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Improving Lives – Digital White Cane

It can be hard to imagine what life would be like if you were blind. The simplest of tasks become much more difficult, and yet those who are blind can lead very full and active lives. However, one of the larger challenges they face, is navigating the hazard-ridden hustle and bustle of outdoors.

The use of a cane to aid those with visual impairments has been around for centuries , but it wasn’t until the early 20th century that the more familiar white version came into existence.

The purpose of the White Cane is to enable the user to identify obstacles on the ground, and alert other pedestrians etc., to the fact that they have a visual impairment. The basic design has stood the test of time, but what if we could improve this design by bringing it into the modern era? By adding an Ultrasonic Distance Sensor and a motor with an off-centre mass, we can create a walking aid that picks up on objects before we get close to them and vibrates depending on how close we are to them!

To make our digital version of the White Cane, we are going to combine the Crumble (for our programmable electronics), along with some other design elements, including some 3D printed parts.

As this is more of a proof-of-concept, we are not aiming for a retail-ready design. This is much more of a prototype, enabling us to try out ideas; an important part of any Design and Technology work! We have put together a list of the key features we needed to think about:

We decided on 3D printing a mount for the Ultrasonic, which would also accommodate a ping pong ball to help the cane move freely over surfaces.

The Ultrasonic slots into the mount upside down to allow easy access to the connections, and the cylindrical adapter allows a snug fit with the main body of the cane (PVC pipe).

At the other end of the cane, we wanted an ergonomic handle, so we designed and printed a core, around which we could use polymorph to create a custom grip.

To make the grip, we heated our polymorph using a heat gun (take care – it can get hot!) and then wrapped it around the handle piece and squeezed to get a custom moulding of our grip. Make sure your polymorph isn’t too hot – it will soften the PLA!

Then it was just a case of putting all of the pieces together. We used elastic bands to secure our motor mount and other Crumble components.

Finally, we just needed to program the Crumble to vibrate according to our own requirements. As a start, we got the cane to vibrate when we detected an object that is less than 50cm away.

And there we have it, our Electronic White Cane prototype! You could progress on from here in multiple ways, including, but not limited to: extending the program to make it vibrate at different rates depending on the distance away of an object; building a full-size version and testing it out by using blindfolds etc.; building a self-contained ‘finished’ version.

If you have a go at this project, or any other, we’d love to see! Get in contact with us via email, or on Facebook, Twitter or Instagram.

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Using the Low-Cost FM Radio Module

Great news! We’re having a bit of a clear-out in the warehouse and as such, we have lots of fantastic deals. One of the items on offer is our Low-Cost FM Radio Module. Originally based on a commercial PCB, this module is a complete working FM Radio. It scans at the push of a button, and locks onto stations automatically.

It is a great starting point for design-based lessons, and given that there is now nearly 40% off of the RRP, it is great value for money too.

Our Low-Cost FM Radio Module

We thought that we’d have a quick go at making out own housing for the radio module. We set our sights on a simple cubic design, with a base containing the ‘Scan’ and ‘Reset’ buttons. We designed a 2D template for the main cardboard body, and then we 3D printed our other parts to make a base with buttons, a volume dial and a speaker mount.

The inside of our FM Radio

We mounted all of the internal parts to the main body, mostly using nuts and bolts. After this, we glued the body together.

Once the body had dried, we put it onto out mount. To get the effect on the switches, we used some correction fluid, which we then sanded back once it had dried. This gave us an interesting effect; almost shabby-chic.

Our finished FM Radio

Once it’s all built, it’s just a case of switching it on and tuning into your favourite stations.

If you have a go at any design work using our radio module, or any other project, we’d love to see! Get in contact with us via email, or on Facebook, Twitter or Instagram.

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Make a 7-Segment Display with the Crumble

Here is our latest Crumble project, hot off the press!

Once again it all started with an idea. We wanted a better way of displaying numbers (and some letters) with the Crumble – and that got us thinking. In essence a 7-segment display is made of seven bars, which get lit up. So we decided to give it a go.

We started out with all of our resources. Along with this we used a glue gun and a pen.

After cutting out our templates, we stuck down borders around each segment and the whole display.

This is the basic ‘shell’ of the 7-segment display. It just needs Sparkles, and a paper covering to diffuse the light.

We then wired up the display, Starting with 0 at the top and working in an anti-clockwise spiral shape, connected them all together, gluing a card support to hold the Sparkles in place.

After wiring it up, connecting to the Crumble and programming it, we have our very own 9 second timer – using real numbers!

If you would like more information about this project and others, most of which include  free lesson plans, PowerPoints and worksheets, head on over to Redfern Electronics, our partner site and home of the Crumble.

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Getting musical with the Crumble

A Crumble powered instrument that can play a tune? You must be mad!

Don’t worry, we thought we were too, but after having this idea in our head for a long time, we finally bought a glockenspiel to try it out-  and lo and behold our Crumble powered glockenspiel is alive.

Surprisingly, you don’t need many parts to make the instrument work. A glockenspiel with a beater, two servos, some cable ties and a sticky pad or two. We placed it on a spare piece of corriflute so that we could keep the servos and the glockenspiel aligned.

We needed two servos for this. One servo with the “cross” attachment, and the other with the “double arm”. These were then wired into the Crumble, one on A and the other on B.

The two servos were then connected with sticky pads and cable ties. The bottom servo moves along the X axis (left to right), and the top servo along the Y axis (up and down).

To allow us to easily play the given notes, we created a variable for each one and worked out, through trial and error, which notes were at which angle.

We then moved onto setting out variables for a crotchet, a minim, and then the angles at which the top servo needs to be to hit the glockenspiel, and where it should rest at.

This is the block of code to hit the ‘F’ key, for one crotchet (same as the beat). The total of the wait statements is 750 milliseconds, which equals 80 beats per minute.

And there you have it, one Crumble-powered Glockenspiel! Our instrument came with some free music, so we decided to use one of those pieces. After piecing together many snippets of code, here is Beethoven’s 9th Symphony – well the first line, in all of its Crumble-y glory.

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Datalogging: The cooling effect of evaporation

This investigation looks at how evaporation can cause cooling. We have used two cups, two dataloggers, some paper towels and some water to measure the effect. We set up one cup with a wet towel on the top, and as a control, we had one with a dry towel.

We don’t need much for this investigation. We used two polystyrene cups, two pieces of paper towel, two  temperature dataloggers and some tepid water.

Within the ‘Mini-datalogger’ software it is possible to configure the datalogger to record temperature samples at varying intervals. We decided to set the dataloggers to record every two seconds, using the ‘single mode’, so we didn’t accidentally lose our data. We also chose to start logging a few minutes into the future, to make sure that we didn’t affect our data too much.

We placed one datalogger into each cup, with the circuitry near the middle. This should allow the air to circulate around the datalogger, giving us the most accurate reading.

Then we wet one of the paper towel squares with tepid water. We had to allow as much water to drip off as we could, so that we didn’t risk getting our dataloggers wet.

We then left them in the cupboard for a few hours, to allow the water to evaporate.

After around three hours, the paper towel was still very wet, so we decided to increase the airflow over the paper towel, by using a fan. This should cause more water to evaporate.

I repeatedly checked on the cups over the final 1hr 30mins as the paper towel on the dry cup kept flying off.

When I returned for the final time, the paper towel on the wet cup had blown off. This definitely proved that the water had evaporated, and the towel was almost dry.

Our initial results looked promising. The cupboard where they were being kept wasn’t heated so the temperature dropped considerably, and after 45mins – 1hr they levelled out. Interestingly, the cup with the wet towel was already lower in temperature than the dry one, and this continued to be the case throughout the investigation.

At around 13:40, the temperature of both cups increased – this was after the fan had been switched on. Due to the nature of the room, and the lights, we believe that the fan had caused the air to circulate, and even out the temperature. We are going to investigate this hypothesis. EDIT: See results.

As we mentioned previously, the wet paper towel had blown off, and it looks like this happened around 5 minutes before the end of the investigation, as there was a sudden rise in temperature recorded on the wet towel datalogger.

So far, it appears that the wet towel does help to cool the contents of the cup down, by evaporation. To see whether we can recreate and improve on our results, we will repeat the investigation.

This time we left the resources for the investigation in the room, for 45 minutes before the dataloggers started recording. This allowed everything to get closer to room temperature. After the first 15 minutes of datalogging, we then placed the wet and dry towels over the dataloggers.

The results this time did match our expectations. There was an initial rise of both temperatures, likely caused by the opening of the door. The wet towel cup continued to rise in temperature, after the dry cup had stopped. This is likely to be caused by the water used being slightly above room temperature – even after sitting out for 45minutes.

The wet towel cup then dropped in temperature, where it stayed about 0.6 degrees celsius below the dry towel cup temperature. The temperatures gradually rose in both cups until around 13:00 – this was when we checked the cups and obviously forgot to close the door! Interestingly, the dry towel cup temperature rose by more than the wet towel cup. The wet towel cup was then consistently around 0.8 degrees celsius below the dry one.

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Ideas for the Sound Recorder Module

Aim of project: To design and create a voice-recording product

Project Outline:

  • Research existing ‘talking tile’ style products;
  • Design a product which embeds the voice recording module;
  • Make the product;
  • Evaluate the product against design criteria.

Resources Needed:

  • Sound Recording Module;
  • Materials to produce the product.

The main idea behind this product is to design and create a type of ‘talking tile’ in which the user is able to record their voice and if desired, attach an image to the front.

Potential audiences:

  • Young children learning to read/vocabulary improvement;
  • SEND children to assist with communicating (augmentative and alternative communication);
  • Those with memory impairments;
  • Carers for those with Alzheimers/Dementia.

This is an example of the design process in D&T. It can be simplified into design –> make –> evaluate.

To make our product, we need to look into existing products, develop our design specification, plan it, make it and then evaluate it.

design process

Here is an example of how you could embed the sound recording module within a designed product:

1We started off with an initial sketch of our design.

2 We then drew what we imagined the base to look like.

3 After our initial design, we decided to refine it further.

4Then we thought about how our cross section would work.

5After this, we mocked up a 3D design using Tinker Cad.

6We then created a mock-up in cardboard. This definitely allows you to see any mistakes that may be made!

7We made some adjustments to our design, and got it ready for the laser cutter.

8 After the acrylic pieces were cut, we removed all of the protective coating.

9Next, we prepared our circuit to add in a power switch. We also swapped over the record switch.

10Then we connected our components together, and glued all of the pieces.

11And there we have it, our finished recording box. We made a few discoveries along the way, and as such our design changed repeatedly. To add an image or text to this, we could blu-tack it on, or use velcro. It has been a good learning exercise, and upon reflection we would not use hot glue to connect the pieces, as it was messy and we didn’t get the desired finish.

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Halloween: Jitterbug Spider

For this project you will need:

  • A Jitterbug kit;
  • A fresh battery;
  • Paper/Card to make your design or a printed template;
  • Scissors;
  • Paints/colouring pens/pencils
  • Phillips and flat head screwdriver.

Task: To create a Halloween inspired Jitterbug

The Jitterbug kit provides a great opportunity for children to explore simple circuits, motors and the power of forces. The off-center mass, when spun at high speed, creates vibration which causes movement in the bug. The movement can be controlled by adjusting the rubber legs underneath. The bug kit can then be decorated however you wish.


1First of all, we emptied out our Jitterbug kit to check that we had everything we needed.


2We then printed out our template, coloured it in and carefully cut it out.


3To make the legs more ‘leg-like’ we folded them lengthways. We then added a crease about 1/3 of the way along the legs, to add a joint (knee?)


4After this, we lined up the plastic body with our card version and marked where the holes needed to be. We then pierced these so that the bolts went through. Next,  we glued the legs onto the back of the body, adding sellotape to keep them secure.


5We then connected the spider’s body to the plastic chassis. We added the nuts onto the bolts and tightened them.


6Next, we added the plastic tubing for the legs, carefully screwing them on until they were tight.


7 We then continued the Jitterbug as-per the instructions. We used a piece of spare paper to help keep the motor in place it its mount. We then attached the battery leads to the motor tabs.


8Finally, we stuck down the battery box, making sure that we could see the switch!

9And there you have it, a Jitterbug spider fit for Halloween!