Driver (presumably an H bridge, but is it ?). For all we know you are driving it with a 50% PWM signal thus reducing the motor speed.

More details of the devices, circuit and program please.

10

int in1 = 2;
int in2 = 4;
int s1 = 7;
int s2 = 8;
char hlight;
char d;
char ind;
void setup()
{
pinMode(in1, OUTPUT);
pinMode(in2, OUTPUT);
pinMode(10, OUTPUT);
Serial.begin(9600);
}

void loop()
{
d=Serial.read();
hlight = Serial.read();
if(d=='F')
{
digitalWrite(in1, HIGH);
digitalWrite(in2, LOW);
digitalWrite(11, LOW);
}
else if(d=='B')
{
digitalWrite(in1, LOW);
digitalWrite(in2, HIGH);
digitalWrite(11, HIGH);
}
else if(d=='G')
{
digitalWrite(s1, HIGH);
digitalWrite(s2, LOW);
digitalWrite(in1, HIGH);
digitalWrite(in2, LOW);
}
else if(d=='I')
{
digitalWrite(s1, LOW);
digitalWrite(s2, HIGH);
digitalWrite(in1, HIGH);
digitalWrite(in2, LOW);
}
else if(d=='L')
{
digitalWrite(s1, HIGH);
digitalWrite(s2, LOW);
}
else if(d=='R')
{
digitalWrite(s1, LOW);
digitalWrite(s2, HIGH);
}
else if(d=='J')
{
digitalWrite(s1, LOW);
digitalWrite(s2, HIGH);
digitalWrite(in1, LOW);
digitalWrite(in2, HIGH);
}
else if(d=='H')
{
digitalWrite(s1, HIGH);
digitalWrite(s2, LOW);
digitalWrite(in1, LOW);
digitalWrite(in2, HIGH);
}
else if(d=='S')
{
digitalWrite(in1, LOW);
digitalWrite(in2, LOW);
digitalWrite(s1, LOW);
digitalWrite(s2, LOW);
}
if(hlight=='W')
{
digitalWrite(10, HIGH);
}
else if(hlight=='w')
{
digitalWrite(10, LOW);
}
}

11 
void loop()
{
  d = Serial.read();
  hlight = Serial.read();

How do you know that there is anything to read, let alone 2 bytes ?

12

MohsinKamalAkbar:
The motors work just fine without Arduino, Motor Driver, Bluetooth module on THE SAME BATTERIES I USED BEFORE!!!!

Does the motor work with the h-bridge?

Here's my L298N tutorial.

You can test the h-bridge section without the Arduino.

As others have pointed out, the L298N drops the voltage supplied to the motor.

The motor supply voltage of the L298N is supposed to be 2.5V higher than the voltage used to control the logic. I've found the L298N will generally work with less than the specified voltage but it seems like a good idea to follow the driver's specs.

How is your h-bridge circuit controlled? I see four control pins in the code. Can you control direction with a single pin? Most L298N boards have two direction control pins and one speed control pin per motor.

And why did you yell at us?

13