Scratch 3 that microbit

The Beta version of Scratch 3 (https://scratch.mit.edu/microbit) allows certain physical computing devices to interact with the Scratch; including the micro:bit. This post looks at a little experiment with the micro:bit; producing a pen that moves around the screen controlled by tilting a micro:bit.




Set-up
In the video above an example of the pen moving under micro:bit control is shown. Also, some discussion of setting up Scratch to work with the micro:bit is included. The best source for the instructions to set up the micro:bit/Scratch combination and the links needed is https://scratch.mit.edu/microbit. The key features are:
- The programming of the Micro:bit via Scratch is not done by downloading a new .hex file each time as you do with the python or the javascript blocks but is done through the Scratch Link which has to be run separately to the Scratch editor each time you have a session using Scratch and the Micro:bit. There is a version for both windows and OS X.
- One program/hex file is downloaded on to the micro:bit to form the link between the micro:bit and scratch.


Microbit and Pens
The experiment was to get a micro:bit to control a pen around the screen and draw (the video above shows the pen moving around under micro:bit control but not drawing).

The key to all of this the little blue icon at bottom left of the editor; this allows extra blocks/features to be added. You first need to connect a micro:bit; click on the blue icon and select the micro:bit option and attach a micro:bit to your machine, the system should (hopefully) allow you to make a connection. As well as the micro:bit blocks you will need to add the pen blocks via the blue icon and the pen option.

The code (see below) does two basic things
- Press button B on the micro:bit resets the pen to a fixed starting point;
- Tilting the micro:bit forwards and backwards (once the green flag has been pressed) moves the pen forward or backwards in the direction that the pen is facing and tilting left or right turns the pen.

At the moment the pen is drawing as if the nib is in the middle of the pen (see below) but tilting the micro:bit does give rough control. It is fun, to mix Scratch and micro:bit.

All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

MSc meets Micro:Bit

I have recently been teaching a module on Internet Programming on a MSc Computing programme (see related links), and was looking for a way to introduce a little bit of physical computing to finish of the module - micro:bits offer a route.

So a bit of context; most of the students on the module had first degrees in either networking or software engineering; so before they start the module they are competent in programming with Javascript, HTML, CSS and PHP. Therefore the module looked to develop new areas such as introductory blockchain,  virtual reality via the web (e.g. WebVR), using social media sources; but lastly looking at physical computing leading to an insight into the Internet of Things (IoT). As part of this last topic gaining some experience of programming and very simple networking was looked at using the micro:bit.

An activity was produced where:

• they, in pairs, initially replicate some code and work out how it worked;
• they then took the code and experimented with their own ideas.

In all cases they had to produce something that allowed doing something on one micro:bit, caused another micro:bit to do something in response.

Initially, javascript blocks (as above) were used and some students stuck with the graphical blocks, others moved into the text-based version. As far as the activity went it didn't matter; the main goals were to see the programming of a physical device via a web interface; to break a little mystique that it is as ways much harder to program physical devices and to get a bit of very simple networking going on.

Many of the students, started to investigate getting sounds to play on headphones and getting one micro:bit to trigger the other to play. One group went and started playing with python. 

Reflection bit - If I had similar, competent group again I would start this earlier; the level of engagement seemed high and the activities could then start developing towards IoT. Though, I admit to a bias for physical computing, it is appropriate in HE teaching; even using tools primarily designed for schools like the micro:bit.


Related Links
MSc Computing
MSc Computing (Computer Network Engineering)
MSc Computing (Software Engineering)



All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

Microbit Neuron - producing a single neuron using a microbit

This post is in response to a question from Carl Simmons (@Activ8Thinking) about has anyone built a microbit simple neuron.


Quick Overview

• Inputs are going to be binary
• Weighted sum is bias+W1*input1+w2*input2
• If weighted sum>=0 then the output is True (T on the LEDs) or '1'
• If weighted sum<0 then the output is False (F on the LEDs) or '0'

First attempt - A simple gate using the buttons A and B
So first attempt uses the A and B buttons on the Microbit as the two inputs and it produces T for true and F for false on the LEDs. So the weights produce an AND if the bias is changed from -2 to -1 you get an OR.

More Physical Solution for Single Neuron

So in this case the buttons are removed and P0 and P1 formed the inputs the weights are the same as in the previous example with the bias of -2 being used to produce a AND gate. Programming-wise this is a simpler solution than the previous one, no converting button presses into inputs.

Figures below show the 'neuron' in action.

First, one shows the case when both inputs are '0' ie. not connected to 3v connection. The output is False (F on the LEDs)

This figure shows when only one input is '1', the output is False.

Finally what happens when both inputs are '1', the output goes to True (T on the LEDs).

Where next?
Adapting the code so it produces a digital output and then combining them into a small network to solve a problem that a single neuron can't do the Exclusive OR (XOR).



All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

Gesture controlled python robot unicorn (or is it a rhino)

In the previous two post I built and played with a robot unicorn from Do it Kitshttps://doitkits.com/product/robot-unicorn/. In the first post, python was used to get it to move forward, backwards, left, right and stop. The second post discussed using a second microbit to send the movement instructions via the microbit's  radio module.

This post looks at extending the idea to using the accelerometer to pick up directions and send them to the robot unicorn (that still seems weird to write). Microbit's accelerometers, using the x and y directions, provide the inputs and then send the direction commands. The robot unicorn code is the same in the second post, the new code for the gestures is shown below. 




This a work in progress it detects x and y changes together so it does have a tendency to do one direction and then the other. This needs further work.

All my code for the robot unicorn projects can be found at: https://github.com/scottturneruon/Robo_unicorn_python or if you want to cite it : Turner, S., 2017. Robo_unicorn_python. Available at: <Robo_unicorn_python> https://doi.org/10.6084/m9.figshare.5729583.v7

All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

Robot Unicorn, python and a microbit

Yesterday (21/12/2017) I took delivery of a Robot Unicorn kit - now those were three words I don't think I would ever write let alone say from Do it Kits https://doitkits.com/product/robot-unicorn/ based around the microbit.

There is a fantastic video produced by Do It Kits on how to put the kit together and another on programming using Blocks:



Using the second video as a starting point I have produced my version of it in Python (see below). Essentially go forward, backwards, turn left and turn right, as well as pause.

I have probably wired it up back to front, so my settings in the code are the other way around to the ones used in the video - you may need to swap backwards and forwards around; as well as left and right.


This is a cute kit. How can anyone resist a Robot Unicorn?

All of the code available at Turner, S., 2017. Robo_unicorn_python. Available at: <Robo_unicorn_python> https://doi.org/10.6084/m9.figshare.5729583.v7

All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

kitronik :Move mini buggy (Python control of LEDs)

In two previous posts I looked at control the :Move buggy using JavaScript Blocks or Python. In this post we are going to look at controlling the LEDs using Python (or more accurately micropython).

Pin 0 controls the LEDs, they are based on5  NeoPixel compatible, RGB, addressable LEDs; so the Neopixel protocols (and library for Neopixels) can be used. 

Code First five colours of the rainbow. The array lig holds the RGB settings for the rainbow colours (more details on the RGB colours can be found at Lorraine Underwood's Halloween Cloud project). In the code below, the five LEDs have a different colour allocated to them.

from microbit import *
import neopixel

np = neopixel.NeoPixel(pin0, 5)
lig=[[255,0,0],[255,127,0],[255,255,0],[0,255,0],[0,0,255],[75,0,136],[139,0,255]]
while True:
    np[0] = lig[0]
    np[1] = lig[1]
    np[2] = lig[2]
    np[3] = lig[3]
    np[4] = lig[4]

    np.show()


Code to cycle through the rainbow
from microbit import *
import neopixel

np = neopixel.NeoPixel(pin0, 5)
lig=[[255,0,0],[255,127,0],[255,255,0],[0,255,0],[0,0,255],[75,0,136],[139,0,255]]
count1=1
count0=0
count2=2
count3=3
count4=4
while True:
        np[0] = lig[count0]
        if count0>=6:
            count0=0;
        else:
            count0=count0+1
        np[1] = lig[count1]
        if count1>=6:
            count1=0;
        else:
            count1=count1+1
        np[2] = lig[count2]
        if count2>=6:
            count2=0;
        else:
            count2=count2+1
        np[3] = lig[count3]
        if count3>=6:
            count3=0;
        else:
            count3=count3+1
        np[4] = lig[count4]
        if count4>=6:
            count4=0;
        else:
            count4=count4+1
        np.show()

        sleep(500)


All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

kitronik :Move buggy (Python controlled servos)

In a previous post I looked at controlling the Kitronik :Move buggy using Javascript based blocks. In this short post I will show controlling the servos of the micro:bit based :Move buggy with Python.

Control is via pin1(left motor) and pin2 (right motor) and the motors have to be driven in opposite directions to move forward or backwards. The direction of the motors is controlled by the analogue value written to the pins; pinX.write_analog(180) - anticlockwise or pinX.write_analog(1) - clockwise (pinX.write_analog(0) - stops the motor). Setting the analog_period seems to work at 20ms; this was found by experiment, discussed in a previous post.

So the initial code below sets up the moves for forward, backward, turn left, turn right all controlled with a move for so many milliseconds.

Code 
from microbit import *

pin1.set_analog_period(20)
pin2.set_analog_period(20)

def forward(N):
    pin1.write_analog(180)
    pin2.write_analog(1)
    sleep(N)
    
def backward(N):
    pin1.write_analog(1)
    pin2.write_analog(180)
    sleep(N)

def turnLeft(N):
    pin1.write_analog(1)
    pin2.write_analog(1)
    sleep(N)

def turnRight(N):
    pin1.write_analog(180)
    pin2.write_analog(180)
    sleep(N)

while True:
    forward(1500)
    backward(1500)
    turnLeft(1500)
    turnRight(1500)   

I would recommend running the :Move buggy on a surface that isn't smooth, I found the wheels slipping on a smooth surface. This is a really nice little robot to play with.

All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

kitronik :Move mini buggy (JavaScript blocks)

Finally got around to building add playing with the Kitronik :Move https://www.kitronik.co.uk/5624-move-mini-buggy-kit-excl-microbit.html (see below - I decided to put the green sides on the outside - just to be different). One of its features is a vertical set of holes for a pen to be placed in.

Add the blocks (found at https://github.com/KitronikLtd/pxt-kitronik-servo-lite) in blocks editor (https://makecode.microbit.org/) to control the motors. You can do the same thing with writing to the pins, those instructions come with the build instructions, but using the extra blocks  is a little easier to understand. Also add the package for neopixels (type in neopixels in the search box to find them). Two very good tutorials I found useful to start with can be found at:

• Neopixels on the robot  in blocks - https://www.kitronik.co.uk/blog/using-kitronik-zip-leds-bbc-microbit/
• Servos on the robot in blocks - https://www.kitronik.co.uk/blog/kitronik-custom-pxt-editor-servo-blocks/

1. Motor example
I wanted it so that press A on the Micro:bit the robot goes turns right, goes forward, goes back and turns left. 

A stop block does need to be included, without it the :Move will continue moving. The wheels I found can slip on some surfaces reducing the precision, but still fun to play with.

2. At the start and stopping.
I want to use the motors and the 'pixels', but I want to have a known starting position for the motors and set the turning speed; this was possible using the blocks (see below). The pixels are set at this point on pin P0 (see below) as well. 

To stop both the motors and cycling of the pixels - pressing buttons A+B together was set up to this.

3. Rainbow on the pixels.

On pressing button B the pixels rotate through a range of colours.

4. Summary
This is great fun. Having the set of blocks adding for the servos means it is a bit simpler to work with. 

All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

Micro:bit, PXT, Micro:pixel and Rainbows

Continuing to play with PXT (http://pxt.microbit.org) and the Micro:bit, I wanted to try this in combination with a Proto-Pic Micro-pixel board with its 32 neopixel LEDs.

The routine (shown in the screenshot below) use the Neopixels package (use the add package option on the menu to add it) to do two things:

• On pressing button B - cycle through the colours and shift the colour to the next pixel producing a shifting pattern.
• On pressing button  A - the pixels are cleared one by one.

Code is shown above, and thank you to Jonathan "Peli" de Halleux (@pelikhan) for pointing out the redundant code I had left in, it is appreciated.

The video below shows the system in action:




You can try the code out in the simulator below:

All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

Neuron Controlled Edge follower updated

In the last post experimentation with an artificial neuron controlling the Bit:Bot to follow the edge of a line (it follows the left-hand side of the line).

More details can be found in the previous post.The neurons (well two separate ones, S1 and S2) are produced using weighted sums - summing the weights x inputs [ right-hand sensor (rs) and left-hand sensor (ls)] plus a bias for each neuron in this case w[0] and w[3].
    net=w[0]+w[1]*rs+w[2]*ls      
    net2=w[3]+w[4]*rs+w[5]*ls


If weighted sum >=0 then its output 1 otherwise 0


What actual causes S1 to be either 1 or 0 is all defined by a set of weights w (three for the first neurone, S1,  three for S2).

w=[0,-1,1,-1,1,-1]


Modifications to the code in the last post have been around fine tuning the values in converting the outputs of the two neurons S1 and S2 into actions as shown below.
    if s1==1 and s2==1:
        forward(20)   
    elif s1==0 and s2==1:
        forward(15)
        right_turn(25)
    elif s1==1 and s2==0:
        forward(15)
        left_turn(25)       
    elif s1==0 and s2==0:
        backward(5)

The functions for forward, right_turn, etc are defined elsewhere.


To change the function of the system, change the values in wThe complete code is shown below.


Code
from microbit import *
import neopixel, random, array

w=[]  

def forward(n):
    pin0.write_analog(551)
    pin8.write_digital(0) 
    pin1.write_analog(551)
    pin12.write_digital(0)
    sleep(n)
    
def backward(n):
    pin0.write_analog(551)
    pin8.write_digital(1) 
    pin1.write_analog(551)
    pin12.write_digital(1)
    sleep(n)
    
def right_turn(n):
    pin0.write_analog(511)
    pin8.write_digital(0) 
    pin1.write_analog(511)
    pin12.write_digital(1)
    sleep(n)
    
def left_turn(n):
    pin0.write_analog(551)
    pin8.write_digital(1) 
    pin1.write_analog(551)
    pin12.write_digital(0)
    sleep(n)
       
w=[0,-1,1,-1,1,-1]

while True:
    ls= pin11.read_digital()
    rs= pin5.read_digital()
    
    net=w[0]+w[1]*rs+w[2]*ls
    net2=w[3]+w[4]*rs+w[5]*ls

    if net>=0:
        s1=1
    else:
        s1=0

    if net2>=0:
        s2=1
    else:
        s2=0
   
    if s1==1 and s2==1:
        forward(20)   
    elif s1==0 and s2==1:
        forward(15)
        right_turn(25)
    elif s1==1 and s2==0:
        forward(15)
        left_turn(25)       
    elif s1==0 and s2==0:
        backward(5)


Video of it in action:






Please feel free to use the code and improve on it, and I would especially welcome the seeing the improvement through the comments.



All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon

4Tronix Bit:Bot Neuron Controlled Edge follower

In the last post I was playing with 4Tronix's Bit:Bot. In this post I will show the initial experimentation with an artificial neuron controlling the Bit:Bot to follow the edge of a line (it follows the left-hand side of the line).

The neurons (well two separate ones, S1 and S2) are produced using weighted sums - summing the weights x inputs [ right-hand sensor (rs) and left-hand sensor (ls)] plus a bias for each neuron in this case w[0] and w[3].

    




              


    net=w[0]+w[1]*rs+w[2]*ls      

    net2=w[3]+w[4]*rs+w[5]*ls

  If weighted sum >=0 then its output 1 otherwise 0

    if net>=0: 

        s1=1

    else:

        s1=0

    if net2>=0:

        s2=1

    else:

        s2=0

What actual causes S1 to be either 1 or 0 is all defined by a set of weights w (three for the first neurone, S1,  three for S2).

w=[0,-1,1,-1,1,-1]

Converting the outputs of the two neurones S1 and S2 into actions is shown below.

    if s1==1 and s2==1:

        forward(40)   

    elif s1==0 and s2==1:

        forward(30)

        right_turn(10)

    elif s1==1 and s2==0:

        forward(30)

        left_turn(10)       

    elif s1==0 and s2==0:

        backward(40)

The functions for forward, right_turn, etc are defined elsewhere.

At the moment the movement is a bit rough and it is a little simpler to build a version that follows the centre of the line; this approach though, works with thinner lines. 

To change the function of the system, change the values in w; for example to produce one that follows the centre of the line just change w (I will leave that to someone to work on). The complete code is shown below.

Code

from microbit import *

import neopixel, random, array

w=[]  

def forward(n):

    pin0.write_analog(551)

    pin8.write_digital(0) 

    pin1.write_analog(551)

    pin12.write_digital(0)

    sleep(n)

    

def backward(n):

    pin0.write_analog(551)

    pin8.write_digital(1) 

    pin1.write_analog(551)

    pin12.write_digital(1)

    sleep(n)

    

def right_turn(n):

    pin0.write_analog(511)

    pin8.write_digital(0) 

    pin1.write_analog(511)

    pin12.write_digital(1)

    sleep(n)

    

def left_turn(n):

    pin0.write_analog(551)

    pin8.write_digital(1) 

    pin1.write_analog(551)

    pin12.write_digital(0)

    sleep(n)

       

w=[0,-1,1,-1,1,-1]

while True:

    ls= pin11.read_digital()

    rs= pin5.read_digital()

    

    net=w[0]+w[1]*rs+w[2]*ls

    net2=w[3]+w[4]*rs+w[5]*ls

    if net>=0:

        s1=1

    else:

        s1=0

    if net2>=0:

        s2=1

    else:

        s2=0

   

    if s1==1 and s2==1:

        forward(40)   

    elif s1==0 and s2==1:

        forward(30)

        right_turn(10)

    elif s1==1 and s2==0:

        forward(30)

        left_turn(10)       

    elif s1==0 and s2==0:

        backward(40)

       

           

    

All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with. Twitter @scottturneruon