Hackaday Prize Entry: Head-up For High Voltage

[Alain Mauer] wanted to build something like a Google Glass setup using a small OLED screen. A 0.96 inch display was too large, but a 0.66 inch one worked well. Combining an Arduino, a Bluetooth module, and battery, and some optics, he built glasses that will show the readout from a multimeter.

You’d think it was simple to pull this off, but it isn’t for a few reasons as [Alain] discovered. The device cost about 70 Euro and you can see a video of the result, below.

The video shows a common problem and its solution. You are probing a mains circuit and have to look away to read the voltmeter. With the glasses, you don’t have to look away, the voltage floats in your field of vision.

These reminded us of Pedosaglass which we covered earlier. Of course, it used a different optical solution. We’ve also seen Google Glass knockoffs as part of our Hackaday prize entries.

43 thoughts on “Hackaday Prize Entry: Head-up For High Voltage

  1. Great idea, but isn’t mandatory to use personal protections (gloves, mask) when working on exposed wires with current like this?
    Because it is in Europe, even if not everyone does :-/

    1. Yes. You need insulating gloves with mechanical protection gloves above, an insulating mat or insulating shoes and a faceshield (+ maybe safety glasses under the shield) and maybe special clothes (at least nothing synthetic that will melt and burn while sticking to your skin). Even if the installation in the video was not live it is a REALLY BAD EXAMPLE. If the installation was live this guy has no idea what he is doing. Don’t understand me wrong, his display-thing is certainly a great idea, but if you don’t have the knowledge you don’t have to mess with mains voltage. 230V can be letal and an electric arc is also not something you want in front of you (even with safety equipment)!!!

      1. This is no real high voltage installation. The arc is just a video effect. It is a normal 230V/400V household installation (“low voltage”, <1000V). Of course it can give you a nasty shock and be lethal under the wrong circumstances. And safety glasses and insulating shoes are a good idea. But face mask and double gloves are a bit "overkill". At this point in the installation you are already behind the fuses at the building entry and the meter. I think this is considered Cat III or cat II.

        1. Never seen electricians wear a full face mask and insulation gloves when they work on a distribution board of a dwelling either.
          The dudes from the energy supplier/network on the other hand.. when they do connect you to the mains power in the street, they do have that sort of stuff for sure. But even then they usually work on offline gear.

          1. Based only on the accent of the creator, I’d say he lives in the land of 220V mains which is considerably more nasty than the 110V mains found in North America. I’d want to be more careful over there too. In the US, if you stick your finger in a light socket, it “hurts like the dickens”. Over in Europe, it kills you. This is also why LED corn-bulbs are more practical in North America. Regardless, its always best to be careful.

          2. Ive been hit with plenty of 250V shocks. If it doesnt go through your heart you’re probably fine. So you do things with a hand behind your back and proper rubber mat.

        2. > The arc is just a video effect.
          Yes, i was perfectly avare of this.
          >But face mask and double gloves are a bit “overkill”.
          That’s what i learned some years ago in France. If you use a multimeter or tools IP2X (that all these domestic stuff is) is no longer enough to protect you, you may get in contact with live stuff. And if there is a short circuit an arc can occur, you need a face mask/shield to protect against heat, molten metal and UV light. Tools (or even the tips of the multimeter or some sharp edge somewhere) can damage you insulatig gloves, so you need protective gloves over them (but iirc they are now some insulating gloves that are really robust and don’t need extra gloves).
          However MAYBE the norm that defines all this is only applicable for industrial installations, but my common sense says that complete PPE is also a very good idea for working on domestic installations. I mean even a small domestic installation is already fused with 30A, a lot of power… (and the voltage is letal anyway)

          1. Where do you live? In the US a 30A fuse would be uncommon in a small installation unless it was for a specific appliance. 15 or 20A is more common for outlets. In Europe, the current is lower (7 or 8A?) because of the higher voltage, power is about the same. This is actually an advantage of the higher voltage. Less current in the walls means cheaper, smaller gauge wire can be used.

          2. @PhoenixofMT
            I was talking about the “master fuse” for the entire home, here in France 30A is quite common (for small homes). When you are probing on the upper side of the things in the fuse box the current is only limited by this. The wall sockets (? – where you plug your devices in) are 16A@230V = 3680W.

          3. Dang! I didn’t realize just how different it was. In the US a small (or old) home would probably have a 100A service feeding the breaker box, but you’d never try to pull more than about 1800W (110V * 20A * 80%) from a standard wall outlet (and then only in the kitchen or where you might plug in a vacuum). Main exception would be the clothes dryer and cooking range outlets. I think 200A service is the standard on new homes.
            Now I wish I could have watched the local utility upgrade my parents from 100 to 200 Amp service to see what PPE they used (if they didn’t just shut off the whole neighborhood.)

      1. short cut > molten metal > permanent damage to your eyes/skin biggest problem

        Check out some anecdotes of RC model guys who use high power Li-Ion battery packs and manage to shorten them. Some are lucky..

    1. Oh yea… never put a meter in your pocket or hand. And yeas to all the safety equipment. you are dressed like you are disarming a bomb.
      But the Idea is beyond great. if only you could markit within a good price rang. In a small company you would be able to use it At a large job NO Way, wich I think is stupid.
      I hope that some one can put it on the market. I could see it saving lives.
      Geat job. I have been trying to make something like this for a bit but using a kids spy glasses that has a 128 * 128 display and a camera that I cant figure out. If anyone has any info on theses spy glasses I would love it if you could pass it on.

      1. My kids are grown, so I’m not up to date in the spy glasses market. Can you provide a name/part number/link to the one you have? I’d consider buying one for the challenge of reverse engineering it.

    2. Reminds me of the story my electronics teacher told about a GE(?) technician that went to measure AC volts (don’t remember if it was terribly high) with his analog meter set to Ohms. He happened to look aside from the meter as he made contact, meaning his face wasn’t in the way as the meter movement imbedded itself in the wall behind him. He got a sideways promotion to Paperwork Technician until he quit sometime later.

          1. Sorry for late reaction… Actually i didn’t think of the company, i thougt that a “GE technician” is somebody doing non-specialised (=general) electrical work or something like this. :-)

  2. definately like the display part. if i was going to do something like this i think id use it for a heading pitch and roll display for my rc heli. i think the only thing different would be my choice of radio module.

      1. Probably but this has the twin advantages that it’s bluetooth so could be paired with any bluetooth device and it could be taken off the helmet. I leave my helmet on my bike all the time, and with a $50 helmet I’m fine with that, but a, say $1500 helmet, no friggin’ way!

  3. Simple and elegant.

    If this is combined with a barcode/CQ scanner. In the right context, you could look at a code and have data pop up about it in your field of view like the price of an item and inventory quantity in a store. You would look a bit like Locutus of Borg but it could be quite efficient for many tasks.

  4. First of all, this is a great project and certainly not limited to multi meters.
    Could someone explain to me why the video suggested that safety protocols are not followed.
    Please tell me the exact protocol, so I can learn from it AND in which specific situation these are required.

    This seems like a regular 230V power cabinet, despite from the brown wire (which everyone can clearly see that it was put there as a yoke). Wearing gloves only makes the job harder, a face shield?!?! seriously. DO you need a shield like that to replace a lightbulb also? Safety glasses, these are always a good idea, in any job, even for grandma when she’s knitting socks, because… well, you never know. But a multi meter, a device fully wrapped in plastic that may not be put into your shirt pocket, come on, really. Despite from the point that it isn’t as practical as shown in the video, the meter is simply to heavy for the shirt. How much should a person sweat for the moisture enters the inside of the meter the connects to the wires and creates a path enough to kill you… really?
    Perhaps if for some crazy reason, the multimeter explodes, then yes, that isn’t the best place to have it there. But what are the changes. People saying that should also inform all cell-phone owners NOT to store there phone in that same pocket. Because the moisture… the heat… the radiation… the reduced antenna functionality but most of all the battery… ever seen a lithium cell explode/combust. Now that is a potentially dangerous situation!
    COm eto think of it… this man has a battery like that close to it’s ear… hmm… well as long as he isn’t using a cheap chinese charger circuit he’ll be fine… ohh… he is… well, just don’t charge it during use then I’m sure you’ll be fine.

    230 vs 110… it both hurts like hell… you should never touch anything above 50V. If you die or don’t die doesn’t depend on the voltage, stating that 110 is safer because of 230 is just ludicrous. Sure there is a point, the voltage is lower, but it makes the same sense like saying that hitting yourself with a hammer in the face is safer when you use a hammer halve the size. It still hurts and it could kill you when you hit the proper spot with the proper force. A lower voltage of 110 compared to 230 gives you only a false sense of security when it is stated like that, 110 is still dangerous!
    And technically speaking the lower voltage requires the wires to be much thicker, contact resistance of plugs to be much lower switches to be more rigid etc. The higher current needs to be transported properly and the infrastructure to do so must be scaled up by a factor of 4 in order to transport the same amount of energy compared to a 230V system. The larger current could more easily result in fires when the electrical installation is not properly done. I’m not saying that 110v systems are a fire hazard, I’m just saying that 230V makes it easier to prevent it while keeping the costs down. And because costs are always an issue…

    Anyway, great project, informative video, thanks for sharing your project.

    1. Look up “Arc Flash” and you might understand why safety regs fly off the handle a bit. People can (and have) die standing a few feet away from an event, from radiation exposure. Accidentally seeing a video showing the effects has convinced me to stay away from anything greater than the 240V available in my shop. Deadly arc flashes might not even be possible at 240V, but lawyers and safety officers seem to make rules for the lowest common denominator.

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