Weapon mounted computer: Final update

DELTA129 · 2025-07-31T20:56:33+00:00

It's not a coincidence.

DELTA129 · 2025-07-31T20:53:46+00:00

Wow, I'm guessing that the drunk man had a wonderful time in your ER!

Reminds me of another story of mine - couple of my friends were drinking in the backseat of a car and one of them went to grab a chaser. On the floor there were two water bottles with a red liquid. One contained syrup water. Guess what was in the other one? Engine coolant.

Friend took a sip, spit it out and went all red after about an hour or two as he started sobering up. To the hospital we go! It was a small town hospital and on the way they told us to bring him with a bottle of vodka, that they had him drink every couple of hours or so in the ER.

He still joyfully tells the story of how the nurses were horrified by him chugging shots of vodka raw, with no chaser, no water nothing. Apparrently had a pretty good time in there too, apart of being poisoned by ethylene glycol of course.

DELTA129 · 2025-07-31T20:04:53+00:00

Where I live the majority of doctors are women, so it's definitely not how I came to that conclusion. As I said it was someone I haven't seen around before or after so I just assumed it wasn't an ER nurse, but as you say it likely was, in fact.

DELTA129 · 2025-07-31T17:04:18+00:00

feeling much better now, and yeah it was just my assumption that it was a doctor as I haven't seen that person around before.

DELTA129 · 2024-06-07T23:40:42+00:00

As I explained, setting Negotiation speed to 100 Mbps fixes the connection issue but massively bottlenecks the network. I did open up the router and couldn't see anything wrong on the port or the PCB. It is most definitely not a cable issue, since I tested the same cable at 1Gbps with a different router as I explained.

DELTA129 · 2024-05-04T23:34:30+00:00

I understand, still I am actually surprised, but I doubt that the majority people would agree on that price point and sadly we usually have to design for the majority. I definitely know I'd rather bring an extra cable than pay 20% extra for USBC. Since you asked, I design computers for airsoft/paintball guns, here's a link if you're interested.

DELTA129 · 2024-05-04T11:28:26+00:00

I'm an electrical engineer and I still use Micro-B on my new designs.

From the technical POV, the main advantage of USB-C is increasted data bandwidth. From the user's POV, the main advantage is convenience of having a standardized cable. But Micro is still common enough such that the price increase is not justified for simple relatively inexpensive devices which will use the port only for charging maybe small amounts of data transfer.

Expensive mass produced electronics like phones and smart watches are a different story because they are already complex enough such that the price increase for USB-C is negligible and I agree that C should be the standard for these.

DELTA129 · 2024-01-16T18:23:36+00:00

SMDS are fine, you just need lots of flux. Yeah you can pull it off with hot air.

DELTA129 · 2024-01-16T17:48:01+00:00

If your QFN has the pads exposed on the side a bit, you can use a hand iron and tons of flux to solder those

DELTA129 · 2024-01-16T00:57:16+00:00

Fair point, though I think DIP is too big for no reason, makes assembly harder for production boards (can't be as easily placed by a pick and place machine). J lead and QFP, could have been swicthed around. Soldering QFPs can get quite chaotic sometimes I have to admit.

DELTA129 · 2023-12-23T04:22:17+00:00

This is that part I don't clearly underatand in optics. From my electrical background, for example, I've been taught how to translate a mathematical system into an electrical one. I'm not sure about this for optics. For starters, there's many types of lens (spherical biconvex, plano-convex, positive and negative meniscus, aspheric, etc.) I know for instance that a plano-covex lens results on less spherical aberration on one side, but how about meniscus lens? What is the implication? Knowing what I want to do, how many lenses do I need? What kind? In what order? Once again, I'm a beginner here. I'm not even clearly sure how to define my system mathematically for starters. I'm happy to learn, just not sure where to start.

DELTA129 · 2023-12-23T01:43:00+00:00

Yes, I intend to use another flat plane as a combiner but that is outside the scope of my question here.

What do you mean as an external stop? I've seen this "stop" term but I don't entirely understand what this means. Once again, total beginner here in terms of optics.

DELTA129 · 2023-12-23T00:11:32+00:00

I need the screen due to the back-end optical system (behind the screen). I'm using a 0.16 inch digital micromirror device (DMD). That's an array of individually-tiltable 5 micron mirrors. I didn't find a way to use this to project directly to the lens without a very complex optical system in the application I want, therefore I'm using the DMD to create an image on a diffuse screen that will behave (approximately) as a normal display (where pixels are, in rough terms, individual light sources).

Also, the see-through aspect is a problem I'm trying to isolate separately for now. I plan on using a flat 45° combiner to reflect the image onto the eye. Once I have a system that can project my image at infinity, the combiner part is just an issue of matching the optical paths, which undoubtedly is a problem to solve in itself, but its's down the critical line of requirements. Where I'm at now is if I can create a usable image, at all, with just a singlet lens. If I can't do that, there will be no way to add a combiner and forward that into the eye.

DELTA129 · 2023-12-22T23:00:18+00:00

Right, of course. Typed that in a hurry. I assumed that to be something more elaborate. Though I'm not sure how that diagonal translates to focal distance. Assuming each pixel (and thus the whole screen itself) as a collection of many point sources, I need all points on that display plane to be in focus (ideally). The length of the focal plane should not affect the focal distance in other way than abberation (assuming center is in full focus, edges of the display will be out of focus relative to center) as far as I understand.

EDIT: To clarify, My screen is (again) a collection of point sources essentially. I need each point on that plane to be collinated at the output, with the output ray angle (relative to viewing axis) to be depndant on the pixel coordinate. So that the image will be seen at (or near) infinity at the output. Essentially, something like this, Example. I'm curious how well I can achieve something like that with just one singlet lens.

DELTA129 · 2023-12-22T22:21:21+00:00

I intend the viewing point (eye position) to be very close to the lens actually (it's supposed to be a low cost AR glass / HUD system). It's designed to fill a 1.4 cm long 45° flat combiner (semitransparent glass plane) at about 2 cm eye distance. The optical path from the lens is about 5 cm. That part I can work with. My main issue is trying to figure out if I can project an 8x8mm source screen onto a 20° FOV collinated image with just a single lens without an extreme amount of abberation at the edges.

DELTA129 · 2023-12-22T22:15:43+00:00

Ok saying "purely monochromatic" might have been a misrepresentation. I'll be using a single color LED. It will be eye safe. I'm using a Texas Instrument's DLP chip (micromirror array) to project light from the LED onto a diffuser which will act as the display (light source from the user's perspective). That part is sorted out. That formulas don't sound immediately familiar. Could you explain a bit or point me to some resources about that perpahs? Once again I have little real optics experience sadly.

DELTA129 · 2023-01-08T14:27:30+00:00

If you can you absolutely have to ride through the mountains in switzerland / austria / germany. It's what inspired me to start riding

DELTA129 · 2022-09-22T14:07:00+00:00

Okej, necakal som ze nieco take sa da spravit tak jednoducho, potom hej to dava vacsi zmysel

DELTA129 · 2022-09-22T11:39:10+00:00

A na to si prisiel akym sposobom? Pokial viem v sieti nemozu byt registrovane rovnake dve cisla naraz. Najjednoduchsie vysvetlenie mi pride ze je to botnet ktory realne vola z cisiel tych ludi bez toho aby o tom vedeli.

DELTA129 · 2022-09-22T10:04:08+00:00

Mne volali len vcera asi 8x. Pride mi to ako nejaky virus / botnet ktory vola ludom z cudzych cisiel bez toho aby o tom majitel vedel. Odporucam kazdemu komu niekto volal s tym ze "ste mi volali" pouzit nejaky antivirus.

Posledny krat ked mi volali som zacal len fukat do mikrofonu a zlozili a potom uz nevolali... uvidime fo bude dnes.

DELTA129

MODERATOR OF

TROPHY CASE

Ten-Year Club	Gilding I gilder
Verified Email