Robots and Physical Computing

Thursday 15 April 2021

Eggbot 2- the drawing crumble junkbot.

figure 1

An earlier post https://robotsandphysicalcomputing.blogspot.com/2021/04/junkbots-2-eggbot2.html discussed the start of the development of a two motored Crumble (from Redfern Electronics) based 'junk-bot'; based around controlling vibrating motors (https://amzn.to/3mtxEy9) to move the bot.

This post focuses on addressing some of the issues raised in the earlier post. The motors are now glued, via a glue gun, onto the plastic egg (figure 2) and four felt-tip pens are also glued on (see figure 1 above) so there is a firm connection to the egg. Setting the pens in the right positions is the trickest part of the process and you are probably best to experiment with tape / sticky tack before finally gluing them in place.

figure 2

figure 3

I like the Crumble for this task because it is designed to control two motors using a simple graphical programming language, without any extra hardware.

figure 4

The program shown in figure 4 is trying out a lot of the possible combinations of direction for the motors. When the program is run it moves in (and draws squiggly lines) mostly, in arcs. There is still some work to be done on controlling it. It is sensitive to wires being touched, perhaps thinner wires connect the Crumble (figure 3) and the motors? The motors are perhaps not strong enough - though it does move, so perhaps stronger motors, upping the percentage power to the motors or upping the voltage (currently 4.5 to 6v and still within the capacities of the motors)?

It is good fun; there is a lot that can be experimented with, placement and direction of the motors just being one area.

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 9 April 2021

Junkbots 2 - eggbot2

A new iteration of the junkbots project or more accurately the Crumble-based eggbot sub-project (https://robotsandphysicalcomputing.blogspot.com/2017/10/crumble-based-junk-eggbot.html) is underway.

Previously it has been built around a single vibrating motor, 'controlled' in the loose sense by a Crumble Controller. (https://amzn.to/3dNl09e).The new development is to use smaller vibrating motors but two of them, controlled by the Crumble. This post looks at the early stage of the development and suggests where to go next.

Currently, two vibrating motors (https://amzn.to/3mtxEy9) have been attached horizontally to half a plastic egg (figure 1), the kind you can find in dispensing machine with plastic toys, but Kinder Egg ones can also be used. A Crumble is used to control the motors separately (figure 2) by changing the motor's direction. Health warning: It is never going to accurate control but that is part of the charm.

Figure 1

Figure 2

The Crumble code (https://redfernelectronics.co.uk/crumble-software/) used to test the system is shown below.

It moves and changing the direction of the motors does seem to have an effect.

What needs to be done?

There is a need for the motors more securely and the same with the wires to the motors. At the moment the motors falling off and wires disconnecting are the biggest problems.
Trying out the new model with pens to get it to draw is part of the next iteration.
Investigating the effect of directions and speed of the motors also needs to be investigated.

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 2 April 2021

Most read posts on the Robots and Physical computing Blog - March 2021

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 14 March 2021

Initial experiments with Code Bug Connect

Code Bug has been around for a while, and it is incredibly cute, When it first came, it was a very interesting piece of kit - and it is still is and fun to play with. It spec means it is still a very useful piece of kit.

5x5 Red LED display
2 buttons
6 touch sensitive I/O pads (4 input/output, power and ground)
Micro USB socket
CR2032 battery holder
Expansion port for I2C, SPI and UART

Blockly-based online programming interface
CodeBug emulator for checking code before downloading

In 2020 Code Bug launched and successfully funded a Kickstarter campaign (https://www.kickstarter.com/projects/codebug/codebug-connect-cute-colourful-and-programmable-iot-wearable ) for a new version the Code Bug - CodeBug Connect with a serious upgrade.(and the name Connect is highly appropriate with USB tethering and Wifi capability in this version. The technical specification (taken from their site https://www.kickstarter.com/projects/codebug/codebug-connect-cute-colourful-and-programmable-iot-wearable ) shows how much of an upgrade this is:

5x5 RGB LEDs with dedicated hardware driver/buffer
Two 5 way navigation joysticks
Onboard Accelerometer
4 GPIO legs, including high impedance sensing for detecting touch (think MaKey MaKey TM)
6 Sewable/croc-clip-able loops. 4 I/O including analogue 1 power and ground
6 pin GPIO 0.1" header (configurable for UART/I2C/SPI, I2S or analogue audio out)
QuadCore -- four heterogeneous processors
4MB Flash Storage
2.4GHz WiFi 802.11 b/n/g, Station and Soft AP (simultaneous)
Experimental long range wireless 0.8km to another CodeBug Connect
UART terminal access over USB
High efficiency SMPS Boost convertor for battery (JST PH connector)
High efficiency SMPS Buck convertor from 5V USB

Recently the early version of the Connects have been arriving and it is cool (IMHO).

The getting going guide https://cbc.docs.codebug.org.uk/gettingstarted/quickstart.html lives it up to its name and does a better explanation of doing this than I can provide here.

First I played with the USB and the blockly style programming tool https://www.codebug.org.uk/newide/ (see above) essentially producing a very slightly modified version of their starter code. You can perhaps see the Python style coming in with the while True coming in. Works well and it showed one of the different between this version and the older one; the LEDs are now colourful instead of red only. Programming it, while using the laptops USB to power it does lead to pulling the cable in and out to get the code to run - but that is fine and is clearly explained in the guide

You can connect it via wifi to a phone or a laptop so tried it with a phone. The getting started guide explains it well and the online editor allows you to program in micropython and example is shown below

import cbc

from color import Color

import time

while True:

cbc.display.scroll_text(str(" Bug 1"), fg=Color('#f0ff20'))

time.sleep(1)

They have even thought about security. I set my system to connect via wifi through my phone; but when I want to connect through my laptop I had to go through the adoption process to try it on my phone and a laptop - sounds scary but it is well explained in the getting going guide and is relatively simple to do.

Looking forward to exploring the device a lot more, the guide also includes a number of code examples to play with and explore. A feature I particularly liked was seeing the block code rendered as python when using the editor on the phone.

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 6 March 2021

Make yourself a virtual gallery

This short post builds on the previous posts (below), unless you have used A-Frame before please have a look at these:

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

WebVR playtime 2: video, 360 video and objects

Using Glitch (https://glitch.com/) as a web development and hosting tool. We are going to create the start of a virtual Gallery, essentially 4 rectangles that images can be posted on, a cylinder that also images can be wrapped around and the floor and the sky.

To do it following is posted into the index.hml

<html>

<head>

</head>

<body>

<a-scene>

<a-box position="-1 2 -1"

rotation="0 -30 0" color="white" depth="2"

height="4" width="0.5"

src="https://cdn.glitch.com/febf6408-3c33-4608-ac90-b087753e5792%2Fpanic.png?v=1573395380360"></a-box>

<a-box position="-4.5 2 -1"

rotation="0 -30 0" color="white" depth="2" height="4"

width="0.5"

src="https://cdn.glitch.com/e7ab4c95-5e85-4dc0-9bee-da6f7e87efcf%2Fdiginorth1.PNG?v=1615066351771"></a-box>

<a-box position="-1 2 -6"

rotation="0 -30 0" color="yellow" depth="2"

height="4" width="0.5"

src="https://cdn.glitch.com/425c1a98-7ba9-463d-817d-6b491a516246%2F97b3bf6d-ced1-4041-80d4-b6c9a98ba43d.jfif?v=1614341330757"></a-box>

<a-box position="-4.5 2 -6"

rotation="0 -30 0" color="white" depth="2"

height="4" width="0.5"

src="https://cdn.glitch.com/e7ab4c95-5e85-4dc0-9bee-da6f7e87efcf%2Fvex2.gif?v=1615066487037"></a-box>

<a-cylinder position="1 0.75 -3"

radius="0.5" height="1.5" color="#FFC65D" src="https://cdn.glitch.com/e7ab4c95-5e85-4dc0-9bee-da6f7e87efcf%2FPicture1.png?v=1615066388587"></a-cylinder>

<a-plane position="0 0 -4"

rotation="-90 0 0" width="20" height="20" color="#7BC8A4"></a-plane>

<a-sky color="white"></a-sky>

</a-scene>

</body>

</html>

Now to change the images all you need to do is change the URL in the src="". If you are doing this in Glitch it is easier often to copy the images into the asset folder and copy the URL produced.

Ideas to take this further

Rotate the cylinder so the image can be seen completely from a standing position.
Wrap an image on the floor, sky or on a new shape.

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 28 February 2021

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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