> For the complete documentation index, see [llms.txt](https://sharinghub-eng.kittenbot.hk/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sharinghub-eng.kittenbot.hk/educational-kit-sets/futureboard-iot-education-kit/futureboard-iot-education-kit-instructions/laser-distance-ruler.md).

# Laser Distance Ruler

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/distance_measure.jpg)

A ruler using a TOF sensor.

### Building Instructions

[Building Instructions(Right Click->Save As)](https://github.com/kittenbothk/kittenbothk/raw/master/Kits/future_inventor/instructions/pdf/laser_ruler.pdf)

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/ruler_wire.png)

### Sample Wiring Diagram

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/ruler_wire.png)

### Sample Program

#### KittenBlock Sample Program

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/ruler_code.png)

[Download Sample Program(Right Click->Save As)](https://github.com/kittenbothk/kittenbothk/raw/master/Kits/future_inventor/instructions/sb3/laser.sb3)

#### Python Sample Program

```
#/bin/python

from future import *
from sugar import *

y = 0
y1 = 0
y2 = 0
x = 0


def valmap(x, in_min, in_max, out_min, out_max):
    return int((x-in_min) * (out_max-out_min) / (in_max-in_min) + out_min)


def baseline():
  global y,y1,y2,x

  screen.line(77,10,82,10,(0, 255, 0))
  screen.line(77,25,82,25,(0, 255, 0))
  screen.line(77,40,82,40,(0, 255, 0))
  screen.line(77,55,82,55,(0, 255, 0))
  screen.text(str('0'),63,5,1,(0, 255, 0))
  screen.text(str('30'),58,20,1,(0, 255, 0))
  screen.text(str('60'),58,35,1,(0, 255, 0))
  screen.text(str('90'),58,50,1,(0, 255, 0))
  y = (valmap(sensor.pitch(), 0, 90, 55, 10))
  screen.line(80,y,210,y,(255, 0, 0))



screen.sync = 0

while True:
  if Button("P1").value() == 0:
    screen.fill((0, 0, 0))
    baseline()
    x = TOFDistance().value()
  if x > 1000:
    screen.textCh(x,15,80,3,(0, 119, 255))
  else:
    if x < 100:
      screen.textCh(x,45,80,3,(0, 119, 255))
    else:
      screen.textCh(x,30,80,3,(0, 119, 255))
  screen.refresh()
```

[Download Sample Program(Right Click->Save As)](https://github.com/kittenbothk/kittenbothk/raw/master/Kits/future_inventor/instructions/py/laser.py)

### Program Instructions

Press the button, the Futureboard will display the distance measured.


---

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