richfiles

Made some massive progress on my Instrument Panel build! I have the power supply for the Navball designed, thanks to some major help from an internet bystander! This part of the build stood out as difficult, because it's not simply a power supply that needs to be made, but a line voltage supply with a 400Hz synchronized sine wave output that matches the reference frequency that also goes to the DAC board. In essence, I needed to take an external analog signal, and boost it up to 115 volts AC, but where the AC frequency matched the input signal. That design is now done, thanks to one "Dr. Rockzo". He got curious about the project, and had experience in the field of line level power supplies, and lent a very appreciated hand in designing this circuit! I only know the absolute basics of line level power supplies. They are not my area of expertise. All that remains is to order parts and to tweak a few last second changes to the PC board layout, and send it off to be made, so long as I can budget it. Honestly, just hoping for parts/hours at work soon... Finally got hit hard by the parts shortage. Starting to feel that sting... All the details are in the build thread.

Finally made some real progress again with my Kerbal Instrument Panel... Parts shortage has left me with only a handful of hours of work a month. If I work less, there's more time for projects, but also the looming threat of running out of money, period! If I work more, I can afford to buy all the project goodies I like, so they can sit and collect dust while I sleep off the day's efforts, after a long hard day working. Can never win...

Here it is! The 115vac 400Hz Amplifier. Takes my 10v p-p reference sine wave from my California Instruments 850T Precision Sine Oscillator, and boosts it up to enough voltage and current to drive the Navball! This schematic doesn't show the rectifier or the bulk capacitors that create the +/- High voltage rails, but those portions of the schematic are textbook. Also since added is a resistor and coupling capacitor to a shutdown pin on the primary op-amp. I caught that one. The HV rectification is done at the top. The center area with all the surface mount parts is the primary input. The high and low portions of the circuit are the tri of transistors on the left and right sides. I believe the center transistor may (but I'm uncertain) be involved in foldback of the current if it exceeds over-current limits. I'm not 100% certain on that, but I think that's the gist of it. A huge shoutout to Dr. Rockzo, who decided to clown around with some high voltage analog circuitry after we clowned around about Chrome tabs! I'll try to make sure the files are available, whether he has a repository for the stuff, or whether I set up something. For now, he's happy sharing it. I don't know the exact license, but basically build it freely, no commercial. We've still got a few tweaks... I noticed the orientation of the left set of transistors makes heatsinking awkward. He's flipped them on his file already. I haven't had time yet. I need to do the same, as well as get him my modified files with the shutdown circuit tied to enable. I'm really excited to have this high hurdle knocked out of the way! This simplifies a lot for me, and lets me Finally power up my Navball!

Small update, which may likely lead to a major update soon. The TL;DR is that I posted the schematic above to just the right place... Turns out it caught the attention of an individual with far more extensive analog design experience than I have. They got curious enough about the project that they seem to have taken a genuine interest in coming up with a solution... For the fun or challenge of it. So far, the guy has already reworked the 1977 circuit into a modernized circuit concept, has run the circuit in a SPICE simulation to confirm operation, and verified it can be put together with commonly available modern components. The most expensive part is likely to be a transformer... 120vac primary, 230vac CT secondary. I suppose just a 230/240 to 230CT for other regions of the world. That's probably only a $20 part. I was thrilled just having a circuit that ought to work. Later today, after I got home, and I asked how he preferred to be credited, he tells me that now he's trying to design a PC board for it as well! Like... wow... All this started over a humorous post of how many tabs I had open in Chrome (All of them) That lead to the inevitable question of... my sanity, but then to the obvious question of why... That led to "Interesting..." I'm beyond grateful. even if things don't pan out, I've gotten some great insights out of this! I wish him all the success, cause that translates into success here!

Well, I bought a CPU, Motherboard, RAM, and an M.2 NVMe drive. I was fed up with my perpetual lack of upgrades, and I managed to get some good deals... Only problem is all the money I also dumped into upgrading my old boards, particularly the RAM and an extra CPU, which I'll now never use. I hate selling stuff online. So, the board is a Gigabyte Aorus Elite z490, the CPU is an Intel i9 10900K, the RAM is 64 GB of DDR4 3200 (2x 32GB sticks), and the M.2 is a Mushkin Pilot 2TB. Okay UPS, USPS... I'm waiting! CPU was supposed to arrive today. Tracking doesn't show a single arrival since it left it's origin, and it wasn't ion the mail today. RAM should have shipped last week, but didn't even get sent out till yesterday. Might get the M.2 tomorrow., and the theremal compound still hasn't shipped... I've had the board for a whole week! Hurry up and wait...

I went to a local computer shop because I needed an Ethernet to USB adapter. Decided I'd rather support the local computer shop than help fund another Bezos launch... I know, I know... but still... I got there, and low and behold, what was on the shelf at the shop, but an Amazon Basics Ethernet to USB adapter, plus small markup. Oh well, I needed it, so I bought it anyway. I guess Bezos is funded to launch another day.

I wanted to replace my main computer, which is a Hackintosh built on an i7 3770K, and migrate the old one to my workshop. Prior to all the crazy, I had been planning to build an all AMD build, but then... well, you know... and I never made the purchases. A buddy had been financially struggling, and so I bought his 4770K parts off of him (he HAD recently built an AMD system). I snagged a 4790K CPU, and 16GB more RAM (he had 16GB, and I wanted 32GB). I also bought his 780ti, despite it's age, because the 780ti is the highest Nvidia GPU that is still compatible with Mac OS (Compatible up through Mac OS 11: Big Sur, but not beyond that). My current Hackintosh is stuck on Mac OS 10.10, which is WAY out of date, and is compatible with the Nvidia GTX 980ti by way of a web driver... Apple is currently in an immature little feud with Nvidia, and has not granted code certification for any web drivers beyond Mac OS 10.13 I plan to have an install of 10.14 for 32-bit application compatibility, and a second boot volume with Mac OS 11, to be more up to date... I HAVE to downgrade the GPU from the 980ti to the 780ti in order to have it be compatible with BOTH OS versions! Worse, I have no better card at all that works on the newer Mac OS. to complicate matters, even if I upgrade, I'm limited to upgrade no better than Vega 64, because Mac OS 14 has no support for Radeon VII, RX 5x00, or RX 6x00! I REALLY despise that Apple intentionally killed 32-bit application execution. It forces me to maintain an older install of 10.14 to be able to have something I can boot into for things like older games, where the company is no longer around to update them to 64-bit, for example... but needing to rely on 10.14 holds back how new a GPU I can install! . . . Not as if those are even reasonably obtainable right now... A Vega 64 costs a madness inducing $800-900 these days... USED!!! In the end, the GTX 980ti is gonna end up in my workshop PC, which is gonna just be Windows. It's also likely to get the 4790K CPU and motherboard anyway... It wouldn't make any sense to pair the weaker CPU with the better GPU. Eventually I still wanna build that AMD system, but that won't be any time soon. I set out to upgrade my main computer, but at this point, I still end up with the same old 3770K motherboard... but with a GPU DOWNGRADE, from 980ti to 780ti! I can't win!

I think I've found a promising power amplifier circuit for powering the Navball. It's even period correct! The power supply is kinda nuts... +/-150 volts! Yikes! Well, if it does the job, then it does the job! It comes from a 1977 issue of Electronic Design News, but it is designed to do EXACTLY what I need to do... Provide the powered high voltage 400Hz reference/power output for driving synchro based loads, using digital synchro emulation or conversion. I'll have to order the parts and build it up, and see how well it works!

I lost my cat last year, so that pain is still pretty fresh. It hurts so much when they can't continue the journey alongside us. As much as it hurts us when they leave like that, it's their instinctual way of caring for us in their final moment... They leave us, because their instincts lead them to avoid drawing predators or disease carriers near their family group. It might not feel good when they disappear, as it leaves us without closure, but know that our pets really do love us and care for us. For them, this is how their instincts tell them to show it. Your kitty was thinking of you to the end. My cat was strictly an indoor cat. She leaned up against the door of the back room so it couldn't be opened. I think that was her way of "wandering off"... I was able to slip a plastic panel under the door, to slide her away enough so I could enter. As much as it hurt, I knew she was telling me it was time. I took her straight to the vet.

I am so jelly of CuriousMarc and Fran Blanche, who have both had wonderful opportunities to handle real Apollo hardware! It's always a joy to watch their videos! Honestly, most recently, I have loved his HP 9825 repair series. I have an HP9825 myself, and last I used it, it worked, but now I realize I had better install a crowbar circuit into the power supply (if it doesn't already have one), so if the power supply ever fails like his did, it doesn't absolutely wreck my machine. My workshop isn't a nearly as decked out as his is, and honestly, I don't think I have all the equipment to easily fix mine if it ever releases the magic smoke... At least if the repair is as complex as his repair was. As for noise, syncros would actually be noisier, as I'd need servos to drive them, and they would likely exhibit a small amount of their own 400Hz hum, adding to the hum of the synchros and servos already inside the navball. My synchro emulator circuit is actually a thing that already exists... Problem is, flight simulator hardware is expensive and proprietary, but I know how it works... I literally used to work at a company that manufactured synchros. I want to design my own version that is open source, so people can make synchro emulators on the cheap, without being tied into expensive, closed source proprietary systems. All the parts are electronic, so no noise. The only noise will be what the navball's mechanical components make. I do want to use a proper sine wave generator for the purpose of avoiding the many harmonics of a square wave. My worry is that those harmonics would be audibly amplified by the mechanical hardware in the navball. The digital oscillator I have is old enough to be considered retro tech, but it's a high enough resolution output that even the tiniest filter capacitor will certainly make the output smooth.

Oh man, so he rebuilt the ball... Wow... That's impressive work! Me, I'm dead set on keeping it original, and given that my old employer used to manufacture synchros, motors, and motion controllers, I have the right background for it. The code for the controller intimidates me more than anything... Except maybe the inverter. That's gonna be interesting to build. I need to find an inverter circuit that can take a sinusoidal input and output a true sinusoidal AC supply, at up to 115vac at 400 Hz. My waveform generator is an 11-bit DAC with 2048 steps of amplitude... So it is for all intents and purposes, a legitimate true sinusoidal waveform. Many inverters do modified sine, which is just crudely stepped square waves that have a brief rest at the zero crossing point. I don't wanna use a modified sine wave, cause square waves have terrible harmonics, and a lot of these 400Hz aviation instruments "hum" at 400Hz... Last thing I want is harmonics coming through! Furthermore, I gotta find a circuit that expects an input in those transitional regions... Some types of circuits draw undesirable current when not fully on or off. Whatever inverter circuit I settle on, has to be a true analog amplifier, and not something that expects effectively digital switched states. I've really put zero time or effort into researching that bit, and am only running off vague memories of analog circuit dabbling from many years ago. I'll get it figured out eventually...

In other news... It's not Covid. Still don't know what, but Covid was ruled out as the cause of my brother's kid's illness. Like, I'm grateful that it's not Covid... but it still doesn't change that the kid is sick... and now with an unknown cause. And I'm worried that my brother will now double down on his BS... "See, it wasn't covid." At least I can counter though, with "Well, now you know that the doctors aren't padding the numbers, and they actually are excluding non-covid cases" Not sure if it'll even matter though... **EDIT** It ended up being a case of RSV that got nasty. The kid is okay. My brother's been very quiet lately... It's clear to see he's thinking about a lot of things right now... I hope he's thinking about the right things.

Well, the inevitable happened... My brother, who doesn't think Covid is real, and that it's all just a "nasty flu"... Is fine... His 5 year old son, on the other hand, is likely going to be intubated tonight... Are you proud of your pride now? Was your stubbornness worth it? Who else have you given this to? I am so angry right now, that my hands are shaking... I TRIED, over and over, to explain why all this matters... His wife has been ill, his 8 year old daughter is mildly ill now. His 1.5 year old baby girl is recovering, but was very sick last week. So far, only himself, and his oldest son, are the only ones not sick. His oldest has Cerebral Palsy, can't communicate, can't self regulate his temp, can't walk without a walker, and requires a feeding tube to eat, I... I can't even imagine how bad things will get if his oldest kid gets it... I'm legitimately terrified of how bad it could be. But here he is, the only one who for sure hasn't yet gotten sick yet, watching his pride sicken his whole family, and now hospitalize his second youngest son. I want to know if the pride and the stubbornness was worth it. Will he justify it if his kid recovers? Will he forgive himself if he doesn't? I'm 100% convinced he's still running on pride... he still hasn't told me or our mother. I only know this secondhand... Does he plan to just not say a word if his son recovers? Did he plan to just drop a surprise bombshell on us if he doesn't? Don't let pride and stubbornness rule your life. My brother is facing this almost entirely alone, and I think it's because he's still refusing to let go of his pride.

No kidding... You're not the only one who thought that... Nature narrator: "Here, we can see a low ranked wild UPS driver asserting its dominance by marking a customer's package. The customer had previously coaxed a dominant UPS manager, the local group's alpha, to chastise the lower ranked member of the group. This manner of retaliation is generally ineffective, and is typically only seen in the lowest ranked members of the UPS group. The alpha may choose to either further chastise, or even expel the rebellious driver from the group, should their challenges to the alpha's authority continue."

UPS tracking said my hard drives were gonna be delivered on Monday... Awesome! I know UPS delivers in the afternoons in my area, and the estimated delivery window isn 1:30pm to 4:45 pm... That's a good thing, cause I had to go talk to HUD that morning. They were going over my income, and apparently decided that I made an extra $10k more from unemployment than I actually did! Believe me... I wish I had an extra $10k just laying around... but I don't. and that number grossly affects what I owe for rent at this apartment! I knew exactly what they did though... Cause they did it to me once before! I could even pick out exactly what numbers they based their error on and just do the math to get the exact erroneous number they were claiming... You see, they simply took my Weekly benefit maximum limit, and multiplied it by 52 weeks, rather than actually looking at my net payments and tax withholdings, and adding up those two values, for all 52 weeks. A single number x 52, or the addition of 104 unique values... They chose the simpler option, despite knowing it was wrong! The lady in the office actually admitted that "she expected to see me"... WHY!!! Why do the work wrong, when you KNOW it's wrong, and will HAVE TO BE CORRECTED ANYWAY!?!? Well, that was dealt with. I had originally planned to visit my mother and help her out with a few things on Monday, but with he package arriving, I decided to wait on that, and stay home to babysit the door. I was tired that day, so I even went online and electronically pre-signed the release for the package, just incase I managed to nod off when they came. I watched the UPS tracker, even watched the truck indicate it was at my location... And nothing. I even poke my head out the door a few times, looked outside to the parking lot... Nothin'... Next thing I know, the tracking updates to say "Customer not available at door, package will be left at UPS Access Point next business day"... WAT!?!? Tracking updated at 5:11. I was literally at my door the whole time. I had put off plans to be at said door! I called UPS, and after being spit out and hung up on a few times by a bot, I finally managed to get through to a person at 5:24pm. I explained the situation, and how the driver completely flaked out on the delivery. After a short hold, I was too the driver had been contacted and would return to deliver the package, and that I should receive a callback. I stood in the parking lot, waiting for that truck... After half an hour, no callback, no truck. I called again, got hung up on by the bot a few more times, and finally got through to a human. This time I was told the truck did not turn around, and it was too late in the day to make the delivery happen. They said if I wanted it same day, I could drive three towns over and pick it up from the distribution center (I hadn't slept the entire night... No way I was driving), or they could redeliver the next day, either to my address, or to a UPS Access Point. The person on the phone then mentioned that the reason the package wasn't left, was because (according to the driver) the address was present, but not the apartment number. Suggested that the seller had forgot to put the apartment number on the address. I figured, if that was the case, it couldn't be helped... I said I didn't wanna be tied to my door for a second day in a row, so just send it to the Access Point (which is an auto parts store I know). I went back in and sat down at my computer. I checked my email, and when I saw the out for delivery notification I had received earlier that morning, I very clearly saw my apartment number listed as part of the address... I was immediately back on the phone... At this point, I didn't even know why I was calling. I was just furious and defeated, and whining about it to someone was all I had left. I just wanted to imagine that driver being chewed out by a supervisor for so blatantly and repeatedly jerking around a customer that had waited the whole day for that package. I wanted to yell at that driver, but I just was defeated. I was tired, and I said as much over the phone... That I just don't want myself or other customers to be so blatantly jerked around by what is clearly a load of BS. The driver BSed me. The first agent BSed me, the second agent BSed me... The third agent couldn't do anything really, but escalate my complaints, and I actually thanked them for letting me vent a bit. I knew they weren't any of the ones that had jerked me around before. They suggested they'd arrange a callback by the distribution center manager... I honestly was so tired, I just wanted to sleep, so I tried to say it wasn't really necessary, so long as the package makes it in the end... half an hour, and no callback, so I figure all is fine... and then at just a moment before 8pm, I do get a callback. manager confirmed that the address on the box was perfectly legible and included the apartment number. The driver or the agent... one of the two, just straight up lied about that. I got some basic info on when the package ought to be delivered, and finally realized I hadn't eaten... I knew the Chinese restaurant would be closed Tuesday, so I decided to check if they were still open... They had closed 3 minutes prior... Craving denied, not just then but for the next day as well! Made something quick and simple, and then went to bed, finally. The next day, I ran some morning errands, and decided to do laps through downtown with my Gotcha device to collect inventory in Pokemon Go... The company recently reduced the interaction distance to stops by half, and it means I can barely keep up my inventory anymore without dedicating 1-2 hours a day to just doing laps... It's awful, and I have been playing less, and have refused to spend ANY money on the game. After a solid 2 hours of Niantic wasting my time, I got the notification that my package had arrived at the Access Point. I was only a few blocks away, and swung by... To see this: The box was moist to the touch. It doesn't show well, but it looks like the wet side had been slid, like it was slid through a small puddle. Fortunately, the hard drives are in special hard drive carriers that suspend them far from the box edges, and each drive is individually sealed in an ESD bag. Still, it was downright shocking to see the condition of the box. For it to be moist was weird. Honestly, part of me suspects retaliation. Driver got chewed out, decided to give my box the special treatment... I dunno. The wrong drives, that I had to return, arrived in an identical box. Only difference, was that it was pristine! UPS... did not impress me with their service... The good news, is I finally had all the parts on hand for my NAS server. Last thing I needed to do was salvage the SSD from my tablet. I wanted to upgrade my tablet from 128gb to 1tb, and I figured I could reuse the old SSD as the boot volume for the server, rather than buy a new one. Only problem, is the drive cloning process failed 3 times, and nearly failed a fourth, but did eventually work, no thanks to Windows update trying to squeeze one last update in at the last second. Eventually, that was all straightened up. Only took 2 and a half days of messing around... Now my NAS is up and booted, and I now have the joy of figuring out... How do I NAS? Oh yeah, I almost forgot... I got the quote back from that metal fabricator... They wanted $520 to supply me with the honeycomb pattern perforated brass plate I was interested in. I figured it'd be spendy... I thought maybe $80-$130 tops... $520 though, for two pieces that are 33cm by 50cm... Big yikes! I'm gonna have to turn that down.

How your day went is entirely dependent on whether the magic wand results in frosty beverages, or warm beverages... ... Oh wait... Donkey isn't our protagonist here, is he? Darn... he was so relatable! Visitors from the meddling department are always unwelcome guests when you just wanna get your stuff done. T-that was the message here, right? It wasn't replace everyone around you with a frosty beverage and some pretzels? Yes... Probably yes... I think with some new parts being either way overpriced, or outright unobtainium, more and more parts are being sourced second hand. Lots of places probably have inconvenient ppe requirements that might potentially obscure vision and lead to errors (barriers, face shields, glasses fogging from face masks, etc). They might be understaffed, and just under stress to keep up. Honestly, there's lot's of potential reasons for errors and delays. I was utterly shocked at the time it took to prepare my last Digikey order, in comparison to "The Before Times". I can't fault them. Everyone is dealing with problems. It just was a sudden shock to see how much had changed since my last (pre-pandemic) order from them. As for my own issues... I'm doing a new custom PC case build, and what I need is a chassis that will mount a standard ATX motherboard, with 7 PCIe slots, but those slots need to be low-profile slots. That's not a very common configuration in desktops... Most low profile cases are built for either Micro-ATX or Mini-ATX, and will have either 1, 2, 3, or 4 slots... Not the 7 slots that I'm looking for. Where I know this configuration exists, is in 2u servers that take ATX motherboards. The problem with this is that unless I can find one as scrap somewhere, I'm not likely to get it for cheap. ebay seems to price them at $140-180... $140-180 chassis from ebay, that I'm gonna still have to chop up... or... Janky, cobbled together setup made from chopped up Mini and Micro ATX low profile desktops, salvaged from the local PC repair shop's recycling for free... Hmm... Yeah, unless I can find a scraped 2u ATX server chassis, I think this choice is more or less already made for me...

Yeah... I hope you find a new "Little Buddy" soon... It's been over a year since I lost my little sweetie girl, and I still miss her... She gave me 13 years of purrs and licks... I miss having that... Saw some reports that there may be studies showing that Covid boosters might be useful... Sign me up for Jab Three: The Pokening. Finally, I get to hurry up and wait. I have to return some RAM that was not what I ordered (got 2x 4GB instead of 2x 8GB), and I already sent out those 9 hard drives that were wrong. I don't understand why these big tech orders are getting screwed up so badly... Oh well... Both sellers seem fine with fixing the problem. I did seem to once again prove the universe will find a thing only after you purchase it's replacement. Ordered a bag of rubber grommets for mounting the hard drives... I found TWO bags of rubber grommets that I KNEW I had in my workshop, and looked for THREE times! Where did I find them? Eye level, the shelf right by the door, that I face directly every time I leave the room, right under the 4060 lumen LED light fixture I have installed...

Oh Krakens! I ordered over half a grand worth of hard drives in March, NINE hard drives... And somehow, despite looking them over back when I first got them, I missed the one minor detail that they were not the part number I ordered! I had ordered 9 HGST Megascale Coolspin series drives for an 8 drive high efficiency NAS. The Coolspin series drives are slower, running at only 5700 RPM, but they use almost half the energy as a normal 7200 RPM drive, are quieter, run cooler, and induce less overall vibration in the enclosure they are mounted into. They come highly recommended, as they have the distinction of holding the lowest recorded statistical failure rate out of all drives Backblaze has ever recorded failure statistics for. When I found the good deal on the 12 bay server, I decided I'd order 3 more drives and just fill it out... Well, those three new drives arrived yesterday, and when I set them beside the ones ordered in March, the minor differences suddenly became glaring differences. Checked all the drives, and discovered my entire first order had been incorrectly fulfilled. Every single one of the nine drives were the wrong part number. I had a VERY nerve-wracking night last night, knowing the drives were outside of normal return windows, given the time that has passed since March, and knowing I had nearly $600 tied up into this error. I finally got a message, and the seller seems willing to fix the error, but I'm still nervous. I suppose I'm just gonna have to just hope all goes well, that the seller is true to their word, and that I end up with those nine hard drives safely and quickly replaced.

I bought some RAM in May. It was advertised as 8GBx2 (16GB) Due to having a lot of work, etc, I have not had a chance to get around to testing it or installing it. Looked at the part number... It's actually 4GBx2 (8GB) Saw a company that builds up economy servers for home/small business using older generation hardware. $150 shipped for a 1U rack that has an Ivy Bridge era 4 core Xeon, 14 SATA ports on the motherboard, a 400W 80+Gold PSU, and 12x 3.5" bays + a spot for a 2.5" SSD. Not gonna lie, for a small home server or NAS, that is a ridiculously good price. The catch, it doesn't ship with memory. Also, one generally loads a server board with ECC memory... It will work with unbuffered ECC memory... Now the question is, will it work with straight up non-ECC RAM? 8GB is the suggested minimum for running FreeNAS, and well... I have 8GB of RAM that I suddenly have no other use for, but it's not ECC... And I honestly have no idea if it'll even work on that motherboard or not.

Those are pretty neat, but yeah... 11 discontinued switches at $50 a pop aren't gonna go far... budget wise or quantity wise. They are also center off momentary switches, meaning they are like a button that can be pressed two ways. The (ON)-OFF-(ON) terminology indicates the two ON positions are momentary, or sprung. That's why the ON is shown as (ON). Concord Aerospace has been selling replicas on ebay, specifically modeling the infamous SCE switch that was crucial in saving the Apollo 12 mission (along with some humorous "conspiracy themed" switch panels, directly poking fun at a few conspiracy theories, and donating a portion of their proceeds to charity). The panels they make are certainly pretty cool, but it's not the bulk switches that people like us are in need of. I had been in communication with them back in October over a bulk switch purchase. I had even gotten a price, and I had agreed to it, but I've not been able to communicate with them, either by email, nor through their web form, since after October 2020, so I have no idea what happened. I was ready to send some cash their way, and get a box of switches in return... Never happened. Don't know if there is an email inbox not being read, or if something got erroneously flagged as spam? I've meticulously checked my email, and have seen nothing... And I am very bummed out by this lapse in communication. I've considered trying to communicate with them through ebay, but I have to very carefully word my message, as it wasn't a deal through ebay, and I don't wanna violate any terms.

Interesting development in something that has sat on the back burner even longer than any recent developments! Waaaaay back in 2017, when I did the diode ROMs for the DSKY units readouts, I decided I needed a 4-to-16 decoder to take a simple 4 bit value and decode it into a single output to send to each character select of the ROM... I found some 74HC154 chips that would do the logic decoding, but forgot about the basic issue of driving the LEDs. A digital logic chip won't put out enough current to light the whole display. I figured that I could do a simple transistor amplifier, but basic transistor amplifier circuits are inverting circuits, meaning high signals become low, and low becomes high. This complicates things, as now the 4-to-16 decoders outputs would be inverted, which is not what the diode ROMs require to be driven. Just so happens, I came across a sale at a surplus parts supplier I frequently buy from, and they had packages of 74HC4514 chips for a very good price. I was unfamiliar with this part, so I looked up the datasheet. The chips I had previously bought were active low outputs, which is how the diode ROMs were built to be driven... The problem with the 74HC154 chips, is that when you add a transistor driver to those active low outputs, they will become active high driven outputs The datasheet revealed that these 74HC4514 chips have active high outputs, meaning when fed into a single transistor inverting amplifier circuit, each driven output will become... drumroll please... active low! This is exactly what is needed! Notice how the A0-A3 columns are identical, but the Output columns are flipped opposite of each other? THAT is exactly what I needed! What's even more, is that this 74HC4514 chip has an additional feature... The inputs are latched! I removed the latch information from the truth tables, as it made certain parts not line up, and the purpose of the tables above is for comparison of just the outputs, but basically, these new chips can latch the data on the four input lines (A0-A3). This means that I can now run these chips on a bus, just like the velocity display chips, instead of have dedicated lines for every single input of every diode ROM. Now, since the chips have latched inputs, I can send data over the four wires, to all the diode ROMs inputs at once, and then select just the one that I want to latch with a single latch signal. If I had 4 diode ROMs, the old chips would require I have 16 wires to control them all (4 wires per ROM) and all those wires would have to be held in their states. Now, I need only 4 data lines and 4 chip selects to enable the latch on each. That's not bad, and quite frankly, after learning how straining the velocity readout's latch selects were, I'm actually glad this chip makes this so much simpler!

I just noticed it doesn't show reputation or the old custom titles by our names anymore... Only post count, and a mouseover for some generic "rank", acting as some sort of de-numerated reputation. Really getting tired of websites trying to hide people's numbers... Likes, reputation, faves, subs, whatever... I earned those! I don't want 'em hidden! Websites taking away my dopamine hits, such nerve! LOL I do miss it showing me as a "Spacecraft Instrumentation Engineer"... Edit! It shows reputation again! Was this just a temporary glitch? just recent updates? A change? Regardless, woo hoo! Edit 2! It's all fixed! Woot! Still, it is annoying how many other sites have made these kinds of changes their new normal. Glad these were presumably only maintenance glitches.

Went to my brother's place to install a trailer brake controller onto his truck. His truck looks like a typical mid 80s Chevy, with a lift kit, but in reality, it's several different model years of early to late 80s parts, cobbled together, with a box of unknown era, and a Cummins diesel engine and drive train that one might expect to see under the hood of a semi-truck. The only real giveaway that it's got more under that hood than a typical truck is the dual vertical stacks behind the cab. He has a massive fifth wheel tailer that he uses to haul tractors to and from competition tractor pulls. The trailer brake controller operates four electric brake units on the trailer's wheels whenever the truck's brakes are pressed. This gives 8 wheels of stopping power, vs just 4 wheels. This should have been a simple installation... It was not. Turns out, that when you combine parts from an 83, an 85, an 87, and something from probably the late 1970s... etc... There are sometimes differences in things such as the wiring harnesses... Turns out whoever wired the box onto his frame failed to take this into consideration. The trailer lights weren't working when plugged in, and the tail lights themselves were screwy. Turns out the right turn signal was wired to the reverse lights, the brake light signal wasn't even hooked up. There was no wire for reverse at all, and left turn signal and the running lights were the only things wired right, except half the running light bulb sockets were not even hooked up. Also, my brother's dog Leeloo is adorable, but good Lord, she just wanted to play with the new visitor (hint, it was me! ) I got the face lickies cause it turns out that a hyped up pupper can crawl around under a truck way better than I can! There was no escape from sloppy doggy kisses! At one point, I banged my knee on the trailer, then about an hour later, Leeloo used that very knee as a launching point to jump over me, as I was lying under the truck! Max pain inflicted! But yeah... I am definitely SORE... I got that second day soreness blues... I'd love to just crawl back under the blankets and sleep off the bangs and bruises and over-stretched joints and muscles... Alas, I should not, as I have circuit boards I need to solder for work. Also, a word of advice... don't lie under a truck, face up, when someone uses an impact wrench on a bolt on said truck... that's a good way to get a face full of road dust.

So, this is going to be the velocity readout for my Kerbal instrument panel. When I tested this all out on the breadboard, it worked perfectly... I verified that all digits worked, and that I could set the binary input to any valid input, and press the latch button, and set the digit. It was simple! It worked! And so I built it... Aaaaand nuffin' This is so frustrating! what's more, Is I think the unit is fine, but I that my tools are trash. Specifically, I think the breadboard may be screwy. I've had it since I was a teen, back in the 1990s. It's warped, old I'm getting a weirdly high voltage (1.41 volts) when I should read near 0, but it's literally the same pile of parts from the other day testing! I can even pop a module out of the socket and plug it back in and it will load the correct character being sent on the data bus! Literally "Have you tried turning it off, and then turning it on again?"! I figure there might be some leakage in the breadboard, or worse... leakage in the newly wired harness! If there's a problem in the harness, then I can't for the life of me find it... Continuity checks out... I just get a weird voltage on the latch input. Again... I keep coming back to the tools failing me. I just have no idea...

I don't get it!!! I have double, triple checked every wire, and I am having issues with his assembly! The craziest part, is if I preset the value, then unplug and replug a display module into the socket... IT LOADS THE CHARACTER!!! Literally "have you tried turning it off, then on again?"!!! I'm noticing that the latch buttons and the pull up resistors I'm using are all resulting in an unusually high voltage for ground (1.41v), and that is definitely not normal... Yet these are the SAME resistors I used yesterday, and the SAME resistors used on the SAME breadboard to pull up the data bus signals as well, and those pull down to <1v when low... I'm actually starting to suspect the breadboard itself might be defective... It's the same breadboard I used as a teen, back in the 1990s, and it's warped and old, and the portion I used for the latch pushbuttons is a different area than what I used before... Interestingly, the black module loaded characters just fine. Anyway, I either need to retire this old breadboard, or build a buffer circuit to make sure my low signals are 0 volts and my high signals are at 5v, and that there's no ambiguity at all in the signal integrity. It's just frustrating to have issues like this, and know 95% it's probably just worn out tools, and have that lingering 5% wonder if I'll end up finding an error this time if I just do a quadruple check... This is probably one area where building from mental plans probably doesn't help... If there are any errors in the construction, actually having it laid out of paper would certainly help with troubleshooting... A design like this though, I almost never put to paper though... It's just frustrating when things don't work... This doesn't actually happen to me often, so it's easy for roadblocks like this to feel really intense... Anyway, the way this is configured, there are 7 data bus lines (the number only digits only use 5 of the 7 bits). Each of the eight number digits has it's own unique Latch Enable signal (this is the signal I'm having issues with on my test setup right now). Furthermore, the black alphanumeric module has 2 address inputs to select which of the four digits to update, and it has a Write Enable to write the new digit to the display. This comes out to a total of 18 digital signals to control this... And of course both the Arduino Uno and Pro Mini have only 14 Digital I/O... D'oh! This leaves we with a minor dilemma... Do I upgrade to a bigger variant of the Arduino to control this, or slap together some jellybean logic to reduce my pin count. Either way requires that I order parts, and there's no real benefit to one method vs the other. An Arduino Mega might be necessary to have up to 18 Digital outs, and still have room for serial, but that really feels like overkill! In that sense, I feel like some jellybean logic would make more sense: If I feed 3 Digital I/O to the inputs of a 74HC138 3-to-8 decoder, I can decode three address lines into 8 individual one of 8 outputs. If I feed those eight outputs to a bus buffer chip with one Digital out feeding the Enable, then I can stack some functionality... The 3 address digital outs will feed the two address inputs of the black alphanumeric module, and the three inputs to the decoder chip. One digital out will go to the black module's Write Enable, and when activated, will load a character from the 7-bit data bus into the address selected by the first two bits of the three address Digital outs. The second digital out will be the Latch Enable, and will activate the enable chip connected to the output of the 3-to-8 decoder chip. That will pass one, and only one selected output to the one selected numeric display, updating just that one digit. This two chip solution compresses my Digital out requirements to: 7-bits for the data bus, 3-bits for the address bus, and 2 select outputs. That's only 12 wires, and even leaves 2 Digital I/O free for serial communication. With only 2 chips, I'll be able to get an Arduino Pro Mini to be able to handle all the I/O to control this display. That's another thing... I think having clean 0v/5v signals from a proper controller will clean up these weird unexpected mystery voltages that I'm seeing, trying to mess with breadboards and pull up resistors, and what not... At least I hope so. Those digits were expensive! $10 per digit! I don't want to have some kind of fault that damages them. They already get pretty toasty, so I made sure to keep the rear clear, to allow for a heatsink to make contact with he rear of the displays. Also... one more thing... I might have found unobtanium! If this works, it will require hand grinding to make it fit, but I found some hemispherical lenses meant for LED backlighting. I have no idea if they will show digits clearly through, or if they were a waste of $10... But the idea is, if I grind the sides of these lenses to form 10mm wide rounded rectangular lenses, then I may be able to place them over the displays and magnify the digits, like an old school bubble lens display. Again, no idea if it will actually work or not, but I'll give it a shot. It was a $10 gamble... $1 per lens is better than $10 a digit!