Robots, fruit and computer coding

Taken from: https://www.northampton.ac.uk/news/robots-fruit-and-computer-coding-sixth-formers-get-a-taste-of-university-research/ by University of Northampton Press Team

A select group of sixth-form pupils has spent the summer working on a series of research projects at the University of Northampton.

Four pupils from Northampton and Kettering schools undertook projects involving robotics, coding and urban orchards after each were awarded a Nuffield Research Placement – a scheme which offers sixth formers the chance to work on university research projects.

David Obreja, from Northampton School for Boys, spent his time at the University researching the amount of fruit-bearing plants and trees in areas of Northampton, and mapping them on a computer.

He said: “We need more fruit-bearing plants and trees in the town to provide food for wildlife, encourage biodiversity and improve the aesthetics of urban areas. I hope my research might encourage residents to plant more species, which would also have a social benefit as people may take it up as a hobby. Growing their own produce will also increase their food security.

“The research might also inspire housing developers to consider the mix of planting on their new developments, by including more fruit-bearing plants, rather than planting that is purely architectural.”

Fellow Northampton School for Boys pupil, Nathaniel Roberts, spent his time at the University making a junkbot – a robot made from waste items, such as a drinks can, powered by a kit.

He then coded the junkbot to make it move and used his experiences to produce an instruction manual for junkbot beginners.

Nathaniel said: “The project has taught me how to manage myself, set aims and work towards completing them, and given me an insight into how to write a technical manual in language that’s informative and easy to understand.”

Michael Welsh, from Kettering Buccleuch Academy, spent the summer programming a robot to learn how to follow a straight line, using sensors.

He said: “It works as a concept, but pretty difficult to get it right in practice, and has meant lots of methodical research. I’d like a career in computer science and this project has been pretty intense and demonstrated things can be a lot more work than you initially assume, but I like a challenge.”

Hiren Mistry, from Caroline Chisholm School in Northampton, learnt how to program a robot before creating a set of tasks for Year 7 pupils to do the same.

He said: “It’s been fairly tricky, with a lot of research and testing, and has given me a real insight into computer science.”

The University’s Associate Professor in Computing and Immersive Technologies, Dr Scott Turner, said: “The Nuffield placements have been incredibly successful. The students were all set very challenging university level projects and have enjoyed a real taste of the work we do here.

“I was very impressed with their commitment and aptitude for their subjects and am sure they will all go on to be a success at university, should they choose to go down that route.”


Related Links to their work.

• Robot control by a neuron
• Crumbly Toilet Roll Junkbot
• Minecraft to move USB Raspberry Pi Robot Arm
• How to use PS3 controller to move USB robot arm

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 control by a neuron.

This year the Computing team has been fortunate enough to host three Nuffield Research Placement students (https://www.nuffieldresearchplacements.org/) all working with Dr Scott Turner.

Michael Welsh

Michael has been working on using a micro:bit based bitbot from 4tronix to produce a potential teaching tool; an example of artificial neurons used control a robot. The aim is for this tool to be used with 3rd-year Undergraduates, as part of a module on Artificial Intelligence.

Michael's solution was to use the computer to run and train a single neuron; then for the robot to send values from the line sensors back to the program running on a Computer and receive control signals. 

Sounds easy? No really, in the end, the software running on the computer had to also send and receive the data through a microbit (via USB) and then use radio to communicate with the bit:bot robot. All the various developed parts of the solution were implemented in Python by Michael.

Example of the code.

import serial
from math import fabs
import random
import sys
import glob


#TO DO: GUI, implement manual mode. Make manual mode a button?? When in automatic, weight boxes are greyed out. Otherwise, they are able to be typed into.

def forward(n):
    microbit.write(('f'+str(n)).encode('utf-8'))
def backward(n):
    microbit.write(('b'+str(n)).encode('utf-8'))
def turnR(n):
    microbit.write(('r'+str(n)).encode('utf-8'))
def turnL(n):
    microbit.write(('l'+str(n)).encode('utf-8'))
def end():
    microbit.write('e'.encode('utf-8'))


def serial_ports():
    """ Lists serial port names

        :raises EnvironmentError:
            On unsupported or unknown platforms
        :returns:
            A list of the serial ports available on the system
    """
    if sys.platform.startswith('win'):
        ports = ['COM%s' % (i + 1) for i in range(256)]
    elif sys.platform.startswith('linux') or sys.platform.startswith('cygwin'):
        # this excludes your current terminal "/dev/tty"
        ports = glob.glob('/dev/tty[A-Za-z]*')
    elif sys.platform.startswith('darwin'):
        ports = glob.glob('/dev/cu.*')
    else:
        raise EnvironmentError('Unsupported platform')

    result = []
    for port in ports:
        try:
            s = serial.Serial(port)
            s.close()
            if '/dev/cu' in port:
                if '/dev/cu.usbmodem' in port:
                    result.append(port)
            else:
                result.append(port)
        except (OSError, serial.SerialException):
            pass
    return result


class neuron:

    def __init__(self,ins):

        self.inputs = [1]

        self.weights = []

        for i in range(ins+1):
            self.weights.append(random.uniform(-1,1))
        #print(self.weights)

        self.LC = 0.005
        
    def get_output(self,inputs):
        self.inputs = [1]+inputs

        WSum = 0

        for i in range(len(self.inputs)):
            WSum += int(self.inputs[i]) * self.weights[i]

        sums = sorted([fabs(WSum), fabs(WSum - (1/3)), fabs(WSum-(2/3)), fabs(WSum-1)])
        #print(sums)
        if sums[0] == fabs(WSum): #return 0 - move backwards
            backward(5)
            return 'B',WSum
        elif sums[0] == fabs(WSum - (1/3)):
            turnR(5)
            return 'R', WSum
        elif sums[0] == fabs(WSum - (2/3)):
            turnL(5)
            return 'L', WSum
        else:
            forward(20)
            return 'F', WSum

    def train(self,inputs,desired):

        result = self.get_output(inputs)[1]
        print(result)
        error = desired - result
        #print(error)

        for w in range(len(self.weights)):

            change = self.LC * int(self.inputs[w]) * error

            print('change in weight ' + str(w) + ': ' + str(change))

            self.weights[w] += change


for i in serial_ports():
    try:
        microbit = serial.Serial(port=i, baudrate=115200)
        break
    except:
        pass

microbit.setDTR(1)
microbit.close()
microbit.open()

control = neuron(2)

mode = input('Automatic or Manual? (A/M)\n')
while mode.lower() not in ['a','m']:
    mode = input('Automatic or Manual? (A/M)\n')
if mode == 'm':
    control.weights[0],control.weights[1],control.weights[2] = int(input('Enter weight 0/bias: ')),int(input('Enter weight 1: ')), int(input('Enter weight 2: '))
while True:
    #microbit.write(input('input: ').encode('utf-8'))
    out = microbit.read(6)
    microbit.flush()
    try:
        out = out.decode()
    except:
        pass
    for i in range(len(out)):
        if str(out[i]) in ['0','1']:
            if i == 0:
                if out[1] == ']':
                    num2 = out[i]
                elif out[1] == ',':
                    num1 = out[i]
            elif i == 5:
                if out[4] == '[':
                    num1 = out[i]
                elif out[4] == ' ':
                    num2 = out[i]
            else:
                if out[i-1] == '[':
                    num1 = out[i]
                elif out[i-1] == ' ':
                    num2 = out[i]
                elif out[i+1] == ']':
                    num2 = out[i]
                elif out[i+1] == ',':
                    num1 = out[i]
        
        #print(out)
    try:
        sleft=int(num1)
        sright=int(num2)
        print([sleft, sright])
        if mode == 'a':
            if [sleft, sright] == [0, 0]:
                control.train([sleft,sright],0)
            elif [sleft, sright] == [0, 1]:
                control.train([sleft,sright], 1/3)
            elif [sleft,sright] == [1, 0]:
                control.train([sleft,sright], 2/3)
            else:
                control.train([sleft,sright], 1)
        else:
            if [sleft, sright] == [0, 0]:
                control.get_output([sleft,sright])
            elif [sleft, sright] == [0, 1]:
                control.get_output([sleft,sright])
            elif [sleft,sright] == [1, 0]:
                control.get_output([sleft,sright])
            else:
                control.get_output([sleft,sright])
    except:
        pass

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

Crumbly Toilet Roll Junkbot

Guest Blogger Nathaniel Roberts, Nuffield Research Placement Student working at the University of Northampton. Nuffield Research Placement scheme provides students in their first year of a post16 course to work with STEM professionals http://www.nuffieldfoundation.org/nuffield-research-placements.

Toilet Roll Junkbot

Nathaniel Roberts

Cut a slit in a toilet roll.

Cut another toilet roll in half, then arrange the pieces in a T.

Feed the bottom of the T into the slit, and tape together.

Cut two lines into the edge, and do the same on the opposite side of the circle. Copy this for the other side of the tube.

These geared motors from the Camjam EduKit 3 should fit into those gaps.

Stick a battery pack to the back, and use crocodile clips to wire it all up to a crumble. The battery pack can connect to the + and - on either side at the top of the crumble, and the motors connect to the + and - of their respective sides of the crumble.

Using a Micro USB to USB cable, the crumble can be plugged into a computer and can run code from the crumble software ( http://redfernelectronics.co.uk/crumble-software/ ).

This example code would make the junkbot move forward for a second, turn either left or right, then move forward for another second before stopping.

The back of the bot was extremely heavy (with all the batteries). The front wasn’t heavy enough to grip most surfaces very well so the wheels would often spin without the bot moving. Also, the toilet rolls were only just strong enough for the job. After a few uses, especially around the motors, they started bending. Eventually, the motors ended up 'wonky' despite attempts at fixing it.

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

Minecraft controlled Raspberry Pi Robot Arm

Guest Blogger Hiren Mistry, Nuffield Research Placement Student working at the University of Northampton. Nuffield Research Placement scheme provides students in their first year of a post16 course to work with STEM professionals http://www.nuffieldfoundation.org/nuffield-research-placements.

How to use Minecraft to move a USB Robot Arm on a Raspberry Pi

By Hiren Mistry

Currently, I am taking part in a Nuffield Foundation Research Placement at the University of Northampton, researching how to control a CBIS Robot Arm using a Raspberry Pi. This part of the project aims to learn more about using Python in Minecraft and how I can control the Robot Arm using Minecraft. When the player hits a specific block, the Robot Arm will move in a specific way.

Minecraft is an adventure game where players are put in a randomly-generated world and can create their own structures and contraptions out of textured cubes.

Here are the main commands used in Python for Minecraft Pi:

Command	Explanation
from mcpi.minecraft import Minecraft	Import modules from Minecraft folder
import minecraft.block as block	Imports Block Module
minecraft.Minecraft.create()	Used for creating a connection, modifying players and blocks and capturing events with the Minecraft World. This command uses the default address and port.
mc.player.getPos()	Return current position of player (as a float)
mc.postToChat()	Post message in brackets to Minecraft Chat
mc.setBlock(x,y,z,id)	Sets block (id) at position x, y, z
.setPos(x,y,z)	Moves player to position x, y, z
blockEvents = mc.events.pollBlockHits() for blockEvent in blockEvents:	This returns any block event hits since the last time the command was run.
BlockEvent.pos	Returns the position of the block that was hit

Before developing the main program which controls the Robot Arm, I wrote some basic programs which enabled me to learn more about how Python interacts with Minecraft Pi. One of the programs I created leaves a trails of blocks behind the player. Below is the code with explanations for each line. It works by using a While loop and continually checks to know if the player has moved. If the player has moved then a block will be placed. The block number (38) can be changed. 

For a list of block numbers and more information, go to http://www.stuffaboutcode.com/p/minecraft-api-reference.html

import mcpi.minecraft as minecraft #imports minecraft modules

import mcpi.block as blocksw #imports block modules

import time #imports time module needed for time.sleep()

mc = minecraft.Minecraft.create()#creates connection to mc game

while True:#Starts while loop

    pos = mc.player.getTilePos()#Gets position of player

    time.sleep(0.1)#Sleeps for 0.1 seconds

    newpos = mc.player.getTilePos()#Gets new position of player

    if newpos != pos: #if the position has changed

        mc.setBlock(pos,38)#Set Block 38 down on previous block

Robot Arm Program in Minecraft

Whilst researching into Minecraft Pi I had the concept that the user would press a button in Minecraft and a Minecraft ‘Sign Post’ would allow the user to know what that Minecraft button does. However, due to Minecraft Pi limitations Buttons and Signposts (with text) do not exist so therefore they cannot be used. As a solution, I produced a model of the Robot Arm in Minecraft (See Picture below), which would enable the user to move specific parts of the Robot Arm.

The torches are the blocks which will activate the Robot Arm movements (Except for the Grip Open/Close and the Rotate Clockwise/Anticlockwise blocks).

Limitations: As only one block can be hit at once, only one command can be out put to the Robot Arm. Therefore, multiple commands are not available.

Dictionaries

An easier way of storing data, such as the co-ordinates of each block, was to use a dictionary. A dictionary contains keys which are assigned to values. For example, Dictionary = {"Key1":Value1, "Key2":Value2}would store two keys where "Key1" is assigned to Value1 and "Key2" is assigned to Value2.

A more efficient way of storing the commands and co-ordinates would be to store the commands in another dictionary with the same key name. E.g.

Coordinates = {"Shoulder Up":[77, 67, 1], "Shoulder Down":[74,67,1]}

Commands = {"Shoulder Up":ShoulderUp(), "Shoulder Down":ShoulderDown()}

I could then search through all the keys and if the coordinates of the block hit equalled the value of a key, then the corresponding command would be executed. Using code such as,

For k, v in Coordinates:

If BlockHit == v:

Commands[k]

However, this code causes the an error (ValueError: too many values to unpack) as the Python code has to go through all the keys and values until a match is made. Therefore, I have decided to continue with the simpler code which uses many IF statements to decide which command to use.

Final Program

Below is the code which allows the player to hit blocks which control the Robot Arm.

Once Minecraft is running, press "TAB" and run the Python code and then switch back to the Minecraft Window.

Note: When hitting blocks in Minecraft, the sword has to be used to activate commands.

import mcpi.minecraft as minecraft #Imports Minecraft Module

import mcpi.block as blocksw #Imports Block Module

import time

from Maincommands import * #Imports Commands from Maincommands.py file

mc = minecraft.Minecraft.create() # Creates connection to Minecraft

mc.postToChat("Robot Arm Control")#Post message to Minecraft chat

pos = mc.player.getTilePos()#Gets position of player

print(pos)

while True:

    blockHits = mc.events.pollBlockHits()#Get the block hit events

    if blockHits:# if a block has been hit

       for blockHit in blockHits:   # for each block that has been hit

            print("")

            xyz = [blockHit.pos.x,blockHit.pos.y,blockHit.pos.z]

            print(xyz)

            Dict = {"Grip Open":[74,12,-70],"Grip Close":[72,12,-70], "Rotate AntiClockwise":[77,12,-63], "Rotate Clockwise":[77,12,-67],"Shoulder Up":[77, 13, -64], "Shoulder Down":[77, 13, -66], "Elbow Up":[77, 16, -64], "Elbow Down":[77, 16, -66], "Wrist Up":[77, 18, -64], "Wrist Down":[77, 18, -66], "Light On":[75, 19, -65], "Light Off":[76, 19, -65]}# Dictionary with Command and coordinates of block

            # Outputs command depending on block hit

            if xyz == Dict["Grip Open"]:

                OpenGripper(0.5)

            elif xyz == Dict["Grip Close"]:

                CloseGripper(0.5)

            elif xyz == Dict["Rotate Clockwise"]:

                RotateBaseClockwise(0.5)

            elif xyz == Dict["Rotate AntiClockwise"]:

                RotateBaseAntiClockwise(0.5)

            elif xyz == Dict["Shoulder Up"]:

                ShoulderUp(0.5)

            elif xyz == Dict["Shoulder Down"]:

                ShoulderDown(0.5)

            elif xyz == Dict["Elbow Up"]:

                ElbowUp(0.5)

            elif xyz == Dict["Elbow Down"]:

                ElbowDown(0.5)

            elif xyz == Dict["Wrist Up"]:

                WristUp(0.5)

            elif xyz == Dict["Wrist Down"]:

                WristDown(0.5)

            elif xyz == Dict["Light On"]:

                GripLight(1,1)

            elif xyz == Dict["Light Off"]:

                GripLight(0,1)

Related post
http://robotsandphysicalcomputing.blogspot.co.uk/2017/08/how-to-use-ps3-controller-to-move-usb.html

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