Video of the working device

Trying to build a cheap Arduino Data Glasses for everybody. Why? I just wanted one.

It's working, and now it can even help to avoid accidents. From the first idea to the working prototype, it took 4 Month

The challenge was, that It should be constructed out of common materials that can be found easily. The project is more about how to build the optical system for this HMD. One thing is clear, you can not just place a screen in front of your eyes, because it will not be possible for them to focus it.

In the logs you can see from the first tests to what I have now.

The optical design was the most difficult part, but I think I found a solution for this. The costs of the prototype amounted to +-70Euros.

And now I have a Head-Up Display For Hight Voltage

## Step 1: What's Inside and How Does It Work?

The received Bluetooth data is displayed, on the OLED display. It's then reflected over the mirror, goes through the lens and you can see the picture in the little transparent acrylic glass.

That is the simple explication. The details are coming now :)

## Step 2: The Lens. the Most Tricky Part

I made the data glasses work, but it was more a trial an error challenge.

So I took a google crash course in optics.

First of all I had to understand the difference between a real and a virtual image with lenses. Then a very important thing is, that a human eye can only focus an object at a distance of min 25cm. And all what I needed was this formula (1/f) = (1/o) + (1/i) where f is focal length of the lens o is object distance to the lens and i is the distance of the virtual image.

Here are the values I used:

with f=10cm and o=7.3cm

you will get an i=-27.03cm (virtual images have always a negative value) and a magnification M=3.7

Lens Calculation Website
http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/image4.html

## Step 3: Alternative Lens

I know that the lens is hard to find. I uses one of a cheap cardboard wich has lenses with a Focal length of 100mm and not like the google cardboard 45mm

UPDATE

I think I found a good solution for the lens. I just checked the physical data (FL = +- 110mm). and they should be perfect. I have no time right now, to test them, but if somebody could do it and give me a feedback, this would be great. A small Fresnel lens should do the job. and they are cheap and easy to find on the internet. And you can cut them with a cutter.

An otherf alternative is a the lens of a head mounted magnifier. Normally they deliver 3 to 5 lenses and one of these should have a FL between 110mm and 120mm which works fine. It's just a little bit heavier and not so easy to cut

## Step 4: Electronics

Here are all the electronic parts for the data glasses

I just used a smaller battery in the final version.

To use the 280mA battery, I had to change the 3k resistor against a 5.6k resistor on the original board. The charging current is now reduced to +- 200mA.

## Step 5: the Enclosure

For the first tests, I used an enclosure made out of cardboard. This was a cheap solution and worked very well

For the final version, I used my 3D printer. The style file has been created in 123design. I need to make a few modifications to the design, but it's not bad for the first try.

## Step 6: Connecting the Owon B35T Multimeter With the Data Glasses

This multimeter has an intern bluetooth 4.0 communication, so you can connect it to your phone or tablet

I had to reverse engineer the serial protocol.

Config of the BT module. I used a simple Arduino program to send and receive Data to and from the module. First you have to set the module to Central.

AT+ROLE1 moule = central

AT+RESET reset AT+SHOW1 show Bluetooth name in response

AT+IMME0 connect automatically

AT+FILT0 scan for devices

AT+DISC? Show devices

To connect to the Owon B35T type AT+CONE0(Mac adress of the Multimeter)

These softwares can be found on github https://github.com/awall9999/Arduino-Glass

## Step 7: The Final Arduino Data Glasses

Here you can see, how all the parts fit in the enclosure. I tried different holders for the acrylic reflector

Here is also a part list:

Link to the software on github

## Step 8: Pictures and Videos of the First Steps

Test setup with different lenses

First bluetooth test video

One of the prototypes video

Things to do:

• Finishing the Software, to auto connect to a Owon Multimeter
• Adding a battery indicator in the display. (The BLE module has this feature)
• Building different reflectors with tint and mirror foils, to make the glasses work in a bright area,
• Reducing the weight and redesigning the enclosure.
• Testing with a smaller 0.49 inch display.
<p>what is the power for this lens ?</p>
<p>It's a Plano convex lens with an focal length of 100mm</p><p>Regards </p><p>Alain</p>
<p>thank you </p>
<p>Congrats! Passion is everything! Awesome project and documenatation.</p>
<p>Yo man ;)</p>
<p>A well deserved grand prize win!</p>
<p>Thanks, I verry proud about it</p>
<p>It always makes me happy to see a grand prize winner that totally deserves it, no doubt about it. Well documented, interesting, and genuinely useful, good job!</p>
<p>Thank you.</p>
<p>Grand prize on Epilog contest! That's great! This is pretty good project, too!</p>
<p>Scratch that &quot;pretty good project&quot; I watched the vid and this is AWESOME!</p>
<p>This reminds me the pyramid hologram, but if I am right the pyramid hologram can not be seen in the daylight does this project have the same problem?</p>
You're right, It's based on the peppers ghost effect. like all the pyramid hologram systems.<br>In normal rooms, there is absolutely no problem. If you look at a window the picture disappears. That's not really a problem. If you use a small plastic mirror instead of the acrylic glass, it works also in a bright area.
<p>Hi awall99!<br>Thank you for such great instruction!<br><br>I had a physical question in mind, maybe you know more about that.<br>What is the actual purpose of the lens?<br>I mean, is its primary goal is to match the image to suit acrylic glass rectangle, or its primary goal to focus the image to infinity (so your eye sees the image without need to refocus on acrylic glass)? <br>Or these goals both are primary for lens?<br><br>Thank you!<br>Daniel</p>
By the way I noticed that my nearsightedness glasses are actually reflecting pictures even on daylight!<br>
<p>This will remove the &quot;see through&quot; ability of the glass. What about a prism?</p>
<p>awesome , can you plz share the program?</p>
<p>That is simply awesome!</p>
<p>Excellent work, kudos to you, Sir. I like it very much!</p>
<p>It seems to me this is a HUD device:</p><p><a href="https://en.wikipedia.org/wiki/Head_up_display" rel="nofollow">https://en.wikipedia.org/wiki/Head_up_display</a></p><p>And the following HUD patent is expired:</p><p><a href="https://www.google.com/patents/US7982959" rel="nofollow">https://www.google.com/patents/US7982959<br></a></p><p>I am building one. I will post back the results.</p><p>Thanks for this very interesting project.</p><p>Ed</p>
<p>you should patent it ....GG</p>
You mention to make it so can see when is bright out. One of two ways to solve this and keep it see through. Have an interchangable display tinted and the other clear like you have. The other is to have a clip on tint. And when way to bright and seeing with both eyes not needed could use a mirrored display either clip on or replaceable.
buenisimo me gusto muxo tu proyecto
i always wanted one.. thankyou sir.. awesome
<p>Congratulations for the really hard (and patient) work you made with this!</p>
<p>Nice use of a reflex sight concept.though using a Fresnel lens might be a bad idea... I tried making a gun sight using the same concept with a fresnel but it was bad since the ridges would cause glares and often blur up the dot (in my case) and the oled (in your case).</p>
<p>in the end i bought a 5\$ binoculers and used it's lens</p>
Wonderful concept and amazing business case. I''m thinking about having a display of bike dashboard in helmet
Simply genius
<p>nice and love this idea!</p>
<p>simply brillint </p>
<p>Amazing! Im working on a device that can show data with this proyect's principles.</p><p>Really grateful for this.</p>
<p>I think what lots of peeps are missing about focus is, you can simply slide the whole device back or forward a bit on the glasses arm to adjust the focus.<br>Yes it would be only an incrementally small amount, but you have focus adjustment never the less. <br>You could also add a secondary lens between the mirror and the OLED display to change focus. Put it on a grub screw or friction slide to hold it's position.<br>Such a lovely solution to the &quot;have to look awake to view the display&quot; issue. All of us that use multimeters and other such test equipment have all had, or do have, the same issue.<br>Love this idea!</p>
<p>I could have used one of these for the past 30 years. Too many times my probes have slipped while turning my head to read the display and when playing with telcom 48 volt lines this can be scary. This may be the project that justifies me buying a 3D printer. </p>
wow. I have to say that this is one of the most useful instructables I have ever seen. I work on electrical a lot between homes cars and tractors and gadgets. There is never a good place to put the meter where you can see it and hold the probes where you need them. Bravo and thanks for being an open source kind of guy. I am going to build this for me and another guy once I get a 3d printer.
<p>Hi all, I updated the </p><h2>Step 3: Alternative Lens</h2><p>Check it out, I think I found a solution for the lens, a cheap fresnel lens shoud do the job.</p>
<p>Does this lens work?</p><p>it is 100mm focal lenght</p><p><a href="http://www.ebay.com/itm/Double-Convex-Dia-50mm-Focal-Length-100mm-Optical-Lens-/301510078528?hash=item463366b040:g:~d4AAOSw0e9Uy61n" rel="nofollow">http://www.ebay.com/itm/Double-Convex-Dia-50mm-Foc...</a></p>
hi. the fl. is Ok, but this one is made out of glass. I am not sure if you can cut it in a rectangle form :(
What does the voltage meter say about his power levels? <br><br>IT'S OVER 9000
<p>SO cool!</p>
Surplusshed.com is a great source for small lenses of all types and small front-surface mirrors. This is hard-to-find stuff in small quantities, but they seem to have everything available in quantities of 1. A lot of it is really high-quality surplus from science and lab companies like Edmund and Jaegers. They also have a lens finder function where you plug in focal length, diameter, etc.
<p>truly inspirational and functional ! would have used this a number of times when i was a sparky </p><p>thanks for doing what you do!</p>
<p>Suggestions:</p><p>For the mirror, try a first surface mirror (if you can find one small enough) or a small prism; cheap mirrors (second surface) cause optical aberrations (double image, edges, etc) because the light has to travel thru the glass before hitting the silver surface, and back out.</p><p>For the front &quot;eye-reflector&quot; try a piece of slide or slide slip-cover glass (for the latter, it will be very delicate - a frame for either might be in order). Another option would be to try some optical-quality polycarbonate sheeting material (this stuff may not be cheap).</p>
Hi, you're right. the plastic mirror generates a double picture, but it's nearly invisible in the reflector. prism was an option to, but hard to find in my hardware store :) and one important thing here is the weight. you can not attach 80g on one side of your glasses.
Here's a pair of 10x10x10mm optical glass prisms of Aliexpress:<br><br>https://www.aliexpress.com/item/2pcs-25-25mm-K9-Optical-Glass-Right-Angle-Slope-Reflecting-Prism/32654422590.html<br><br>\$12.98 USD + free shipping<br><br>It doesn't mention the weight, though - but for the right-angle reflector before the output aperture/reflector it might be something to look into for the next version? Maybe any extra weight could be offset with a change in the holder/mount (less infill, thinner walls, etc)?<br><br>Sure - not something you can find just anywhere (certainly not home depot or harbor freight!) - sometimes these things you have to use other sources (I was going to mention Edmund Scientific Optics - but they aren't cheap, and probably overkill anyhow).
<p>I started 3D printing, and i already have the parts at home, but I can&acute;t find a lens with the needed focal length! Where did you get yours from? And can you tell me the size of the lens (measurments of it) so I can look for the right size? Thanks a lot :) I really love the project! </p>
<p>There are articles around on casting acrylic lenses with just about any focal lengyh you want.</p>
<p>Could you point us to those articles please? This great instructable is useless without a way to get the required lens ;-D</p>
<p>Hi, I added a new step. The lens and what alternative you can use</p>