Robots and Physical Computing

Friday, 26 October 2018

Adafruit Circuit Playground reacting to music (updated with simulator)

This post looks at using the Adafruit Circuit Playground Express to react to music. I used Adafruit MakeCode (https://makecode.adafruit.com/) to experiment with it.

The code is simple and shown below and using the acceleration in the x, y and z axis to selected values for RGB on the neopixels - the circuit is placed on a speaker and the vibrations cause the changes in the pixel RGB value. The 10 pixels are lit up in sequence, but it is so quick it is hard to see a difference between the pixels.

The video below shows it action with music available from the YouTube audio library “Eternal Structures” by Asher Fulero.

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

Tuesday, 23 October 2018

WebVR 5 Playtime: Augmented Reality to display Videos

In previous posts (post 1, post 2) I have raved over the brilliant combination of Mozilla's AFrame and Jerome Etienne's fantastic AR code - guess what this post is no different in that respect.

Here is the problem I was interested in - having a set of markers that when viewed, a different video plays for each marker.

Glitch is a great editor for this (for example https://glitch.com/~ambitious-hub ) easy to use and it can stored assets (in this case a video). Add the assets by clicking on the asset folder and then use the add asset button, upload the file. You will need the URL for the asset this is what is included as a source in the HTML files; you get this by clicking on the asset and then copying the URL.

So some initial code using Aframe and aframe-ar.js is shown below. This is set-up to display a video when the HIRO marker is shown to the camera.
<!DOCTYPE html>
<script src="https://aframe.io/releases/0.6.0/aframe.min.js"></script>

<script src="https://jeromeetienne.github.io/AR.js/aframe/build/aframe-ar.js"></script>

<body>
<a-assets>
<video preload="auto" id="vid" autoplay loop="true" crossorigin webkit-playsinline playsinline controls src="https://cdn.glitch.com/b0bce38d-a212-4ce2-a89f-9c03bd45e85a%2Fdeep_learning_example_(SD_Small_-_WEB_MBL_(H264_900)).mp4?1540209123141"></video>
</a-assets>
<a-scene embedded arjs="sourceType: webcam; detectionMode: mono_and_matrix; matrixCodeType: 3x3;">

<a-marker preset="hiro">
<a-video src="#vid" width="1" height="1" position="0 0.5 0" rotation="-90 0 0"></a-video>
</a-marker>
</body>

There is a problem, in some browser including Chrome the video doesn't play it needs something to make it play. A great solution can be found at https://github.com/jeromeetienne/AR.js/issues/400 revolving around adding a button to play the video; a new HTML file aframe_video needs to be created as per the advice; a new call to the HTML file aframe_video.html (<script src="aframe_video.html"></script>) and some extra code available in the advice needs to be add to index.html. If you want to see the code I used, please go to https://glitch.com/edit/#!/ambitious-hub; please feel free to remix and reuse; I have built this on top of code developed by others, so I more than happy for others to use it.

Another great tool (developed again by Jerome Etienne) is the AR-Code Generator https://jeromeetienne.github.io/AR.js/three.js/examples/arcode.html which you put your URL for the index.html file of your AR example in and it generates a Hiro marker and a QR code for the site (an example is shown below). More details can be found at https://medium.com/arjs/ar-code-a-fast-path-to-augmented-reality-60e51be3cbdf

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, 13 October 2018

It listens to me - Anki's Vector Robot

The Anki Cozmo is great fun to play with (loads of games to get it to do) and nice to program through the codelab (https://robotsandphysicalcomputing.blogspot.com/2017/06/program-cozmo.html) and is just so cute you want to play with it. But now Anki has released Vector (https://developer.anki.com/blog/news/hey-vector/) with it's enhanced camera and built-in microphones, essentially better sensors; but the main feature (so far) has to the speech recognition.

All request start with "Hey Vector", pause until the lights go blue; followed by commands for example

- "my name is" which records your name and then learns your face.
- "play blackjack" to not surprisingly plays games of blackjack with you.

There are a load of commands, including to get the time, the temperature, etc. I am partial, to getting a fist bump from it. I have only just started exploring it (ok playing) there are loads of features I have yet to play with - just got to let it recharge it has had a busy time.

It is early days with the features developed for it so far, the SDK for Vector is expected to be released next year, so it doesn't have all the activities that the brilliant Cozmo has but I am sure it will and more. It might be me but there is more of a feel of a robopet/companion to it, with the addition of capacitive sensor on the back to 'pet' it.

So in summary great fun to play with, love the voice recognition, ability to ask it questions, lots to explore with it and based its hardware and what Anki have done with Cozmo, I expect there is going to be a wealth of new activities to add the current ones.

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

Tuesday, 4 September 2018

University of Northampton - teaching and researching Blockchain recognition

Taken from: University of Northampton recognised for being one of a handful of institutions teaching and researching Blockchain

The University of Northampton has been recognised as one of only a handful of Higher Education (HE) institutions worldwide which are teaching or carrying out Blockchain research.

Blockchain is a shared, replicated ledger that underpins technology such as cryptocurrency, but also sets out to provide the foundation for the next generation of transactional applications.

Blockchain analyst website Diar has included the University of Northampton in a list of just 28 HE providers that teach aspects of Blockchain and/or conduct research into it.

Northampton does both.

Postgraduate students on the MSc Computing course are taught elements of Blockchain, including a general introduction to the basic concepts, plus coding and programming techniques.

Meanwhile, various Northampton academics, led by Senior Lecturer in Education, Dr Cristina Devecchi, have collaborated on a Blockchain project to help Syrian refugee children which has been promoted by the United Nations.

Dr Scott Turner, who teaches Blockchain on the MSc Computing course, has also delivered a talk with colleague Ali Al-Sherbaz about the subject to the British Computing Society.

The University’s Vice Chancellor, Professor Nick Petford, said: “It is good to see the work of the University of Northampton recognised as contributing to the academic and practical development of Blockchain.

“The technology offers a new way of looking at old problems with great potential to innovate across a wide range of our research activities from education and humanitarian aid to supply chain management.”

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, 1 September 2018

Build a Disco cube:bit that reacts to music.

In a previous post Micro:bit and Cube:bit 'says' Hello I introduced the start of me playing with the 4tronix Cube:bit. One of the things I want to try is get the cube to react to music, based around the accelerometers in a micro:bit picking up vibrations. Luckily, in an earlier post, I had done something similar for the Proto-Pic Micro:pixel (see Dancing Pixels for more details).

Essentially the idea is the vibrations from the music shake the micro:bit enough to give measurable changes in three axis, and these values are used to change the pixel's colour - in fact five pixels at a time.

The code shown below is all that was needed:
from microbit import *
import neopixel, random

np = neopixel.NeoPixel(pin0, 125)

while True:
for pxl in range (2,125, 5):
rd=int(abs(accelerometer.get_x())/20)
gr=int(abs(accelerometer.get_y())/20)
bl=int(abs(accelerometer.get_z())/20)
np[pxl] = (rd, gr, 0)
np[pxl-1] = (rd, gr, 0)
np[pxl+1] = (0, gr, rd)
np[pxl-2] = (rd, 0, 0)
np[pxl+2] = (0, gr,0)

np.show()

Here it is in action:

The music used in the video is

Please feel free to improve on this.

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 and Cube:bit 'says' Hello

Since seeing pictures of the 4tronix Cube:bit I have intrigued by it and now I have one. So what is it? It is a 3D array of neopixel-style LEDs, or another way of describing it a programmable box of LEDs (or just good fun). The option I went for the 5x5x5 array (125 LEDs) controlling it with a micro:bit, and the base for mounting and powering the grid.

Instructions for putting it together can be found at https://4tronix.co.uk/blog/?p=1770. My main bit of advice is read the instructions carefully especially if you go for the 5x5 options, at the time of writing, you need to move a standoff around but it is all in the instructions. Admittedly I missed this step initially.

So to playtime, using a microbit I wanted to spell-out HELLO across the grid using the Micro:Bit JavaScript Blocks/MakeCode Editor. Basically, my solution revolved around creating two JavaScript functions to produce vertical and horizontal patterns on the grid (sounds good saying that - reminds me of Tron). What is very useful is 4tronix's have provided their own MakeCode package (the URL needed is in the instructions https://4tronix.co.uk/blog/?p=1770 ), this was great it made it even easier to get programming. The plan was put H is one first vertical plane, the E on the next and so on.

The code to my solution is available here https://makecode.microbit.org/_ePhFgu13i97D or can be seen or download from below.

The video below shows it in action.

It isn't the cheapest option for producing a grid of neopixel-style LEDs but it probably one of the easiest ways to do this. Quite quickly (if you read the instructions) you have a 3D array of LEDs to program. Last but not least, it is fun. Now I have to think (or rather stop thinking) about all the things I want to do with this.

Another review and related links:

Review https://www.electromaker.io/blog/article/building-a-cube-with-cubebit
Lorraine Underwood's Cubert https://hackspace.raspberrypi.org/features/cubert-when-an-led-grid-wont-cut-it-take-the-blinkenlights-to-another

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, 20 August 2018

Getting Crabby with EduBlock for Microbit

This is really pulling together two recent posts, one when I started playing with Edublocks for the microbit and one about playing with BinaryBots Crab .

The BinaryBots Totem Crab is available at https://www.binarybots.co.uk/crab.aspx

Here I going to use Edublocks (https://microbit.edublocks.org/) by @all_about_code to control the claw of the Crab to close when button A is pressed (and display a C on the LEDs) and open the claw when button B is pressed. For a discussion on the Crab and what the pins are, etc goto http://robotsandphysicalcomputing.blogspot.com/2018/08/crabby-but-fun.html for more details.

The timing of the opening and closing is controlled by how long the C or O takes to scroll across the LEDs. As an aside, but I found it interesting (it appeals to my geekiness), if you save the blocks, using the Save button; it stores it as an XML file, an example extract is shown below:

Now I want to explore a little the Python editor in Edublocks; to see if it can be used to expand the range of activities. The code as it stands now:

Using some code developed by CBiS Education/ BinaryBots I have added some code to read the Crab's temperature sensor and display "Warm" or "Cold" depending on this. The code uses the struct module to convert between strings of bytes (see https://pymotw.com/2/struct/) and native Python data types. to work with the I2C bus which the Crab sensors use (more details on the bus can be found https://microbit-micropython.readthedocs.io/en/latest/i2c.html ). The code below was then download as a hex file to the microbit as before.

The Crab's reads in the temperature and displays either message "Warm" or "Cold" - currently repeatedly "Warm". The open and closing of the claws still works.

So this was a double win, I had a chance to explore whether the Edublocks Python works as advertised and it does and an opportunity to play with the Crab a bit more; a definite win-win.

Acknowledgement: Thank you to Chris Burgess and the team at Binary Bots/CBiS Education for sending me a copy of the Python code for accessing the sensors on the Crab.

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