As our project “Making Electronics Accessible to People with Learning Disabilities” satisfied the criteria for Design for All (http://designforall.org/) we can now use the logo in association with this part of the project:
Design for All
littleBits go LARGE
We used littleBits with our group from Reading College to introduce technology and ways of activating sounds, light and smells from the smell box (below). They worked well in many senses, but there were a number of issues with using them:
To address some of these issues, we designed a base with which to attach the littleBits components, increasing the size of the platform which might make the objects easier to handle. The initial prototype was made out of balsa wood to get an idea of the size, and to address issue 1 above we decided on a form which is tessellated, so that you cannot get the bit the wrong way round. Because the original components are clamped to the top of the bases, you cannot get them upside down either, which addresses issue 2:
Prototype made from balsa wood
The image below shows two input devices, two output devices and the power block:
Two input, two output and power
Close up of a bigger bit which extends the LED bit:
LED Bigger Bit
A simple circuit using the Bigger Bits:
A simple circuit using the bigger bits.
The next image shows a close up of the connectors that were used. One end of the base has three spring connectors (these are just spring pins, with wires soldered onto them), and the other has a connector is made from model engineering brass tube (1.1mm diam):
Spring pin connectors
The image below shows a close up of the static connectors made from brass tubing. The magnets are 4mm x 4mm diameter. On reflection 5mm x 5mm diameter would be better, and hold the blocks together more firmly.
Brass tube static connectors
A view of the underside of the base shows the (rather crude) connections. These actually worked well (to my surprise!). The only difficulty with connections were the brackets which connected to the littleBits themselves. As the bits have very small and fragile connectors, a few were damaged in the process of making this, and so the brackets are being redesigned to include very light spring connectors (similar to the ones used by littleBits).
Connections to spring pins and static connectors
The next stage of development will include the following:
If you have any comments or suggestions, then please contact me.
Here is the full size potato battery. It is made from a plank of oak, with a plate of zinc and a plate of copper screwed to it. The metal plates have dimensions 80mm x 1000mm, and were chosen so that they would fit on a 1m plank. It hasn’t yet been tested, but we might schedule this for the workshop on Thursday … 🙂
Full size Potato Battery
The next stage is to attach the wires that will connect the potato battery to the microcontroller. We’ll use simple screw terminals, and screw the wires to the plates.
We took the three smell boxes to MERL to test them with the group from Reading College. They had already used littleBits in two prior workshops, so were acquainted with them and had some idea of what they should do with the parts. A demo of how the smell box is used was given first and then they were handed out for testing. In the image below, a smellbox is being triggered with a push button (and an LED inline, too):
Two (further) deficiencies of the box:
It might be better if the smell emanated from the top of the box, and blown at an angle so that it is properly distributed. Below, a participant in the workshop examining the smell box (it contained a twig of rosemary):
The ‘smell box’ has finally arrived! It is based upon the same container as the prototype (so currently a bit large), and uses the same low power PC blower to move the air around. A 4N35 opto-isolator is used to separate the littleBits circuit from the circuit that powers the fan (which is controlled by a BC547), and the whole thing is powered by a 11.1V LIPO RC battery:
Similar to the Sound Box (see below) the Smell Box has littleBits circuitry integrated, and can be activated by any of the littleBits triggers:
The ‘smell’ itself is placed inside a small box embedded in the lid of the Smell Box. There are some ventilation holes drilled in the smell container (the off-white thing in the lid) and also a number of vents scattered around the box itself. It was tested with a piece of goat cheese:
To contain the smell of the cheese, the lid was pressed onto the smell container (which is almost air tight). However, the circulation was quite poor (despite the numerous ventilation holes), and so was tried again with the lid partially off:
This was better, and you could get a good sense of the cheese smell wafting from the box. But the design could be improved significantly in a number of ways:
We will trial this next week (18 Nov 2013) and see what happens with our target group. A report of how well it worked will be posted here soon.
In the meantime, we’ll be developing version 2 of the smell box, and include the improvements. Rather than hack boxes to pieces to make the new version, it would be a good idea to 3D print the next one. We’ll post the design on here when it is ready.
The Sound Box has had another update, and now includes an external speaker socket. this means that it can be plugged into an external amplifier/speaker or some other output device that can handle the analog signal. The image below shows the new jack socket with a device already connected via a jackplug:
Sound Box with new external plug socket
In the next image a surface transducer (a surface speaker) is plugged into the Sound Box. The transducer itself is attached to a 1.2mm zinc plate with a strip of BlueTack. The transducer makes the zinc plate vibrate to produce sound.
Transducer attached to a zinc plate with bluetack
The final image is a close-up of the transducer. You can buy these for around £5.00 each (or less) from many outlets on the web.
Transducer
The next experiment will be to connect the Sound Box to an external amplifier, and from this to a much more powerful speaker. The speaker will be attached to a metal plate and we will look at how the sound waves propagate on the surface of the plate to produce patterns (visible using fine sand or powder).
For one of the forthcoming workshop at MERL, we might explore how potatoes can produce energy using a setup similar to this, and demonstrate that you can do more with a potato than boil it, mash it or make chips (french fries, if you are not from UK). The images below show the simple battery setup using a zinc plate and a copper plate with a small gap between them.
Zinc and copper plates
A potato (or two in this case for a larger current) is placed across the plates:
Potatoes placed across the two plates
The current measured across the plates was about 160uA:
Measuring the current generated by the potato battery
The next stage of development will be to drive a set of LEDs to indicate the current generated.
The (temporary) sound boxes have been updated so that they can be triggered via littleBits circuits. Each box now has two littleBits connectors at one end – one for input, and one for output. They have been tested using a simple toggle button on the input side, with an LED connected to the output:
As the large playback-only soundboxes worked fine at MERL, and the small size of the last version made it very difficult to get all the components in, the sound recorder has been scaled up.
The old version, the new one, and a quick model of a pint glass I had nearby for scale.
The speaker on the last version was crudely glued to the bottom, and didn’t really fit properly; the new one has a proper piece to hold the speaker with a grill to protect it. The bayonet fitting idea was copied from the top piece of the old design.
The joint between the bottom piece and the main body is less obvious than the top/body joint as the edges aren’t rounded off, but it should still be secured with glue, tape, screws, etc to stop users from undoing it.
It was noted that it would be nice to be able to ‘point’ the device at the desired sound, like a microphone or dictaphone. The previous version had the microphone mounted in the side of the main body. The new one has a socket in the centre of its top, with a small grill to protect the microphone.
As the new case is so much larger, this should allow for more complex electronics (perhaps a microphone preamp to clean up recorded sounds a little), and larger batteries, as well as being easier to construct.
It will take considerably longer on the 3D printer though. It’s unlikely that more than one case could be printed simultaneously.
The pilot workshop at MERL was based upon two main activities, both relating to sound. The first activity involved looking for objects around the museum that could have produced specific sounds that we provided on custom-built sound players (which we informally refer to as the ‘Sound Boxes’):
The Sound Boxes
The sound boxes were designed to be as simple to use as possible: turn the dial to one of the six positions, press the big button and the sound will play. We have used sound recorders/players in previous workshops, but they are often very complicated to operate, and therefore require someone to assist in using them. For this pilot, members of the group were given the sound boxes and asked to try and locate the source of these sounds from around the museum. The activity itself worked very well and engaged the group members. The boxes themselves also performed very well too, and produced good clear sounds. More importantly, everyone could use them.
The sound boxes were also used in the second activity, along with various other sound making objects, to produce a soundtrack to a silent movie clip.
We are planning on extending the capabilities of the sound box to more sounds, and possibly create distinct players for different categories of sound. i.e. one for mechanical noises, one for animal sounds, etc.
