#Discovery Bot API

The Discovery Bot

The discovery bot is a fun and simple raspberry pi robot for all ages. This project allows you to easily control your robot through a python API. This project is required for the discovery blockly project.

The API is dived into simple classes and modules used to control different aspects of the discovery bot.

Download Disovery Bot Image

Get the latest image for the discovery bot for your raspberry pi

http://images.discoverykit.org/DiscoveryBot/stable/

Using the API in your python project

Import the whole discovery API into your project import discovery_bot

You can also import only the modules that you need (e.g. movement) from discovery_bot import Movement

Movement

Create an instance of the movement class

import discovery_bot
robot = discovery_bot.Movement()

Asynchronous (non-blocking) control

robot.forward()     # Move forward at 100% speed
robot.forward(100)  # Move forward at 100% speed
robot.left(40)      # Turn left at 40% speed
robot.right(50)     # Turn right at 50%
robot.backward(90)  # Move back at 90% speed
robot.stop()        # Stop the robot
robot.move(100, 40) # Move the left wheel at 100% and the right wheel at 40%
robot.move(-50, 10) # Move the left wheel backwards at 50% speed and the right wheel at 10% speed

Synchronous (blocking) control

robot.forward(90, 5)    # Move forward for 5 seconds
robot.left(50, 1.5)     # Turn left for 1.5 seconds
robot.move(100, 10, 5)  # Move left motor at 100% and the right wheel at 10% for 5 seconds

Ultrasound

The ultrsound provides functions to read the distance of objects to the front of the robot. You can get a relative value from 0-100 or a rough value in centimeters.

from discovery_bot import Ultrasound
usound = Ultrasound()
usound.read()    # Get a normalized value between 0-100
usound.distance  # Returns a rough distance in CM

Camera

The camera class projects a means to set the angle on the camera mount as well as some basic functions for controlling the discovery bots camera.

from discovery_bot import Camera
camera = Camera()
camera.angle(90)    # Set the angle of the camera servo, between 0 - 120
camera.capture()    # Capture a picture with the camera and save to filesystem

Servo

This is the base class for all servos connected to the discovery bot. Using this class you can controll any servo connected to one of the four servo ports on the discovery bot.

import discovery_bot
from discovery_bot import Servo
servo0 = Servo(discovery_bot.pins.SERVO_0)
left = Servo(discovery_bot.pins.SERVO_LEFT_MOTOR)
servo0.set_normalized_speed(100)  # Treat servo as continous and provide a speed value
servo0.set_normalized_angle(90)   # Standard servo and provide angle 0 - 120
servo0.set_normalized(1200)       # Provide a pulse width to servo

Line Sensor

import discovery_bot
sensor = discovery_bot.LineSensor(discovery_bot.pins.LINE_SENSOR)
sensor.on_line()    # Return true if line detected
sensor.off_line()   # Return true if no line detected
sensor.last_state() # Remember the last known state of the sensor

IO

Base class for all GPIO based operations

import dicovery_bot
from discovery_bot import IO
gpio = IO(discovery_bot.pins.BUZZER)
gpio.on()
gpio.on_for(1) # Turn on for 1 second
gpio.off()
gpio.is_high()
gpio.is_low()