Category: Technical

The silicone order’s now arrived, a day late. Will be finishing up that process shortly.

I need to get to the hackspace to double-check a thread type; it’s either UNF or whitworth. Then I can order it. It’s for the high-vacuum station that’ll operate as an optical coater and outer-space environmental test chamber for the open-source space program.

Camera is now “fixed” in that I managed to cut the cheap adaptor ring off without breaking it.

Need to open up the Myvu video goggles. There should be a current-set resistor somewhere on the control board that I can replace to make it run just one display, and make it into a decent starters monocular display for the Raspberry Pi based wearble computer system. Then coding, typing and designing as I go will be doable.

Workshop’s being rearranged since my brother moved out. A new cabinet’s down there (big metal thing and reason why my back hurts so much now), so I’m seperating stuff up properly into tools, consumables and materials (including moulds).

Going to put the camera and phone on charge and see if I can’t also harvest the ornemental plums today too, on camera.

Some hair-dye would be good too.

Hackspace work

Spent the bank holiday monday at the Hackspace. Spent about 8 or 9 hours using the grinder and welder turning the salvaged box-section into the frame for the high-vacuum station. It went pretty well. Everything’s square to within a milimeter or two.

Wanted it done today to show progress before the welding gear goes off to EMF for the week.

I’ll finish it up when the gear comes back next week, or possibly earlier if I get a lift in and bring my own welder with me.

Basically it just needs some tack-welds fully welding up and the beveled console area at the back making up.

Some of the flat bar needs cutting too to make corner supports for the worktop. It’s some nice 1″ thick melamine coated stuff from the woodpile that should sit flush. The chamber base will sit recessed into it and the pump stack will hang underneath.

Some more box-section needs to go at the base too, but will be to support the backing pump and HV transformer, so will depend on where they fit best.

Also need someone to donate a scrap 19″ cabinet I can gut the mounting rails from. I’m trying to build in the facility for extra instrumentation later on.

And here’s a picture of Hipster after his EMF tank moved under it’s own power for the first time!

Identifying meaning of “HD” pin on LCD viewfinder

I’m aiming to finally build a wearable, and managed to find a cheap alternative to cutting a set of video glasses in two for a monocular. I got a broken analogue video camera off ebay that had a colour LCD viewfinder. It was a bit of a gamble that being analogue it would have simpler inputs than a digital camcorder, but it paid off. I received the camera today, pulled it apart and got it running on it’s own. 0.2A @5v with composite PAL input.

There’s a 4th pin on the connector though, in addition to Gnd, 5v and video. It’s marked “HD” on the viewfinder PCB, and I traced it back to the IC where (after going through a SMD transistor) connects to the “HD” pin 30 on the controller IC.

The datasheet for the IC expands it a little that the HD pin is for “HD pulse output”, but I can’t find anywhere that explicitly states what the HD pulse is.

I’m *guessing* it’s something to do with the frame timing since the only other HD I can find in the sheet relates to “Horizontal Direction”.

The IC is a Sony CXA1854AR by the by.

The camera supplies the HD pin on the connector with 4.3v however, or at least seems to. I thought I tested it for voltage with the display disconnected, but I’m not sure now. Rather sleep-deprived.

In any case I’m thinking it’s either a case of the IC pin using the transistor to pull the connector pin low, or more likely now that it’s actually a 5v output and my multimeter detected it at only 4.3v due to the duty cycle of the HD pulse. The HD pulse presumably would be something to sync with the video or on-screen text display. But it seems to display PAL video with no problem when it’s not in use, so unsure.

Really I’d just like it if someone can put my mind at ease on the subject. It doesn’t seem essential, but I’d like to know what it’s supposed to do.

Doom and boom

As mentioned on Twitter, I’ve had some computer trouble lately. And it now looks like not only my original boot drive is dead (gone from stalling to jamming up a different machine in POST), but my motherboard too (since it’s started acting the same with the new HD already!).
Current theories; SATA controller gone bad on one channel & damaged drive irreprably, or possibly (untested) PSU is failing & damaging random parts. Other drives are mercifully ok so far, as is replacement main disk now it’s in another machine. Still, keeping an eye on it.

I’ve spent a fair bit of today rebuilding the machine I had reserved for CNC use into a new workshop PC. I’m not going to bring it indoors because I want to feel like I’ve *gained* something in all this shit, rather than lost & partially clawed back. What I’ll gain is basically the ability to record from a webcam in the workshop. Not much of a thing, but it’s something that will be handy for my visible presence.

I will test the PSU indoors to see if it’s noticibly acting up, but I’m keeping my master storage drives disconnected from things until I have something I know’s stable or have a different backup arrangement.

Don’t chide me for keeping the wrong type or frequency of backups. I know I cocked up the last manual set I tried, and the reason it took a week from drive failure to installing a new one is because I was DAMN careful working out how to make my data innately more secure this time. Before my hardware let me down and threw the whole lot back into the skip of chaos where I have so much experience clawing my way along already.

Current plan is to grab the essential files off the drives, get things working again, back them up, then copy less essential files and do a staged set of tidying up.

Only small issue is there’s no printer down here. Old workshop machine may go indoors to be used just for printing receipts & stuff.

Things will be resolved when I can afford to replace the guts of the indoor machine, providing it’s not just the PSU.