Blind Assistive Technology (BAT) Sleeve

History

BAT Sleeve Final Design

The BAT Sleeve is a nifty little device I made for my senior project in my engineering classes. It is a sleeve that fits onto a persons hand, and it collects info about the world and feeds it back to the user with vibrating pulses on the wrist. This by itself would be remarkably useless until you consider using it without sight. Now you can suddenly find your way around objects in your way, locate things as small as chess pieces on a table, and so forth.

I came up with the idea soon after I arrived at the University of Southern Mississippi. It was there that I met Dorman 'Mac' David, the first blind man I have ever met. At the same time, smartphones were becoming popular. It clicked in my head that it was odd that everyone now carries these powerful computers, but blind people still had to navigate using a stick! With that in mind, I set about designing the sleeve.

I think I must have driven poor Mac crazy asking him questions about how he gets around. I knew that I wanted something that could be close to the way he navigates already for him to use it easily, so I settled on creating something that acts a bit like a cane does. They will sweep a cane left and right, and when it comes in contact with something, it gives feedback. It was obvious that this had to be mounted on the hand somehow. It was clear that I have to have it 'fail-safe' for the safety of the user. I knew that the response time had to be FAST! Time to build a demo!

Mac trying out my sad looking demo unit

My demo unit I was NOT proud of. It was a Arduino board that was rubber banded (yes really) to a fingerless glove. The slightest bump on this thing would make it die until I fixed it. But it was a proof of concept, and when it was working, it worked well! I used this proof of concept device in a video to raise money for manufacturing the PCB's and other components I would need. Sadly, being a starving college student means that sometimes you need to ask for help. Luckily, I was able to raise enough on indiegogo to be able to build my final project without resorting to selling a kidney.

After raising the money needed for the project, I designed the PCB, streamlined the software a bit, and started work on tearing apart some medical wrist braces to see how they mount to their hand. My mother ended up putting together the fabric parts for me with me hovering over her in the most annoying fashion. Then I set to work soldering and assembling the components. Without to much trouble I ended up with a final project.

My sleeve was then entered into the USM School of Engineering Design Competition where it won first place. I have to say though, the other projects people worked on were really neat, and I feel honored to have those students as my peers!

After submitting my project, I learned about the fantastic project called Tacit. It is the same general concept as my project, only with some differing ideas. It is the work of the ingenious Steve Hoefer, and you can view it here. By all means, mix and match our designed to find something that works well for you!


I have since graduated school, and have made the decision to publish my design. Beyond that, I am making a new, simpler design, that I hope anyone can make. I want to be like the painter Bob Ross, only with electronics and computers. Not just make wonderful things, but inspire YOU to do the same, and encourage you to modify and re-post your own wonderful designs.

So tomorrow we can get started on making a happy little BAT Sleeve! Coming up tomorrow? The parts list!

Parts List

Today I'm going to give you a run-down of the basic parts you need to make the electronics for the BAT Sleeve. Because I know a lot of you are new to electronics, I'm sticking only with the electronics, and not the stuff you need to make the the sleeve they will mount on. Not to worry, that is coming later in the week.

Things you will need...

You need a micro-controller. This terrifying sounding thing is essentially the brain of the device. For this design I'm using an Arduino Duemilanove that you can buy from Amazon by going here.

The Arduino Duemilanove, the 'brain' of the project

The Arduino platform is a neat piece of hardware, designed to be easy to use, and there is an AMAZING amount of documentation on the thing. This is our brain, go get one for this project.

 I don't want you guys to have to do fabrication of any fancy boards for the electronics, so this design will be using a solderless breadboard for the wires to connect to. This makes it so that you can quickly hook up and unhook wires, do fast modifications, and so forth. The one I used you can find here.

Solderless Breadboard

We need power for the device, so for you guys I picked out this 9V adapter. It will work great with 9V batteries. On mine, I took a more difficult route that involved stripping wires and creating connections, but I can assure you that this adapter will work fine for you. Get it here.

9V Power Supply

We need some way for the Arduino to be able to pick up information about the world. For this we will be using a PING))) Ultrasonic Sensor. This thing sends out high frequency sound, then analyses the echo to figure out how far away objects are. Also, not to worry about guide dogs, the sound frequency is so high that even dogs can't hear it! You can pick up one of those here.

PING))) Ultrasonic Sensor

That does it for the major stuff. You will need some other things though. You will need a small speaker, and by small, I mean SMALL! I was able to get mine by going to Radio Shack and looking through their parts bins, but I can't seem to find it in their catalog. Just ask the clerk for a small speaker for an electronics project and they will hook you up. Unless you feel comfortable soldering, make sure that it has two wires coming off of it.

You also need some wire. While you are at Radio Shack, pick that up. I recommend wires that have been pre-cut with terminating ends for breadboarding. Normally they come that way in a grab bag for only a few dollars. To see what I'm talking about, go here, but I can assure you that you don't need nearly that many wires!

You will need a USB cable for programming the Arduino. The one off the back of your printer will work just fine, so you probably don't need to buy one.

You need at least one 9V battery. Better get a couple though, nothing like having something not work, only to discover that you had a dead battery!

As far as electronic parts go, that should be everything you need.

Tomorrow we assemble the components! Finally we get to have some fun!

Wiring

Today we will be assembling the electronics for our glove. It won't be quite ready to play with though, tomorrow we will still have to program the little guy, but once the programming is done, you will be finished with the electronics completely! Lets get started!

The first things we need are your Arduino, mini-breadboard, PING))) sensor, speaker, and wires. For now, set aside your USB cable and battery pack.

Plug the PING))) sensor into the breadboard so it looks like the photo. Ignore the plastic molding on the sides, that will be covered in a later step.  It is important to note that the sensor needs to be placed parallel to  the thicker groove in the center of the breadboard.

Notice that the sensor is parallel to the grove in the center of the breadboard.

Now we have to do our wiring. Pull out three wires, with the colors blue, green, and red. The colors don't matter, but it will make it easier for you to follow the directions. On the front of the sensor you will see that the three pins are labeled GND, 5V, and SIG. Plug the blue wire directly behind the SIG pin, the green wire behind the 5V pin, and the red wire behind the GND pin. If this is confusing, refer to the photo to see how it is done.

Do it just like this and you can't fail. 

Here comes the fun part. You are going to wire up the Arduino! No need to be terrified, it is actually remarkably easy!

Take the other end of the blue wire, and plug it into port 2 on the Arduino.

Take the other end of the red wire and plug it into one of the GND ports on the Arduino.

Finally, take the other end of the green wire, and plug it into the 5V port on the Arduino.

You can see that all the ports are clearly labeled. 

The last step for today is to hook up the speaker. This is what will be giving the user feedback when the device is in use.

The speaker will have 2 wires. Take either wire you like and plug it directly above the red wire that you plugged into the breadboard. This will ground one side of the speaker.

Take the other speaker wire, and plug it into pin 8 of the Arduino.

Nothing to it!

That's it! Good job everyone, you have just wired up the electronics on the BAT Sleeve! Next time we will program the Arduino, which will give you a working device! After that, I'll show you how to make a sleeve to mount it on the hand!

Programming

Now it is time to program the BAT Sleeve. I will be giving you the actual source code to use which will be free to modify all that you wish. But before we do that, we need to have some software to actually compile the source code and transfer the program to the Arduino. To do that, go here.

This is where we will download the Arduino Integrated Development Environment, or IDE for short.  If you scroll down just a bit, you will see download links. Download the one made for the operating system that you are currently running on your computer. While you are there, look around a bit! There are amazing resources and project ideas on that site for the student who is willing to take the time to look.

Go ahead and install the Arduino IDE now that you have downloaded it. If you need further directions on the installation process, you can find them here, under the heading 'Installation'.

I am going forward with the assumption that you have installed the Arduino IDE. If you have not installed the IDE, you will not be able to complete the following instructions.

Download the source code for the Bat Sleeve. You can find it here.

Open up the ZIP file and extract it to your computer. Make a note of where you extracted it to.

Open up the batsleeve.ino file with the Arduino IDE.

Look for the line near the top which looks like this: #include "C:\batsleeve\pitches.h"

Edit that line so that it reflects where you extracted the source code to. For instance, if you are on Linux and you extacted the source code to '/home/mike/batsleeve', edit that one line so it reads as follows:

#include "/home/mike/batsleeve/pitches.h"

Now that everything is pointing to the right place, we can program the Arduino. Plug the USB cable into the Arduino, and the other end into your computer. Now in the Arduino IDE, select 'File', then select 'Upload'. The IDE will now compile the source code and upload it to the Arduino.

Assuming everything went well, you should hear a tone when you place your hand in front of the sensor. If you move your hand away, the tone should lower in pitch. If you move your hand closer, it should increase in pitch. If something is in fingertip distance, you should hear constant pulses of sound. If something suddenly breaks in front of your hand, you should hear a brief beep.

You can now unplug the USB cable. The Arduino will store the program using the magic of science. If you want, you can now plug in the battery pack to take the electronics mobile.

Building the Sleeve, and Final Thoughts
For the sleeve itself, I can't really give you an exact design, because the sleeve has to be made to fit the person wearing it, and I'm not a master tailor, so I can't really make a pattern for you. So here are some general thoughts....

The end product looks like this..

Finished Sleeve

What I did was this: I cut a piece of neoprene in a shape that would fit the back of my hand. I then sewed the 'soft' side of a large piece of Velcro onto the entire back of that. I then sewed on the straps. Make sure to do some heavy duty stitching here!

After that was done, I put electrical tape on the bottom of all the electrical components, and then put the 'hard' side of some Velcro on them with an adhesive. Make sure to include the electrical tape, many adhesives are conductive and will give you short circuits if you apply them directly to the electronics. Now mount the electronics to the back of the hand.

Using the stuff mounted on the back of your hand as a guide, cut another piece of neoprene to fit over the electronics. Now sew Velcro to the sides, and use this piece as a cover. You are done!

Now you can just plug in the battery, and the glove will turn on. Operating it is simple, the closer the object, the higher the pitch. When something is in fingertip reaching distance, the glove will emit pulses of sound. When the glove senses a new object, it will have an audible beep. Experiment with it to find the best use!

In my experience, I find that finding objects on a table is best done by sweeping the edge of the table with my fingertips till the glove locks on, then moving my hand forward till it pulses. This allows me to find objects as small as a shotglass without knocking them over.

For navigation, sweeping left and right parallel to the floor works well. It is much like using a cane, only with a narrower angle. It works really well! How well? Works well enough to win an engineering design award!

That is the end of this project! I hope you guys are able to make one of these to help your blind friends of relatives, and I encourage you to 're-mix' this project as much as you like!

Also, make sure to check out Steve Hoefer's brilliant project called Tacit. It works in a similar fashion to this project, but with some significant differences in design. I hope someone out there can use our ideas to make something truly special!