Created November 29, 2015

Sharp Infrared Distance Sensor - 11/30/15

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Things used in this project

Hardware components

Arduino UNO

sharp infrared distance sensor

Story

Sharp Infrared Distance Sensor (2Y0A21YK)

Wiring Schematic and Setup

Wiring Schematic for the Sharp Infrared Distance Sensor

Physical Setup for the Sharp Infrared Distance Sensor

Software and Code

Inspiration was found by researching online where I found this useful tutorial which explained an Arduino coding setup:

http://communityofrobots.com/tutorial/kawal/how-use-sharp-ir-sensor-arduino

Arduino Code for the Sharp Infrared Distance Sensor

What is the Effective Range of Operation:

The answer to this question was also found by researching online and pulling up the datasheet for this particular product. In the end, I found three different datasheets, but all of them appear to agree with one another and indicate that the effective range was 10 to 80cm. Although there were various documents, they all seem to verify one another.

http://www.sharpsma.com/webfm_send/1489

https://www.sparkfun.com/datasheets/Components/GP2Y0A21YK.pdf

http://www.sharpsma.com/webfm_send/1208

1 / 3 • Sharp Infrared Distance Sensor Datasheet

What Happens if an Object is Closer Than the Shortest Distance:

Based on the plots provided in the datasheet, it appears that the Distance vs Voltage plot follows an exponentially decaying curve within the suggested range of 10 to 80cm, When plotting inverse distance vs voltage, this represents an friendly almost linear relationship.

However, going back to the distance vs voltage plot, it seems that the output voltage will suddenly change behavior and sharply decrease as the object moves closer than 10cm to the sensor. This will also cause the inverse distance vs voltage behavior to deviate from its linearity.

1 / 2 • Inverse Distance vs Voltage Plot for the Sharp Infrared Distance Sensor Datasheet

AnalogRead() Values at 20, 40, 60 and 80 cm From the Sensor

AnalogRead() values were taken by looking at the serial monitor while the Arduino program was run from my laptop computer. Distances were measured using a standard 1 foot ruler with cm markings and a white infrared reflective paper was placed perpendicularly at the desired distances.

Setup for Documenting analogRead() Values at Specific Distances

The results can be found tabulated below along with a plot of distance vs analogRead() values. Most notably we find what resembles an exponentially decaying relationship with an R-squared value of 0.985 between distance and our experimental analogRead() values. This seem to fall perfectly in line with the behavior predicted above in the datasheets.

Distance vs analogRead() Values Plot

Code

Untitled file

int sensorpin = 0;                 // analog pin used to connect the sharp sensor
int val = 0;                 // variable to store the values from sensor(initially zero)

void setup()
{
  Serial.begin(9600);               // starts the serial monitor
}
 
void loop()
{
  val = analogRead(sensorpin);       // reads the value of the sharp sensor
  Serial.println(val);            // prints the value of the sensor to the serial monitor
  delay(100);                    // wait for this much time before printing next value
}

Credits

Jimmy Huang

16 projects • 9 followers

Sharp Infrared Distance Sensor - 11/30/15

Things used in this project

Hardware components

Story

Sharp Infrared Distance Sensor (2Y0A21YK)

Wiring Schematic and Setup

Software and Code

What is the Effective Range of Operation:

What Happens if an Object is Closer Than the Shortest Distance:

AnalogRead() Values at 20, 40, 60 and 80 cm From the Sensor

Schematics

Wiring Schematic

Code

Untitled file

Credits

Jimmy Huang

Comments

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Sharp Infrared Distance Sensor - 11/30/15

Sharp Infrared Distance Sensor - 11/30/15

Things used in this project

Hardware components

Story

Sharp Infrared Distance Sensor (2Y0A21YK)

Wiring Schematic and Setup

Software and Code

What is the Effective Range of Operation:

What Happens if an Object is Closer Than the Shortest Distance:

AnalogRead() Values at 20, 40, 60 and 80 cm From the Sensor

Schematics

Wiring Schematic

Code

Untitled file

Credits

Jimmy Huang

Comments

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