BitBotXL light sensors

Using the buzzer

The buzzer is connected to pin0.

Turn it on using: pin0.write_digital(1).

Turn it off using: pin0.write_digital(0).

To turn on the buzzer for a specific time, put in a sleep between turning it on and turning it off. The code below has a sleep of 1000ms, so that the buzzer is on for 1 sec.

from microbit import *

pin0.write_digital(1)
sleep(1000)
pin0.write_digital(0)

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Tasks

1. Write code to turn on the buzzer for half a second.

2. Write code, using a for-loop, to make 3 half second buzzer sounds with 1 second between each of them.

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Refactoring into a class

The class, class BitBotXLBuzzer(), is used to group the code related to the buzzer.

The code to drive the buzzer is placed in a function, buzz.

The function will have a parameter, duration, which sets the duration of the buzzer.

This should also simplify the buzzer use. e.g. buzz(1000).

Firstly, the code above is placed inside a function.

The sleep value is replaced with the duration variable.

The duration parameter is added to the definition line: def buzz(duration):.

The self parameter must be included first for a regular method in a class.

Instead of def buzz(duration):, def buzz(self, duration): is required.

class BitBotXLBuzzer():

    def buzz(self, duration):
        """Sound a buzz for duration milliseconds."""
        pin0.write_digital(1)
        sleep(duration)
        pin0.write_digital(0)

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Using the class

class BitBotXLBuzzer

Set up the buggy’s buzzer for use.

Use buzzer = BitBotXL.BitBotXLBuzzer() to use the buggy’s buzzer.

The code below imports the BitBotXL module and sets up the buzzer.

from microbit import *
import BitBotXL


# setup the buzzer
buzzer = BitBotXL.BitBotXLBuzzer()

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Using the buzz method

buzz(duration)

Activates the buzzer for the specified duration in milliseconds.

The code below, uses buzzer.buzz(duration) to make a buzz.

from microbit import *
import BitBotXL


# setup the buzzer
buzzer = BitBotXL.BitBotXLBuzzer()

buzzer.buzz(1000)

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Tasks

1. Write code using a while True loop to make a 500ms buzz every 2 seconds.

2. Write code using a for-loop to make buzz sounds of 100, 200, 300 and 400ms separated by a 500ms sleep.

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28 0x1c r 114 01110010 s 115 01110011

x << y Returns x with the bits shifted to the left by y places (and new bits on the right-hand-side are zeros). This is the same as multiplying x by 2**y.

x & y Does a “bitwise and”. Each bit of the output is 1 if the corresponding bit of x AND of y is 1, otherwise it’s 0.

value_left = i2c.read(__I2CADDR1, 1)[0] value_right = i2c.read(__I2CADDR2, 1)[1] print(value1, value2) # , (value0 & 2), (value0 & 1)) # print(1 << 1, 1 << 0) #, 2, 1 sleep(1000

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def getLine(bitval):

mask = 1 << bitval value = 0 try:

print(i2c.read(I2CADDR, 1)) if bitval == 0:

value = i2c.read(I2CADDR, 1)[0] print(0, value, mask, (value & mask))

elif bitval == 1:

value = i2c.read(I2CADDR, 2)[1] print(1, value, mask, (value & mask))

except OSError:

pass

if (value & mask) > 0:

return 1

else:

return 0