Robots and Physical Computing

Sunday 25 February 2018

WebVR playtime 1: Basics of setting up, images and rotating blocks.

This is going to be a short series of articles about some experiments with WebVR Web based Virtual Reality - in this case based on the wonderful A-Frame (https://aframe.io) . Ok, a bit of context, I have been working with some MSc students on this area and we have been exploring this area together - I love learning from and with my students.

Firstly, it is great fun and nowhere near as hard as I thought it was going to be when I first started.

1. The approach
My approach is to use A-Frame (https://aframe.io) inside Thimble (https://thimble.mozilla.org ). Thimble was selected for four reasons it is an online editor, simple to use, it is free and you see the preview immediately. Its main downside is the size of images and videos has to be relatively small and not too many of them.

2. How easy is it?
You can pretty much treat it as HTML, after you have added the script file shown in bold.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<script src="https://aframe.io/releases/0.7.0/aframe.min.js"></script>
</head>
<body>
<a-scene>

</a-scene>
</body>

</html>
The items to be add all go between <a-scene> and </a-scene> with a parent-child relationship; for example A block of text saying Hello in black and making the sky orange are all 'children' of <a-sceme>:
<a-text value="Hello" color="black" position="0 1.8 0.5" width="10"></a-text>
<a-sky color="orange" ></a-sky>
For example
<a-scene>
<a-text value="Hello" color="black" position="0 1.8 0.5" width="10"></a-text>
<a-sky color="orange" ></a-sky>
</a-scene>

The video below shows setting up and adding a box to the scene.

This next video takes this a little further by adding rotation to an object.

In this video mapping an image to an object and changing camera position is looked at.

In later posts some further ideas will be explored.

To read more go to https://aframe.io/docs/0.7.0/introduction/

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

Monday 25 December 2017

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

Saturday 23 December 2017

Radio controlled microbit Robot Unicorn

In a previous post a robot unicorn was built from a kit (Do it Kits https://doitkits.com/product/robot-unicorn/) and controlled to do a fixed sequence of actions. In this post a similar thing will be done, but this time the actions are not fixed within the robot itself, but in response to messages sent from another microbit via the radio module.

Sending

Sends out messages via the microbit's radio module, e.g. fwd for forward or tr for turn right; as well the name of the actions scrolls across the microbit.

On the Unicorn

Revieves messages via the microbits radio module, e.g. bwd for backward or tl for turn left; then carries out the action for 500ms. The time was selected to give the system enough time to finish the action before the next message is expected.

All 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

Friday 22 December 2017

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

Sunday 19 November 2017

Micro:bit Robot Arm

In this post, I am discussing using a recently bought CBIS BBC micro:bit RobotArm, but play with it using Python (or rather micropython).

Set Up
Not a lot to set up really. The base and the arm are separate and are attached with four screws (so you will need a screwdriver).

The most difficult bit is the wiring the arm to the circuit/breakout board on the base, but instructions are available through CBiS Resource portal http://portal.cbis.education/teacher/hardware. You will need a log-in for this. Also on that site, there is an example Microsoft Blocks code which includes some instructions on inserting the microbit as well - the micro:bit goes in buttons side facing upwards.

Code
Taking the values from the instruction sheet for setting it - the micro:bit key bit - the following pins were selected.
Base Pins 0 and 1
Shoulder Pins 8 and 12
Elbow Pins 2 and 13
Wrist Pins 14 and 15
Gripper Pins 16 and 11 - this is the only one I haven't got working yet.

So to test it out, a simple bit of code to drive each motor in both directions was produced and is shown below.

This is good fun to play with. The use of the micro:bit is a good idea because it's ease of use to plug-in and 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

Monday 30 October 2017

Crumble based Junk-Eggbot

Full details at http://bit.ly/2yZ3dZT

There was three inspirations for this project

· Eggbot - http://www.instructables.com/id/Plastic-Egg-Bot/?utm_content=buffer9b065&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

· Femi Owolade supported by Nic Hughes ran a session at Mozilla Festival 2016 using the Crumble’s to make a wheeled robot.

· The junkbot project https://junkbots.blogspot.co.uk/

Kit

· Kinder Egg (without the Chocolate and toy)

· Crumble

· 4x Crocodile clips and leads

· Battery pack and 3xAA

· Vibrating motor

· Tape (lots of)
. Sticky-tack of some form.

· Pens

· Paper

· Scissors

· Glue and Gluegun (optional)

Stage 1: Fix the vibrating motor into the Egg.

Stick (sticky-tack is a good temporary method) the vibrating motor into the Egg with the motor electrical connections sticking out the bottom larger half of the egg. Make sure the unbalanced load is free to move – this is bit that causes the vibrations needed to move the egg.

Stage 2: Sticking the pens on.

This is the trickiest bit. Tape the pens on the egg. One suggestion that someone who tried it out suggested, was to use little bits of sticky-tack to position the pens on the egg before tapping the pens onto the egg.

If you are using three pens, the third pen should be placed so that all three form a triangle with equal sides, that means the egg can stand-up on a piece of paper on the pen nibs, without anything supporting it.

If you are using four pens, the other two pens should be placed so that all four form a square with equal sides, that means the egg can stand-up on a piece of paper on the pen nibs, without anything supporting it.

Stage 3: Add the battery pack and go.

Using two wires connecting the battery, to the motors. Remove the nibs and set the bot off. It is hopefully vibrating and shaking and scribbling lines on the paper.

To see one in action go to: https://www.youtube.com/watch?v=NRlntdmdQRo

Stage 4: Crumble Controlling

Disconnect the battery connection (the connections on the motor can stay as they are) from the junkbot. Connect the USB cable to the Crumble. To the right of the USB connect there are two connections marked + and -. Connect one wire to the + connection and the other end to the red wire of the battery pack. Connect a one wire to the – connection and the other end to the black wire of the battery pack.

Stage 5: Connect the Egg!

On the Crumble, on the right-side there are two motor connections connect the Motor to these connections. Don’t worry about which of the motors wires is need you swap them around later.

Stage 6: Programming it – Making the bot moves.

The software can be found at https://redfernelectronics.co.uk/crumble-software/ it includes how to set it up on your own machine.

Start the Crumble software. Drag from the left the Program start, motor, and wait blocks. Now join the up start block at the top and the motor block next and the wait block last.

Your code should look like this.

Click on the stop within the motor block. It should change to forward. Now you are ready to make it move. Press the green arrow and with the battery pack on, it should (hopefully) keep moving.

If you put a second motor block after the wait block with the stop in the block. It such then stop after 1 second of moving.

Stage 7: Making it do more.

- Drag a do-until block in (found in the control menu).

- Go to variable menu and add a new variable, I have used t, select the block marked let=, and drag a t into the blank space.

- Drag an increase block onto the screen and drag a t into the blank space.

Go to the operator menu and drag onto the screen an = block, go back to variables menu and drag a t into the first space on the = block and click on the second space on the block and type in 5.

Now for the challenge put all these together to copy what is shown below. Now, but the egg-bot on the paper, with the pen lids off, press the green triangle and the motors should be spun in different directions.

This is a junkbot so it may just cause the bot to move a slightly different directions but hopefully it should just draw some squiggly lines.

Attribution-ShareAlike

CC BY-SA

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

Monday 9 October 2017

Sphero Mini - fun-sized Sphero

The Sphero Mini has been recently launched and at the time of writing seems to be popular, Amazon.co.uk delivery times vary depending on the colour you select. There are some very good reasons for it to be popular.

It's a ping-pong sized ball, much smaller than the normal Sphero's and approximately half the price. Though slightly less featured, what it has got, is good.

In the box, you get the sphero-mini, a charging cable, as well as packet of mini-skittles and cones. There is no charging station for this one, you charge it taking the outer shell off (it splits into two pieces) and the socket is on the ball inside. Actually, it is quite interesting to see the insides (I know the Spheros SPRK+ have a transparent shell to show the innards) and handle the ball inside, trying to see what it does. The ball is a little slower than the other Spheros, but this is not a problem in my opinion.

There is an app for playing the games, and this is fun to play with; providing control via the app to make the ball move and many features I have yet to explore. Alternatively, the SpheroEdu app, running on a tablet, allows programming via blocks or JavaScript. Had to have a go with writing a JavaScript routine.

The routine just makes the robot go in a square and not really much of a test, but a start. I especially liked the visual display of the sphero-mini's route on the tablet's screen.

I think this little robot, the price is not bad, though less featured than their bigger 'sibling' Spheros it is still good. I would like to see support for Swift in the future but it is early days for this kit and the skittles and cones are a good touch.

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