# Programming with MicroPython: Onboard Sensors

### Import FutureBoard Library

Import the Library to make use of its functions.

```
from future import *
```

### 02: Onboard Sensors

#### 1. Buttons

```
sensor.btnValue(btn)
```

Parameter btn represents A or B button, accepted values are a, b.

#### 2. Light Sensor

```
sensor.getLight()
```

Returns a value 0\~4095.

#### 3. Temperature Sensor

```
sensor.getTemp()
```

Returns a degree in Celsius, FutureBoard can measure temperatures from -40 to 80 degrees.

#### Sample Program for 1\~3

```
from future import *

from time import sleep

screen.fill((0, 0, 0))
while True:
  if sensor.btnValue('a'):
    screen.text(str("Light: ")+str(sensor.getLight()),5,10,1,(0, 119, 255))
    sleep(0.5)
  if sensor.btnValue('b'):
    screen.text(str("Temp: ")+str(sensor.getTemp()),5,30,1,(0, 119, 255))
    sleep(0.5)
```

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/python15.gif)

***

#### 4. Accelerometer

```
sensor.accX()
sensor.accY()
sensor.accZ()
```

Returns the accelerometer value of the 3 axis with G as the unit.

#### 5. Tilt Angles

```
sensor.roll()
sensor.pitch()
```

Returns the roll and pitch angle of the FutureBoard.

#### Sample Program for 4\~5

```
#The screen displays the readings of the accelerometer.

from future import *

from time import sleep

screen.sync = 0
while True:
  screen.fill((0, 0, 0))
  screen.text(str("X: ")+str(sensor.accX()),5,10,1,(0, 119, 255))
  screen.text(str("Y: ")+str(sensor.accY()),5,25,1,(0, 119, 255))
  screen.text(str("Z: ")+str(sensor.accZ()),5,40,1,(0, 119, 255))
  screen.text(str("Roll: ")+str(sensor.roll()),5,55,1,(0, 119, 255))
  screen.text(str("Pitch: ")+str(sensor.pitch()),5,70,1,(0, 119, 255))
  screen.refresh()
  sleep(0.2)
```

***

#### 6. Gesture Detection

```
sensor.gesture(gesture)
```

8 kinds of gesture can be detected by the FutureBoard.

1. ‘shake’
2. ‘freefall’
3. ‘tilt\_up’
4. ‘tilt\_down’
5. ‘tilt\_left’
6. ‘tilt\_right’
7. ‘face\_up’
8. ‘face\_down’

#### 7. Gesture Event Trigger

```
sensor.gesTrig[ges] = fn
sensor.startSchedule()
```

#### Sample Program for 6\~7

```
# Futureboard plays a melody on shake.
# Futureboard shows the status of gestures face up and face down.

from future import *

from time import sleep

def onGesture_shake():
  buzzer.melody(JUMP_UP)

sensor.gesTrig['shake']=onGesture_shake
sensor.startSchedule()

screen.sync = 0
while True:
  screen.fill((0, 0, 0))
  screen.text(str("Face Up: ")+str(sensor.gesture('face_up')),5,10,1,(0, 119, 255))
  screen.text(str("Face Down: ")+str(sensor.gesture('face_down')),5,25,1,(0, 119, 255))
  screen.refresh()
  sleep(0.2)
```

***

#### 8. Compass Calibration

```
calibrateCompass()
```

Magnetometer and compass requires calibration before using.

#### 9. Magnetic Strength

```
sensor.magX()
sensor.magY()
sensor.magZ()
sensor.magStrength()
```

Returns the magnetic strength detected by the sensor with uT as the unit.

#### 10. Compass Bearing

```
sensor.heading()
```

Returns the compass bearing.

#### Sample Program for 8\~10

```
# Simulates a compass

from future import *
import math
calibrateCompass()
screen.sync = 0
ds = ''
while 1:
    d = int(math.fabs(360-sensor.heading()))
    screen.fill(44)
    if (d<20) | (d>340):
        ds = 'N'
    elif (d<70):
        ds = 'NE'
    elif (d<110):
        ds = 'E'
    elif (d<160):
        ds = 'SE'
    elif (d<200):
        ds = 'S'
    elif (d<250):
        ds = 'SW'
    elif (d<290):
        ds = 'W'
    else:
        ds = 'NW'
    screen.text(d, 5,5)
    screen.textCh(ds,5,30)
    screen.text(str('Strength: ')+str(sensor.magStrength()),5,80)
    screen.refresh()
```