DIY head-up display for DMMs - Page 1
Forum section: electronics / testgear

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 06, 2016, 08:07:42 am
content: This is neat - I'd always assumed the optics for a HUD were more complex than this.Although I question the wisdom of keeping a cheap Chinese DMM in your pocket while probing a distribution board.http://hackaday.com/2016/10/05/hackaday-prize-entry-head-up-for-high-voltage/#comment-3223049

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: October 06, 2016, 08:19:35 am
content: Quote from: mikeselectricstuff on October 06, 2016, 08:07:42 am... or wearing a helmet instead of gloves if you fear to touch live wires.

author: TiN
author_rank: Super Contributor
timestamp: October 06, 2016, 10:13:17 am
content: Using both hands to measure mains circuitry doesn't help either.That's why those 2$ alligator clips are made for, no?

author: tszaboo
author_rank: Super Contributor
timestamp: October 06, 2016, 10:18:24 am
content: Although, I would prefer a projection display.

author: Unknown
author_rank: Unknown
timestamp: October 07, 2016, 02:34:13 pm
content: Interesting idea but not for the purpose shown. Maybe they can make it display GAME OVER if the wearer gets zapped. Could be useful for electronics though, how about having a scrolling graph or inputs from several meters or a scope?

author: SeanB
author_rank: Super Contributor
timestamp: October 07, 2016, 07:03:15 pm
content: HUD is simple in concept, the details though of getting it daytime readable and correctly aligned though, along with adapting to night or shifting daylight are not as easy. Also getting a display that is going to be non abberant and also which has no distortion means you need a long focal length in the optics, which invariably means a folded optical path, front surface mirrors and corrective lenses to get the image right, plus an insanely bright light and image source to overcome the losses inherent in the system.Thus a 250W halogen lamp, and stainless steel mask sets for the characters, or a DLP chip with water cooling, is a typical HUD setup in aircraft. Modern ones might use a LED light source, but it will still be high power.

author: Merlot1970
author_rank: Contributor
timestamp: October 07, 2016, 08:50:24 pm
content: Wow....There's no way I would put a DMM in my pocket. He really needs to rethink that process

author: rob77
author_rank: Super Contributor
timestamp: October 07, 2016, 11:05:45 pm
content: Quote from: mikeselectricstuff on October 06, 2016, 08:07:42 ami do have that owon B35 multimeter (bought it just because of that BT connection) and i definitely wouldn't poke in the distribution panel with it. in fact i wouldn't go anywhere near the distribution box with it. and the only way how i would put it into my pocket is powered off without probes2 minimelf resistors + 1 MOV/spark gap is the whole input protection followed with a M7 diode clamping action. fuses are 5x20 size 250V rated.

author: Muttley Snickers
author_rank: Unknown
timestamp: October 08, 2016, 12:06:41 am
content: I recently purchased one of these meters and then promptly sent it back to the local Owon distributor, the meter I received was complete and utter garbage and I was not impressed one bit with either the meter or the distributor, it would display around 370 mV in the DC selection with nothing attached and the null function did very little as the reading would gradually increase, also it would do the same thing after a voltage reference was applied, the Bluetooth app was hit and miss or wouldn’t work at all and the only probes that fitted the meter were the ones supplied if extreme force was used, I still can’t believe that way back I actually recommended this meter to another member for a particular application, shameful.In regards to the topic at hand a thumbs up to the fellow for effort and ingenuity but in practical real world applications the obscuration of a technicians peripheral vision particularly in and around high voltage distribution panels is in my view just asking for trouble and it would not be permitted under my supervision, pardon the pun.

author: tautech
author_rank: Super Contributor
timestamp: October 08, 2016, 12:12:38 am
content: A Mut with super-vision....nah, you're joking right?

author: Muttley Snickers
author_rank: Unknown
timestamp: October 08, 2016, 12:26:24 am
content: Quote from: tautech on October 08, 2016, 12:12:38 amIt can't be too bad sunshine considering that a couple of weeks back I dropped quite a few bunnies up the farm that were all way out yonder just on dusk, damn shame you weren't along as it was a good trip.

author: Howardlong
author_rank: Super Contributor
timestamp: October 08, 2016, 12:27:59 am
content: I bought a couple of those video glasses a few months ago with the intention of hacking them to make a similar device for a scope. The LCD displays in them are tiny. The better of the two took VGA in rather than composite, and was reasonably OK, surprisingly so, for seeing signals from WVGA and even from an XGA scope display despite the downsampling.In the end it was one of those projects that I have yet to properly see through, so the glasses remain in various states of disassembly waiting for a particularly rainy day. You can use them out of the box if you don't mind having to glance backwards and forwards, but frankly not really worth the effort on most occasions.

author: rob77
author_rank: Super Contributor
timestamp: October 08, 2016, 12:43:27 am
content: Quote from: Muttley Snickers on October 08, 2016, 12:06:41 amactually my meter is doing the same with the ~370 mV with open inputs.. but shorting the input with a 10Mohm resistor is bringing it down to 0 mV, so it's just a "cosmetic" issue and it's not affecting the reading during measuring. the device connecting to the meter must a be a BLE (bluetooth low energy) capable and then it works ok.in general it's a good meter for generic low voltage CAT I measurements (and for brave ones even occasional CAT II work is possible) but the 1000V CATIII rating indicated on the meter is a complete bullshit in my opinion.so using it on mains is not recommended and developing a HUD for this very meter is a waste of time.

author: Muttley Snickers
author_rank: Unknown
timestamp: October 08, 2016, 01:18:08 am
content: I tried the two current apps including the BLE on three different devices without any reliable result and even resorted to the apps I had downloaded from their site last year which are different versions and still had problems, I only bought this meter because a client had a particular need to remotely display a value from the rear of a truck trailer to the cabin whilst testing light fittings during fit out, the particular meter I received certainly wasn't up to the job so it went back and not just for that reason.The basic DC accuracy specifications are different between the online manual and the one in the box, not a big variation really but sufficient to warrant concern in my opinion, again the meter I got was garbage and the distributor should have known better than to send or recommend this crap, I researched this meter thoroughly before purchase and in reviews and on paper it looked pretty good, unfortunately that wasn't the case when it was on the bench in front of me.

author: Muttley Snickers
author_rank: Unknown
timestamp: October 20, 2016, 10:20:15 pm
content: I don't understand German but guided by the hand gestures in the video below I can only assume that this fellow had a similar experience to the one I previously mentioned, perhaps somebody could provide a brief translation if I interpreted it incorrectly, coincidentally I used a similar language during the process, no insult or offense intended.Also in the heads up display video originally posted I don't recall the creator showing what would result if the display unit lost connection with the meter, if it were to show just zeros or blank then this could be misleading and potentially dangerous.

author: mos6502
author_rank: Frequent Contributor
timestamp: October 21, 2016, 08:53:56 pm
content: Basically, he's pissed with the buggy software, files keep disappearing, when the software loses connection with the meter the measurements disappear and you can't save the data anymore, and the measurement intervals are wrong.I wonder if he ever heard of the Mooshimeter ...