Another version of a pig in a bucket, produced by Rachael McGowan. In this design, instead of squeezing the ears or nose (like Rachel Hallisey’s pig) this one grunts and jumps about when you stand near it. The pig is made from papier mache and will sit on top of a platform near the top of a bucket. The platform moves up and down and takes the pig with it. Here is the original pig (which is used, not reproduced):
The pig that will be go into the jumping pig bucket
The original idea for making the pig move around was to use solenoids, but solenoids with a decent plunger reach (the amount of movement) are expensive and require a lot of current. So instead, we opted for a high speed servo. The mechanics are shown in the next few images. We first cut the bottom out of the bucket and fitted a wooden base, and glued this in place. Two holes were also cut at the sides of the bucket which supports the metal pivot. The pivot rests on 3D printed plastic supports (not shown here, but in the next image) that fit through the sides of the bucket, and act as bushes:
Base fitted to bottom of bucket, and pivot for moving platform
The servo fits onto the base:
Servo attached to base
The servo is then connected to a lever assembly which attaches to the moving platform, and rocks on the pivot:
Servo mechanism
The next image shown the platform in position:
Platform on top of pivot
The pig is not attached to the bucket but is free to jump about on top of the platform. We put grass on the platform and let the pig roam free! The video below shows the working model:
The ‘Hole in One’ bucket is Luke’s creation, and is the result of the workshops in which our group explored what they could do with buckets, boots and baskets around a rural theme. Luke plays golf regularly and so wanted this to be reflected in his creation. The original is below:
Luke’s original Hole in One design
To reproduce the design, we cut out the top from a sheet of plywood (rather than cardboard as Luke’s original design):
Cutting out the top
The top is just large enough to fit over the bucket with a small rim:
Top for ‘Hole in One’ bucket
We then used a hole saw to cut out the hole in the top, and also to cut out the hole for the tube from which the ball (or egg!) appears. The tube will be connected to a short down pipe which is hot glued to the top.
Bucket with hole cut for tube
The next image shows the down pipe (yet to be trimmed) glued to the wooden platform that fits at the top of the bucket and which the flexible tube will connect to:
Wooden platform with down pipe
This sits on top of the bucket and wedges between the handle posts:
The wooden platform on top of the bucket
Before adding the tube to the down pipe, we added an IR LED and sensor which will trigger the sound. The IR LED points directly at an IR phototransistor (they are matched and so have the same wavelength). When a ball is dropped down the pipe, the beam is broken, and this is converted into an instruction which triggers a sound:
IR sensor. The opposite side of the pipe has a matching IR LED
The sounds are grouped into two sets of three, and each set can be selected by inserting one of the two flagpoles into the top of the bucket. Each flagpole has an RFID embedded in it, and the top of the bucket has an RFID reader. Originally we anticipated a lot more sounds which we wanted to group into different sets, hence the use of the RFID and reader. However, we eventually honed down the number to just six. It’s a novelty, which would be used to extend the scope of sounds in the future. The image below shows how small the RFID pill is – it is placed next to a 6mm diameter wooden dowel:
The RFID before being inserted and glued into the wooden flagpole
This has been a long time in the making, and we have finally got to the stage where we can add the chicken to the mechanism and electronics. The design is a chicken (made from papiermache) sitting inside a hand basket, and Rumena wanted it to cluck and flap its wings like a chicken. That meant we had to find a way of attaching wings and then making them flap at the same time as generating the clucking sound. Here is Rumena’s original concept at the centre front. It is the yellow and red one between the bucket and the boot and the head is pointing towards the left:
The chicken-in-a-basket
The sound player is straightforward and is an Adafruit WaveShield attached to an Arduino Uno. Most of the objects we have creeated have this setup, as it is easy to work with and inexpensive. Also, I personally like the WaveShields as they have a simple design and so easy to understand. I have build around 40 of them.
The original mechanism for flapping the wings was based around a crank that was attached to two conrods, and which operated two levers attached to the basket. But this was too bulky and would not fit under the chicken. So, instead, we opted for a high speed servo. The servo pulls and pushes on levers attached to dowls which are themselves attached to the basket, but can rotate. It’s probably easier to just show the image below:
Mechanism for operating the wings
The wings are then attached to the dowels and can flap backwards and forwards, but only by around 60 degrees of rotation at most. the servo is controlled using a Polulo Micro Maestro, as this makes it easy to control via simple serial commands sent to it by the Arduino Uno:
Testing the servo controller
The whole flapping/clucking is triggered using a sonar attached to the Uno. Moving within 1m of the chicken will trigger it. In the image below the sonar is hooked up to the Arduino Uno, and the Arduino is connected to the servo controller (not shown). The sonar is a very inexpensive off-the-shelf HC-SR04, which has a range of about 3m.
Testing the sonar
The next image shows the whole setup with the servo and controller too. Note the simple mechanism to operate the levers on the basket.
Testing the servo and sonar
As with most of the other objects we have created, the audio uses a 3.5W kemo amplifier, and a 5W Visaton speaker The whole thing is shown in the image below:
Basket, complete with flapping mechanism and audio hardware
At the top centre of the previous image there is a voltage regulator. This is a replacement to the original, which was faulty and consequently I managed to fry two servos before sussing out that the voltage regulator was kaputt. In fact, one of them actually went up in smoke as I was on a Skype call with Kate!
Two ex-servos now leading an aimless existence
The Chicken was a bit floppy as it is made from papier mache, so Kate stuffed it to make it a bit more robust and so that the head would stay in place:
The Chicken was a bit floppy, so Kate stuffed it to make it a bit more robust.
The wings were attached to the two shafts that protruded from the top of the basket, and which are directly connected to the servo which makes them flap. We covered the mechanism with the lining form the basket, and attached the sonar (distance sensor) to the front of the basket so that the chicken would start flapping and clucking when someone stands in front of it:
Adding the wings to the basket
Finally, the chicken was fitted into the basket! The egg at the side of the basket contains the giant battery that powers it.
Chicken in a basket (a.k.a. Rumena’s funky chicken)
Here’s a video of the chicken when we tested it out:
Rachel’s original design of the “Pig in a Bucket” is shown in the photo below, bottom centre. She wanted her pig to make sounds when you squeezed its nose. We have also added sensors to the ears!
Group photo, showing Rachel’s “Pig in a Bucket” at the front.
This is still a work in progress, and although much of the hardware has been constructed, the sensors for the nose and ears have yet to be built. Here is what we have so far.
There’s a hole in my bucket ..
We started with a plain galvanised 15l steel bucket, and then cut the bottom out of the bucket with a jigsaw to provide access to the electronics (when they are fitted). The hole had quite a rough edge after using the jigsaw, so this was flattened down with a planishing hammer and dolly!
Galvanised steel bucket with the bottom cut out.
A small hole was also drilled in the side of the bucket for fitting the on/off/volume switch. The electronics are mounted on a wooden panel that fits into the bucket near the bottom, but leaving enough room for the electronics. The photo that follows shows some of the electronics mounted onto the board:
Amp and speaker mounted on base board – the Arduino was removed for this picture.
The board was glued into place in the bucket, so that it does not fall out:
Base board glued into place near the bottom of the bucket
Rear view of bucket showing the base board with the electronics mounted. You can see the on/off/volume switch at the side of the bucket. The sound is produced by an Adafruit WaveShield attached to an Arduino Uno. The sound is fed through a 3.5W mono Kemo amplifier and into a 5W Visaton full range speaker. There is a small amount of buzz which I haven’t managed to remove, but it is not noticeable when the sound is playing. The whole thing is powered by a 1000mAh Turnigy Li-Po RC battery, as they are light and powerful.
Bottom view – Electronics mounted onto base board and glued into the bucket
The bucket still needs to be decorated (as per Rachel’s design), the pig fitting and the sensors fitting to the pig. We’re hoping to complete this part by next week ready for the next workshop at MERL.
Below – we are attaching the new nose (containing an off the shelf pressure sensor) and the ears (which each contain a pressure sensor constructed form resistive plastic). The pressure sensor in the nose is situated between the cream coloured foam and the pink foam which forms the end of the nose (which Kate made independently, and managed to get the dimensions spot on!). It was intended as a ‘push’ sensor, so pushing on the end of the nose would trigger the sound, but it also appears to work well when squeezed, which is an added bonus.
Adding the new nose and ears to the pig
The ears were more difficult to construct. We wanted the whole area of the ear to work as a sensor, rather than an isolated area, which would be the case if we used a small off the shelf pressure sensor. So we used conductive (copper taffeta) fabric with resistive plastic (Velostat) sandwiched in between. The resistive plastic becomes more conductive the harder you squeeze it, so it works like a simple variable resistor.
Constructing the ears from resistive plastic and conductive fabric
One downside to the construction of the ears was that they have to be kept flat. Bending them would lose the resistivity. We did (obviously) try to create curved ears, but they were very inconsistent in operation and unreliable. Hence we stuck with flat ears and made sure they were attached to the pig flat! The wires were attached (using ordinary wire) to the ears by sewing them with conductive thread to the tabs at the bottom (see image below), and then gluing in place:
Squeeze sensor ears for the pig in a bucket
There was also a slight bug in the software when we initially tested it out, but it was easy to solve, and the finished item is below. It’s beautifully colourful!
In the image below, Sian is holding the boot that she developed at the workshop sessions that we held at MERL. She covered the boot with faux cow hide and wanted it to moo when touched.
Sian holding the wellington boot covered in faux cow hide that she designed. This is the original boot which was used as the basis for the mooing welly.
To produce the mooing sound, we used an Arduino UNO together with a wave shield, a 3.5W mono amp and a small speaker:
Arduino UNO with waveshield and amplifier
To trigger the sounds with the Arduino, two contact microphones, a tilt switch and a pressure sensor were used. The two contact microphones were stuck to cardboard bases (about 10cm square), and the bases were then glued to each side of the boot – these formed the strokable areas:
Contact mics before attaching to cardboard bases.
Initially, we tried to construct a simple squeeze sensor using resistive plastic (Velostat) and copper fabric. However, although it worked very well when constructed as a flat sensor, the curved version that was attached to the boot was very tempremental! Subsequently, we opted for a pressure switch which works very well:
Pressure switch using to trigger a sound when the toe area of the boot is squeezed.
The speaker was attached to a wooden base which fitted inside the opening of the boot and secured from slipping with a thin aluminium band screw into the boot. This was later covered with fur to match the boot. The image below shows the fur being attached with contact adhesive:
Faux cow hide being attached to the speaker base.
The Arduino sketch that triggers the sounds was written so that when the sides of the boot were stroked, the toe squeezed or the boot tilted forward, the sound would play. The sound will continue to play as long as the boot is stroked or the toe squeezed and will stop approximately 2 seconds afterwards. Email me if you would like me to send you the Arduino sketch.
Here are some images of the final boot – we will upload some video when it is tested out:
The mooing boot
Below is a picture of Claudia holding the boot after attaching the faux hide – she did the nice needlework!
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:
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:
Each of the littleBits components has a pair of magnets on each face to hold the bits together when assembling circuits. Most of the bits have two faces, but it is difficult to tell which is for input and which is for output. If it is the wrong way round, then the objects will not snap together.
It can be difficult to tell whether the component is the right way up, as the top and bottom are similar in appearance. If they are the wrong way up, then you cannot connect the bits together.
The affordances of the bits are often unclear, so it is not always obvious what to do with them. For example, the microswitch has a small roller attached to a metal arm, and which should be pushed inwards (i.e. towards the body of the bit) to operate. But this was often pulled outwards instead. The microphone trigger also caused some confusion until it was demonstrated. As it looks like a button, it was pressed rather than talking or clapping close to it.
Some additional cues would help people to understand whether the bits were connected correctly. For instance, the inclusion of a small indicator LED on the edge of each bit that illuminates when the two bits are properly connected might be helpful.
Controls on the littleBits objects are very small and difficult to operate if you have limited manual dexterity. Although the two group members in the images above (See Figure 2) managed to work the controls (including using the tiny screwdriver provided to adjust the sensitivity of one of the sensors), it is clear that they would benefit greatly from larger, more robust, controls.
Whilst not a criticism of the design, the bits are small which can be a problem for our co-researchers, many of whom have limited motor control or manual dexterity, and may cope better with objects which are larger.
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:
lightweight spring connectors built into the brackets, which should help to provide a better contact to the littleBits components
possibly led indicators on one side of the base which illuminates when the connection is properly made (I’m not entirely sure how much this would help, and needs to be trialled first)
slight redesign of base to use smaller spring pins (i.e. not quite so long) which will press fit into the base, together with off-the-shelf static pins, rather than brass tube
removal of some of the material from the base to make it a little lighter and also save on the cost of 3D printing
3D printed in different colours to reflect the purpose of the component (i.e. blue for power, green for output, etc)
modify the sound box and smell box (below) to use the new type of connectors
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:
The fan is underpowered, in the sense that it does not push enough air volume;
The fan seems to blow at an angle, and not directly out of the rear port. This means that you have to place your nose somewhere in line with the corner of the box to smell it.
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):
