Introduction
This project explores a couple of ways of simulating and using a bar graph with the Arduino. Bar graph components like the following one can be used,
This type of bar graph is basically just 10 LEDs in a row with anodes on one side of the component and cathodes on the other.
The same thing can be created by just placing 10 LEDs on a breadboard. If you have LEDs smaller than 5mm, you may be able to get them closer together on the breadboard. If not, just space out as you see in the diagrams.
You Will Need
- 10 x LEDs or 1 x 10 Segement Bar Graph
- 10 x 330 Ohm Resistors
- 10K Trimmer Potentiometer
- 1 x Piezo Buzzer
Making The Circuit – Bar Graph
The first job is to connect up all of those LEDs and resistors to make the bar graph.
Programming The Arduino – Bar Graph
Here is some code to test that the bar graph has been wired correctly.
int ledPin[] = {1,2,3,4,5,6,7,8,9,10};
void setup()
{
for (int i =0;i<10;i++)
{
pinMode(ledPin[i], OUTPUT);
}
}
void loop()
{
upanddown();
delay(1000);
oneatatime();
delay(1000);
}
void alloff()
{
for (int i =0;i<10;i++)
{
digitalWrite(ledPin[i], LOW);
}
}
void allon()
{
for (int i =0;i<10;i++)
{
digitalWrite(ledPin[i], HIGH);
}
}
void showUpTo(byte numtoshow)
{
alloff();
for (byte i = 0;i<numtoshow;i++)
{
digitalWrite(ledPin[i],HIGH);
}
}
void upanddown()
{
for (int i =0;i<10;i++)
{
digitalWrite(ledPin[i], HIGH);
delay(100);
}
for (int i=9;i>=0;i–)
{
digitalWrite(ledPin[i], LOW);
delay(100);
}
}
void oneatatime()
{
for (int i =0;i<10;i++)
{
digitalWrite(ledPin[i], HIGH);
delay(100);
digitalWrite(ledPin[i], LOW);
delay(100);
}
}
Making The Circuit – Trimpot
Adding a trimpot to control the bar graph allows the bar graph to be used as an indicator for the position of the potentiometer.
For more detail: Using A Bar Graph With The Arduino
