# SharpIR
Arduino Infra Red Sharp Lib

Based on an original work of Dr. Marcal Casas-Cartagena .

 1. Perform 25 reading of analog pin (Nb samples can be changed in .h)
 2. Sort values
 3. Convert median value to cm

# Usage

- #include \<SharpIR.h\>
- SharpIR sharp(ir_analog_pin, model);
- int dist = sharp.distance();

Model : 
- GP2Y0A02YK0F --> "20150"
- GP2Y0A21YK --> "1080"
- GP2Y0A710K0F --> "100500"
- GP2YA41SK0F --> "430"

# Sharp IR Volt Centimeter conversion

## GP2Y0A02YK0F
### Model: "20150" [20cm to 150cm]

| Volt | Distance |
| ---- | -------- |
| 2,8 | 15 |
| 2,5 | 20 |
| 2 | 30 |
| 1,55 | 40 |
| 1,24 | 50 |
| 1,05 | 60 |
| 0,905 | 70 |
| 0,82 | 80 |
| 0,7 | 90 |
| 0,66 | 100 |
| 0,6 | 110 |
| 0,55 | 120 |
| 0,5 | 130 |
| 0,455 | 140 |
| 0,435 | 150 |

Using MS Excel, we can calculate function (For distance > 15cm) :

Distance = 60.374 X POW(Volt , -1.16)

## GP2Y0A21YK 
### Model: "1080" [10cm to 80cm]

| Volt | Distance |
| ---- | -------- |
| 2,6 | 10 |
| 2,1 | 12 |
| 1,85 | 14 |
| 1,65 | 15 |
| 1,5 | 18 |
| 1,39 | 20 |
| 1,15 | 25 |
| 0,98 | 30 |
| 0,85 | 35 |
| 0,75 | 40 |
| 0,67 | 45 |
| 0,61 | 50 |
| 0,59 | 55 |
| 0,55 | 60 |
| 0,5 | 65 |
| 0,48 | 70 |
| 0,45 | 75 |
| 0,42 | 80 |

Using MS Excel, we can calculate function (For distance > 10cm) :

Distance = 29.988 X POW(Volt , -1.173)

## GP2D12_24
###   Model: "1081" [10cm to 80cm]

|  Volt | Distance |
| ----- | -------- |
| 2.534 | 10       |
| 1.391 | 20       |
| 0.952 | 30       |
| 0.727 | 40       |
| 0.581 | 50       |
| 0.493 | 60       |
| 0.483 | 70       |
                               
                               
                               
                               
                               
Based on   https://mycurvefit.com/ :
 
Distance = 24.65251/(Volt-0.1065759)
 
## GP2Y0A710K0F
### Model: "100500" [100cm to 500cm]



Based on the SHARP datasheet we can calculate the linear function: 
`y = 137500x + 1125` 
which gives us: 
`1 / ((Volt - 1125) / 137500) = distance_in_cm`
(For distance > 100cm)

## GP2YA41SK0F ( <=> GP2D120 )
### Model: "430" [4cm to 30cm]

Based on the SHARP datasheet we can calculate the function (For distance > 3cm) :

Distance = 12.08 X POW(Volt , -1.058)