Mini µCurrent Econo Purple

Note before I start: 1 thou = 1 mil = 0.001 inches

While trying to measure the current draw for a battery-operated thermometer, I found that I didn't get any conclusive results with my multimeter and began to look for one that allowed me to measure microamperes, finding that there were some decent ones for less than a hundred USD. Eventually I came upon the µCurrent™ GOLD and found that to be the best option, since I wouldn't end up with another multimeter laying around somewhere while its batteries slowly die.

When I looked at it at the time, I found that it was out of stock, and since the bill of materials is listed, I decided to make my own to remedy the problem. I first decided to replace the CR2032 holder with one that allows the battery to be inserted perpendicularly instead of parallel because I'm not horribly fond of having a large pad for the battery to contact to transmit power (I blame a key-chain sized garage door opener for that).

I also found the switches to be quite large and pricey (based on Mouser's prices), so I looked for something that was smaller and cheaper, and I found something that fit the description.

I tried to use the same reverse-mounted LED, but found that it needed a rectangular hole, which I wanted to avoid because OSH Park might not fabricate it right. I did find something that required a circular hole, and after a quick question to OSH Park, I found that the pads would be fine with the hole there (10 thou would be removed from the pads adjacent to the hole, which I saw on the board after getting it).

I did find a problem with the schematic, which is that pins 1 and 3 of the voltage monitor IC (TPS3809L30DBVR) are flipped, as pin 1 is supposed to be connected to V- and pin 3 is supposed to be connected to SW2-2A.

I also downloaded the Altium PCB files and had a heck of a time getting the right software to be able to open it to poke around with. There's a few things I didn't understand (the traces that go nowhere and the size of the traces for the current input), but it at least helped with ideas for part placement and certain connections (that wasn't clear to me in the schematic).

Once all the parts were created in my library (which I prefer doing, since I don't trust some of the ones from the manufacturers... I blame the pre-made SOIC-8 footprint from back when I was doing the Logitech Optical Trackman power hack...), I started with the placement of the lesser of the parts and ran the traces to them when I had them in a good spot.

After getting all the air wires in, i did some rough placement for the parts and had a tough time, but eventually got the parts arranged and most of the traces routed. I had to add four jumpers to make it possible, since I was trying to use the same trace width for everything after the current input traces.

During all that, I had wondered a couple times if the trace width made a difference, and while i was fairly close to finishing the board, I went and looked it up. Much to my surmise, there was, and I was a bit disheartened that I wasted all the time I did with part placement and trace routing, since I had to throw almost the entirety of the design out. What I found was that it's better to use thin widths for signal traces and thick widths for power traces, and so for the new design, I decided to use the thinnest possible width (6 thou) for all signal traces and anything higher for power traces.

It turned out to give me a lot more leeway with part placement, though routing V+ and V- still wasn't easy, but I did find a way to route it all without having to add jumpers.

Before I forget, I wanted to keep it fairly clean-looking so no exposed vias on the top of the board. I think the µCurrent™ GOLD is actually a multi-layer board with buried vias since there are two traces that via to another layer to hop over other traces. I can't do blind vias with OSH Park, so it's why I wanted to avoid them, or hide them under the switches.

Anyway, I had to utilise SolidWorks a lot to do the math for me to make all the traces as tight and neat-looking as possible (I was also doing this before the redesign). I could've done it all by hand, but it's a bit more time consuming than just drawing it and making all the necessary relations. I also did a lot of manual math with part placement, but it's fairly simple, since I just spaced things 6 thou apart to make it all compact.

Oh, the big white circles are just a reference to keep parts away from the boss of the box I used, and the traces that cross into it aren't a problem, since it's nothing compared to SMT parts.

Once I was done with the part placement and traces (or at least I thought, look at the pad next to 1B of the "upper" switch and you'll see a couple of air wires there), I began cleaning up the non-essential items like the other two mounting holes, the top polygon fill, and the silkscreen. I was pretty much done (again, I only thought I was), and was fairly pleased with the result.

If I remember right, the redesigned board is slightly smaller than beforehand.

Anyway, I noticed the airwire and fixed it (again, using SolidWorks to math the trace nicely), and checked the size of the boss of the adaption plate I was making.

I then did some fine-tuning of the silkscreen before I was happy with the result.

Before and after ratsnest tool.

I then uploaded the board to OSH Park and checked it before ordering it with a couple other boards.

Ordering the parts was an interesting ordeal, as I had found the 0805 case, 10 ohm, 0.05% tolerance SMT resistor on Digi-Key (Mouser didn't have it) when I was getting footprints, but never paid attention that they didn't carry them in stock. I found that Element14/Newark had them, but didn't feel like messing with them (I blame bad memories with the original Raspberry Pi model B), and decided to try out Arrow Electronics. I was actually surprised because they offered free shipping, and so I ordered three of the resistors from them so that I could fill that spot on the other two boards.

For the output amplifier (LMV321AS5X), Mouser had happened to run out of stock of them while I was ordering, and luckily Digi-Key had them in stock, and I placed an order for three and paid a bit less than three USD for shipping, which was nice.

I had to change the CR2032 holder to a different package (from tray to tape and reel) so that it would ship with the other parts from Mouser, but other than that, there were no other surprises.

I also ordered the adaptor plate from Xometry (as well as a couple other items) and had it made out of ABS-ESD7, which wasn't more expensive than the "first available" or cheaper ABS options.

I obviously received the boards back first, and then set them at my solder station after taking some pictures. The "main" cluster of parts was going to be hell to solder when I looked at the board, but I figured if I solder the ICs and then solder the other parts around it, it should be fairly easy.

The usual set of pictures.

I could've started soldering all the parts, but I wanted to get it all done in one go, so I waited until I got my Xometry order. It was estimated that it would ship 22 May, but I ended up getting it this past Thursday (18th), and with my friend needing time to himself to catch up on a project of his, I decided to get this thing soldered and assembled today (20th).

Oh right, I offloaded the banana jacks from the board to make the board smaller.

Anyway I first soldered the 18 gauge wire to the banana jacks and covered the joint with heatshrink before setting them aside to work on the board itself.

I first started with the speciality 10 ohm resistors and the output amplifiers on the extra boards so that I can shove them into ESD bags and get them out of the way.

R9 and U2 populated on the extra boards.

I then started with my plan to start with U1, and found that I couldn't find the silkscreen dot for pin 1, and after looking at the board in EAGLE, I found it was the one "underneath" the "1" of "U1". I dropped some solder down for pin 1 to make it easy, and also dropped some solder down on pin 1 for U4, though the dot was fairly apparent.

I then soldered R5, then U4, then C3 and C4 (I think). Pretty much I kinda worked my way outward from the inside, though partway, I decided to get the "stray" and "leftover" parts out of the way (R1, R9, R2, and then U3, D1). I held off with R4 because I got confused with the blinker/metronome project.

The LED was somewhat interesting to solder, since I didn't want to use my standard method of putting some solder on the pad and tacking the part to the board before fine-tuning the position and such, regardless I got it to work. I probably could've just used that method just fine though.

The battery holder was interesting since the pads are the same size as the tabs, so I put a bit of solder down, put the tab on top, and then heated the tab up until the solder flowed and I got it into position. I forgot about the other tab and removed the holder before putting a slight bit of solder down on the other pad and re-soldered the tab. I then heated the other tab and applied another slight bit of solder. I gave the holder a slight nudge with my finger, since I wasn't sure if it was soldered, and since it didn't budge, I set the board down to figure out my problem with R4.

After digging through the list of parts of the invoice, I realised that the LED I used isn't any difference in forward voltage or forward current, so I went back and soldered the final 270 ohm resistor to the board.

Components soldered.

Since I didn't get a good opportunity to talk about the adaptor, I'll do it before I move on. While I had designed the board to use the lid holes of the box I used, I wanted it to look nice (and didn't feel like trying to nicely drill holes for the banana jacks), I decided to make an adaptor plate to make it easy and nice. I first used the data sheet dimensions, but eventually loaded the 3D model into SolidWorks and pulled some measurements out.

I added some 0.15mm bosses to one side where the PCB sits so that the top of the PCB would theoretically be flush with the edge of the box. I also added some countersinks so that I could use the flathead screws that come with the box instead of having to find something to shove in there. For the board screw holes, I made them 2.5mm in diameter so that I could use a M3 - 0.5mm tap to thread the holes so I didn't have to use some nuts.

I added a cutout for the wires on one side (voltage out), since they were at the edge of the board, and would be inaccessible otherwise. I also did the same to the opposing side so that it wouldn't matter if the plate was rotated 180 degrees, and to shave off some costs.

I spaced the holes for the banana jacks equally, so that it would be centred between the outer edge and the inner edge, and divided equally between the width of the plate.

I also added some arches below the long strip, but removed them when Xometry added about five USD to the price.

After getting the part, I had to drill the board holes out to 2.5 since they seemed closer to 2mm (or smaller) and then tapped the holes. I then checked the fit of the banana jack holes and had to file the hole out a bit so that it would be easy to insert the banana jacks, but still give a snug enough fit.

Top view, bottom view, after tapping, and after filing. I used the torch for the last two pictures to try to make the features a bit more clear.

While it would've looked nicer without the hatching, there's no real easy way to avoid that with FDM-style 3D printing. Luckily, it's uniform, so it doesn't look horrible.

Anyway, back to the assembly. I attached the banana jacks to the plate before I found that the 18 gauge wire didn't fit into the hole, which was annoying since I had already shrunk the heatshrink. While I could've sworn I engineered it for 18 gauge, the best option was to use smaller gauge wire (multimeter lead wires are usually 18 gauge, which is why I chose 18 gauge). Luckily I had some 22 gauge wire laying around, so it wasn't as bad as it could've been.

After getting the banana jacks situated with 22 gauge wire and heatshrink, I then reattached the banana jacks to the plate and then awkwardly solder the first two wires to the board before finding a better way with the other two (the wires close to the switches would've still been awkward anyway). And once that was done and trimmed, I screwed the board to the plate and bent the wires until the assembly fit in the box without any force.

Top and bottom.

I was also concerned with the clearance between the battery and the plate, but I had no worries when I was inserting the batteries, seeing that I had taken it into consideration or something.

I actually used an "old" battery out of a garage door opener that seems to not like any batteries under 3.1 volts, and since the voltage monitor IC turns the LED off at 2.64 volts, I might as well utilise the battery.

Picture wasn't really necessary, but too late.

Anyway, it was time to give it a power test, and when i flipped the switch, my heart skipped a beat or two in the couple seconds before the LED came on.

Either the picture with the switch at "On" never came out, or I actually did move it to the "Short" position by accident.

Now that I confirmed power, it was time to do the final assembly, and it was a bit awkward since the screws and the lid are both black because it was hard to tell how far I drove the screw in as I was trying to keep it relatively loose to allow the holes to align.

Different angles to view the silkscreen better.

I had also ordered some resistors later (with the parts to hack my headphones to make them balanced) to test it according to the article, but didn't realise one of the values was actually an SMT resistor (and the style I'm not fond of because of the SMT zener diode I use at work).

I had made a board and sent it out to get made after checking the unconnected layer (where the air wires reside). I did this so that it would be a lot easier than snagging some clipped legs from work and awkwardly soldering the SMT resistors together as well as the legs.

Doesn't entirely look great, but I prefer functionality over aesthetics.

The boards shipped Thursday (18th, and I'm thinking they'll be here Monday (22nd) or Tuesday (23rd), and once they're here, I'll get the board together so I can check the Mini µCurent.

I have made a separate page (#link) and added a link to the top menu which contains the bill of materials, the EAGLE file, and a link to my board on OSH Park. I linked the schematic to the µCurrent™ GOLD, since this isn't any different, and I can't include any specifications or fancy noise pictures because I don't (think I) have the capabilities to do that stuff... It should (in theory) be the same anyway.

I plan to give away the extra boards with the two parts soldered to them to whoever wants them at no charge (no addresses outside the States please), just leave a comment here and we'll figure it out. Reason why is that it'd just be inefficient to shuffle a few USD around, so I don't mind at all.

Soldering definitely wasn't easy, as I had a few encounters of possible solder bridges, but only had a couple of them which weren't hard to get rid of. Would I hand-solder 0603-sized parts again? Probably only if I had no other options. Would I put pads 6 thou away from each other again? Probably as long as the parts aren't 0603.

This is definitely the tightest and probably the nicest looking board I've designed, and it was definitely worth all the time I spent in SolidWorks to make it so.

I'll stop ranting here for now until I'm able to test it, which I will write more (though you all will be reading this after the entirety of this post is written).

It turns out the boards were sitting in the post box since about 11 yesterday, but I didn't know until I went to check where the package was before heading to bed last night. Unfortunately it's four right now, so I'll wait a bit before fetching the post. At the least I won't have to keep the "I hope it works just fine" thought in my mind for that much longer (though I should say that's it's more of a "I hope I didn't f**k it up").

Anyway, one thing I forgot to mention is that the "B1" silkscreen ended up getting covered by the battery holder, since I forgot to flip the orientation in my head since it's on the bottom and not the top (like in the datasheet). I moved the silkscreen in EAGLE, but it's a shame I'll not be seeing it that way (well, not like I'll be seeing the bottom of the board much anyway). It was actually confusing me for a moment when I was soldering the holder on, since I thought I flipped the orientation, but again, was just that my spacial module crashed with the item while doing the silkscreen.

While arranging the parts, I was a bit hesitant with having the pads for the switch so close to the battery even though the battery is raised up some by the holder. When I was soldering the switch, I found that the legs didn't protrude all that much, so now that I think about it, I doubt it's a problem... Actually I'm gonna go take a quick look before it drives me mad...

Yep, a tonne of space there.

Anyway, I could've also designed a panel that allowed the board to be mounted underneath to lower the outside profile, but that would require labels or something. Perhaps I could've made something with the Front Panel Designer software from Front Panel Express, but I would've had to do a bit more work than I would like to (I would have to figure out all the text positions and how to put it into the programme). I'll digress slightly and say I could've spent a lot less money on the solder station power panel if I had known about Front Panel Express, and it would've came out much nicer as they do print and silkscreen. C'est la vie.

I was worried about the strength of the adapter with where the board is and the thickness (why I put the arches in temporarily), but it's actually much stronger than I thought once assembled. The banana jacks feels solid when pressing them down, but considering the location of them, it's fairly expected. It does give slightly when I press down on the board, but it's not all that much. I actually forgot about those worries when I played with the switches after soldering them to the board, finding that they're quite easy to move (I was expecting something like the voltage switch on a PSU for whatever weird reason).

I had also thought of how to make the board even smaller, and the only way would be to offload the battery (and maybe use something like a CR213A, which would probably last friggin' forever if a CR2032 lasts approximately 50 hours of use). Offloading the battery would also ease the traces, as the placement for V+ and V- would be much more flexible, and probably reduce the top-side trace jumps.

The remaining way to make the board smaller is to force the use of an adaption panel and move the mounting holes after redesigning the board after offloading the battery.

I kept the CR2032 because I didn't want to have a battery and battery holder floating around in the box, otherwise, I probably would have offloaded the battery.

On the name, I went with the USB name basis where you have the large and somewhat square type B plug as the norm, which is followed by mini and micro. So since this is the reduced size, it's "Mini µCurrent". I would say offloading the battery would probably be called "Micro µCurrent" ("µ µCurrent"? XD), and then making the board as small as possible would probably be called "Nano µCurrent". Since I won't be designing either board, it won't be my call (cheers if you do design the smaller boards and utilise the names).

On the "Econo Purple" part of the name, since the main distinguishing feature between the original µCurrent™ and the µCurrent™ GOLD is the gold-plated banana jacks, I decided to go along with the schema there and because OSH Park's boards are purple, that's where the "Purple" comes from. "Econo" is (obviously) short for "economic" which just comes from the fact that this is cheaper than the µCurrent™ GOLD itself (at the least for those in the States).

While checking the name of the original µCurrent™ (I was double checking to see if the "™" was there), I over-scrolled (thanks to the hyper-scroll function...) and ended up seeing an explanation of the strange traces. Rather, a question about those strange traces and a reply to that with a video. If you're just reading through here, I won't torture you by forcing you to watch a 30-minute video of David L. Jones jabbering away to get an explanation of those funky traces I saw (or watch it if you'd like an in-depth explanation). Basically they're traces for testing and connect to other traces in the Gerber file of the panellised boards. Luckily, they were nothing I really needed to worry about.

While looking at the Wikipedia article on him, I found out why he uses Altium - it's because he used to work for them (can't complain with free or reduced-price software).

Anyway, it's getting close to six now, so I'll maybe fetch the post in a couple hours (it's 3°C outside atm, supposedly), but I'll quit typing for now.

I fetched the post approximately one hour ago and took the beauty shot of the Mini µCurrent Econo Purple before opening the package. While dumping the boards (and sticker) into my hand, one fell on the floor, which I caught a quick glimpse of, and it didn't seem quite right. After picking it up, I saw that the board was riddled with vias, which I knew wasn't right, and once I looked at the boards a bit closer, I realised OSH Park had sent me someone else's boards.

I was (and still am a bit) quite disheartened, not because I can't get this project out of the way (if I get impatient enough, I'll solder the SMT resistors together and use 22 gauge wires as makeshift legs), but because that someone else has to wait that much longer before they can finish theirs (I'm just hoping their project isn't time-sensitive).

I went and got all the prices together from what I spent, which turns out to be a total of 59.05 USD without the adaptor plate, and 70.77 USD with the adaptor plate. Buying a µCurrent™ GOLD, would've cost me about 63.80 USD (according to the currency convertor thingy at the EEVblog store, 66.36 USD according to Google) for the item itself, and I'm guessing 30 AUD for shipping, so 109 AUD total which calculates out to be roughly 78.14 USD (81.27 based on converting 109 AUD to USD with Google). Since it's out of stock, I couldn't get an accurate total to convert.

Total shipping costs that I spent was 7.84 USD (there's also a total of 19 cents tax, but let's just ignore that since it's not worth mentioning), so subtracting shipping, I spent 51.21 USD (62.93 USD with the adaptor plate).

While I was working on the board at work (during a short break), the electrical engineer was asking about it before saying that it would cheaper for me to just buy it. I knew I could make it for equal or lesser cost, and I did, even with the adaptor plate. I'm debating whether or not to rub it in his face that I proved him wrong. I'll think about that more.

All for now until I'm able to test it (not that anyone's reading this until it's posted anyway).

I got impatient and tested it out. At first I got -600 something mV reading (which would be -600 mA), but found that when I hooked the 47 ohm 1 watt resistor and power supply up, the reading didn't change, even when I swapped the resistor for 47 kilohms. My heart sank a lot and I went over the board layout, schematic and screenshot of the µCurrent™ GOLD.

I stopped poking around a few minutes after noon to go eat and pondered it a bit more, figuring I should check for shorts and whatnot. After a bit of time, I found a short between R12 and R11, and once I removed the solder bridge, I was getting proper readings. I got 111mA for 47 ohms, 111µA for 47 kilohms, and was happy that things were working right. It was time to solder those SMT resistors together, and I happened to have some legs lying at the solder station.

Very resistor, many makeshift, wow.

When I turned the Mini µCurrent back on in the nanoampere scale, I found that it was bouncing around roughly 30-40nA and after I connected the makeshift resistor, it went up to 60 something nA - for reference I should be getting around 100nA. Needless to say that I was fairly ambivalent, since I was happy that it works otherwise, but upset that it doesn't properly test out in the nanoampere scale. While I highly doubt I will ever need the nanoampere scale, it's still sort of a bummer to have something work partway.

Perhaps the solder bridge between R11 and R12 damaged something enough to where it disrupted the nanoampere resolution, but not enough to throw off the other two scales (which should give 106mA and 106µA readings). After taking another close look at it (physically) and making sure there was nothing wrong with the makeshift resistor (I guess my Fluke metre can't measure 50 megaohms), I decided to just leave it be, as I was more wanting something that reads microamperes.

I was going to release the EAGLE file, bill of materials, and 3D models of the adaptor plate, as well as sharing the board on OSH Park, but with how it turned out and the fact that I have no idea what's wrong with the nanoampere scale, I think it would be safest to not do so.

I also was going to give away the other two boards with R9 and U2 attached, but again, I'm going to keep them for now until I find out what's wrong.

Kind of a shame it turned out the way it did, but at the least it's not completely unusable like I thought it was before lunch.

This project was definitely a challenge in many ways, but it was mostly worth the trouble.

I have learned to turn off the top, bottom, via, and pad layers to make the air wires more clear, so I don't miss any connections, and have applied that to the µCurrent tester board and the metronome/blinker board.

I think the other take-away from this is just devising a soldering order when dealing with close or small parts.

That's it for this post and the next one will be the metronome/blinker board when I get the board tomorrow.

P.S.
Oh right, while watching that video, I saw the two traces on the µCurrent™ GOLD that jump topside to hop over other traces, and that it's hidden under one of the switches, so it actually is a 2-layer board.

Digital Audio Players

The article I read is: Does anyone actually use digital audio players?

Short answer, yes - yes there are plenty of people that use digital audio players (DAPs).

You see, we DAP users tend to hide in our little alcove, hidden away from the rest of the world (unless you know where to look).

More seriously, it's true we are somewhat "far and few", but we do exist and we do buy DAPs. Most of us "hide" on audiophile sites like head-fi.org and go to expos like CanJam, but of course, some of us also don't.

I'll quit having fun now and actually rant about MP3 players (coughcoughiPodcoughcough) and DAPs.

If the article author is reading this, I'll inform you that my rants may be hard to follow (and I sometimes never write in chronological order).

Anyway, why DAPs? There's a lot of reasons people choose DAPs over their phones or Apple-branded devices - anywhere from file compatibility to quality of sound. For me, it was mainly because of storage and that I use Linux much more often than Windows; there's also the file compatibility, but I'll get there in a bit.

Originally, I had an iPod (I don't remember what generation, but I think it had an 80GB hard drive), and when it died, I replaced it with one that had 160GB. I think that one died and I replaced it with the "Classic" that had the 120GB hard drive. At some point after that, I grabbed the 64GB iPod Touch (4th generation).

It was fine, it held all of my music (though I reduced the bitrate to save a bit of space on the "iTouch" - what I call it when I'm too lazy to utilise proper nomenclature), and it shuffled all of my songs the way I liked it.

My friend told me about the ColorFi or something sometime before I purchased the iTouch and shoved it into one of my Amazon wishlists before it ended up getting deleted into eternity (became unavailable or something if I remember correctly). It was a very brief touch into the DAP world for me.

It was roughly September of last year when the iTouch began to glitch out much more often than used to, and October I decided on Cayin's Spark N5 DAP, which apparently had a slightly better firmware than Fiio's X5 II.

Roughly 256GB of music at maximum with two micro SD card slots? Hell yeah! No longer have to boot into Windows and wait forever and a half for iTunes to down-sample and sync my music? Hell fckin' yeah! Better sound quality? I'll take it.

I'm not an audiophile like others can be, and so it's not a huge deal to me.

Well, I forgot that with the ASUS ZenFone 2, I bought a 64GB micro SD card to load all of my music onto (without resampling) and attempted to utilise it as a music device, but it didn't work. Why? Because there isn't a good music application for Android (at the time) that allowed me to do the same thing as the iTouch. Google's Play Music application (or whatever they call it) couldn't handle adding 8000 something songs in the play queue, and all the others I tried weren't much better. I think I ended up using it to listen to a specific song, since I never liked disturbing the iTouch's random queue.

There was also something at some point that I wanted to go with an open source codec (Ogg Vorbis) with my entire music library, but since I couldn't use it with iTunes, I set the idea aside and passively pined to get away from the Apple.

Back to the near past, and the N5 was a pretty decent replacement for the ageing and glitchy iTouch, as the randomisation was okay. What I found was that after a week or two is that I would hear the same songs in the same order... I remember reading somewhere that a playlist on the N5 has a maximum capacity of 1000 for some sort of security issue or something, so I'm guessing it got stuck with some set of 1000 songs and randomised between them. It wasn't too bad though, I usually could skip one or two songs and it would be okay for another week or two.

What was the real problem with the N5 that I had? Electro-static discharge. ESD likes to make everything problematic for everything that isn't protected against it. What happened was that every-so-often, ESD would enter from somewhere and freeze the firmware and I'd have to scramble for the reset button or try some weird trick with the micro USB port and the power button to get it back on. Eventually I kept my SIM card ejection tool that came with my Nexus 5X with me, so when it did freeze, I could just whip it out and reset the thing. I could never pinpoint where it was entering from and understand how it affected it that badly. C'est la vie.

The other slightly annoying thing was that the headphone and line out was the same jack and that I had to change between them depending on what I wanted - I also had to fix this after a full reset. I eventually grabbed a short right angle adapter stereo cable to keep plugged into the port so I wouldn't lose my line out "volume" when I unplugged from my work speaker or from the car; when I wanted to listen with headphones, I just unplugged the adapter and plugged my headphones in (insert Staples button here).

Since the randomization was limited, I didn't care too much if it reset or meddling with it when I wanted to listen to a specific song, but even with "page scrolling" enabled, it  was impossible to get to a specific song while looking through a list of 8300 something songs.

But the main thing I loved about it was the hardware buttons (because the iTouch only has four buttons, none of which contribute to playback functions) because I didn't have to awkwardly try to find the next "button" on the touch screen while keeping my eyes on the road. Shame I realised late that holding the volume buttons on the N5 was the same as previous/next. C'est la vie.

It's probably obvious by my tense that I didn't stay with the N5 and I pre-ordered Fiio's X5 III on the last day of February this year. I finally got it mid-March and have been using it since then. Randomisation function seems to be much better than the N5, though the X5 III runs Android and Fiio's very own music application; however, because of the relatively frequent firmware updates (and also not thoroughly exploring all the options in the application), I've not been able to get a proper randomisation test in. Que sera sera.

From what I've been able to experience, I really love the X5 III. Roughly 512GB maximum storage size (because micro SD cards are maxed out at 256GB at the moment, but it will easily support higher cards when they're available), dedicated previous/next buttons, volume wheel (a bit more on this later), touchscreen, and ability to properly search for songs (albeit slow)? Let's say my reaction was somewhere between extreme hyperactivity and cardiac arrest.

Well, I forgot to say that when I was looking to replace the N5, I was heavily considering the X5 II, but while looking around for a confirmed maximum card capacity for it, I found out about the X5 III and read over Fiio's page on their site about it. Though companies usually try their best to glorify new products, I was quite sold because it was everything I was wanting and needing. (I think this was roughly January by the way.)

Anyway, the power button has a blue LED that indicates power and charge (though I don't think I've ever seen it not blue), which I read that a lot of people don't like, and I see why - it's bloody annoying. There're ways to deal with it, but I don't think Fiio can do anything with at the firmware level, since I'm sure they would've done so by now. Que sera sera.

The volume wheel is kinda nice, but sensitive (like all the other buttons), and also doesn't change volume quickly enough sometimes (which was another complaint I read about). Fiio might be able to fix this at the firmware level by adding a multiplier option so one wheel step changes the volume by x amount. I'm not too concerned with it, since most of the time I'm utilising the line out jack.

Which is what I forgot to add to the list above, headphone and line out are bloody separated! Line out shares the same jack as coaxial out, but who uses that stuff? Well, not me anyway, and obviously line out is the default option.

And as I said, the buttons are bloody sensitive, it's easy to accidentally press a button with or without the vinyl case (it also comes with a leather case, but I didn't care for it. I figured the easiest remedy would be to cut out the button overlays in the vinyl case, and yesterday I decided to do it because I was sick of having to turn the screen on every time for the playback controls. Forgot to say that the buttons and volume wheel can be locked out to avoid the accidental issue. Anyway, it worked pretty well, though I left the power button overlay alone since I thought it was okay (earlier today I decided to go ahead and get rid of it, just because).

If it's not obvious why I was ecstatic for the touchscreen, it's because I can utilise an on-screen keyboard to search for stuff. Though the stock, non-Google keyboard wasn't bad, I ended up installing Google's keyboard (Gboard I think it's called now?) since Google's keyboard gives me more access to accented characters (though I haven't really utilised them in searches yet), and that I was installing Google's Japanese keyboard anyway (might as well make everything match).

I did say the search is slow... It's kinda bad, I'll type like 3 characters and then have to wait for it pull up results. Live searches are good for certain things, but the X5 III can't handle it that well with a large library - I'd like to see them implement a way to turn off live search to make it quicker for users like me to search their music. While it is slow, that doesn't mean I have to stop pressing keys as soon as it lags, nope, I can keep typing and hope I don't make a mistake because that's when I would actually have to wait, unless I know what I hit. Search is perfect from what I tested as searching "fo(u)r" actually brings up the songs and nothing else while "four" doesn't bring any of those songs up. I tried a search for something in Japanese, but it was a unneeded reassurance.

The list of songs is weird and some accented characters don't appear right, but that's really not much of my concern (sadly it's actually faster to search than to scroll with the touchscreen).

Oh yeah, the X5 III also has WiFi and Bluetooth which I was initially excited for (mainly Bluetooth), but now it's a bit more inverted now. WiFi makes the firmware updates easy, since it's less to do than to download it, transfer it, etc. It does have an option for manual updates, but I doubt I'll need it. I was excited for the Bluetooth because Fiio has their own Bluetooth remote for Bluetooth-compatible devices, but the only time I would be using it would be in the car, but the buttons on the X5 III itself isn't hard to remember... I'll maybe pair it with the iTouch or something, we'll see.

My only minor irk with the X5 III is that with the ports on the bottom, the spot I've been using for the DAPs blocks access to two of the three playback buttons since I keep the stereo cable topside when in that little spot. I'll eventually adapt.

I did glitch out the Fiio music application while trying to play over Bluetooth to the Sound Step thing I have, while not important, it was still a sort of "well, there goes that idea..." situation. I'll just use my headphones.

Sound-wise, it seems like the N5 boosts the higher frequencies a bit while the X5 III sounds clearer and more balanced (both DAPs at default sound settings). I eventually got really tired of hearing the same song twice in a row trying to compare the two, and got really bored quickly.

X5 III also supports fast charging (9 and 12-volt charging), and I grabbed my ZenFone 2 charger when I was initially setting up the X5 III, since it would easily keep it charged than a 5-volt, 1-amp charger. It was really weird setting it up because I've gotten so used to it taking a day or two to set up a new (Android) smartphone, but it took me an hour or less and I felt extremely lost.

Oh yeah, there's no accelerometers, so no landscape keyboard for me. Que sera sera.

The X5 III is very slightly bigger than the N5 which was a nice find, though I didn't really care much. Neither of them are as small as the iTouch, but do realise that the iTouch has a smaller battery and less music-related components.

I'll stop reviewing the X5 III here as I kinda went in that direction (if you're still reading this, article-author, I first applaud you, and I secondly re-welcome you to my rants).

I remember something about the LG G6 (or whatever it is) was supposed to have quad-DACs (digital-analogue converter), but from the short digging I did after it was released, I couldn't find such thing. Would I have gotten it instead of the X5 III? Nope.

Anyway before I quit ranting altogether, let's take a brief (and late) introduction to what makes a DAP a DAP. Well, I suppose there's two ways to see this... DAP stands for Digital Audio Player, so in technicality lots of things are DAPs (phones, Apple products, etc), but what do we music enthusiasts and audiophiles consider a DAP? A unit that has good-quality DACs. I think most mid-range DAPs (X5 II, X5 III, N5, etc.) are dual-DACs, where one DAC takes care of one frequency range and the other takes care of the other frequency range. So by that definition, phones and all that stuff is taken off the list because they just have some cheap stuff that sounds decent.

As far as the two DAPs mention in the article, I probably wouldn't buy them mainly because the X5 III has a higher storage capacity capability. Well, considering I already have the X5 III, I don't see any good reason to spend more money for another DAP (considering I've already purchased two).

I did revisit the Ogg Vorbis idea, but decided it probably won't be worth the time for the moment, since that entails converting my entire library. When I build Melty's replacement (possibly an AM4+ CPU when those are out... or maybe AM5), I'll probably be a bit more willing to do so since it'd be a bit faster with multi-threading (along with multi-core processing). The main reason why I originally thought about doing it was because openSUSE doesn't ship with the MP3 codec because of it's non-free status, but after moving to Manjaro, I'm obviously not as worried about it. We'll see what happens later.

Anyway, for those of you who are avid (?) and/or regular readers, you now know a decent amount of my history with portable music players, and for the article-author (again, if you're still here), you now have quite a bit of insight to why people like us prefer DAPs over anything else (even if it is another device to carry).

Also, I was going to write/rant couple days ago when I read the article, but it's difficult to do anything at all when dizziness prevails... Yay, illnesses! (Yay, sarcasm!)

Well, back to the blog's semi-hiatus... Ciao!

Soundcard Switchboard 2

Before I start, I'll post the pictures of the test boards that I was testing the plated slots that I took a couple minutes before starting this post.

Just the 3-up in my hand for a quick picture.You might be able to tell that the slots are parallel to each other, but not to the edge of the board.

Anyway, I had received the boards first with the boards for the solder station, and had set them aside since the order from Mouser was back-ordered. Once I received the parts, I began with taking a bit of time at work to do the switches.

I took pictures as I soldered the wires to the switch. Deformity/dents on the heatshrink tubing on the last couple pictures is from trying to recover the unshrunk diameter of the tube since it shrunk while I was soldering.

Some closer shots. The LED polarity is marked on the plastic of the switch though the LED legs follow the usual "anode leg is longer than the cathode leg".

Obviously I shrunk the heatshrink around the soldered ends.

Both switches after shrinking.

I then covered the wires with larger heatshrink tubing to make it look a bit nicer (though it wouldn't be visible anyway).

Before and after.

I then utilised some larger heatshrink that had some adhesive on the inside to try to keep the stress away from the solder joints. I was lucky that the outside diameter of the tubing was less than the bushing. The adhesive heatshrink tubing took a lot longer to shrink since the wall was thicker and the adhesive also need to absorb the heat to activate.

Before and after. It didn't turn out entirely like I wanted it to, but it at least was adhered to the switch body.

With that done, I needed to drill out the holes in the 3.5" to 5.25" external bay adapter for the switches. The week before I had observed how to utilise the vertical mill at work for basic usage, so I was relatively prepared the day after making the switches to drill the holes into the panel.

I had decided beforehand that I would utilise the vertical mill, since I would be able to keep the holes aligned horizontally even if I was off a bit vertically - I wanted this to look nice. I was also thinking to get a drawing out to have the machinist drill them out for me, but I didn't really want to deal with the awkwardness of asking him directly and/or asking the manager to have him do it.. Anyway, picture time.

Different views of the newly modified bracket.

I also drilled some small holes for securing the cable to the bracket to further remove stress from the solder joints as I had forgotten to mention before posting the pictures (which were done the day after). I next installed the switches and found why I was supposed to drill the holes larger, which is because of a boss of a different diameter that the O-ring fits around. Had I drilled it out to the proper size, the switches would be able to sit flat while compressing the rings, but that didn't happen and I didn't have access to anything larger than a 1/2" drill (I think the datasheet for the switch calls for a 13.6mm hole).

I decided to ignore it and keep working, since it wasn't entirely noticeable, and with the second switch, I tweaked the adhesive heatshrink too much and heard a snap. I think my heart stopped for a moment since I was hoping to hell that the snap wasn't from the LED legs. I took a moment with the semi-broken multimeter (the one seen in one of the pictures from the solder station project thing) to checked the forward voltage, which gave me a reading and drove the LED to light up enough to ease my fears; I also checked the switch, though I doubted the lugs would be able to snap like that - switch function passed. The snap was probably caused by the adhesive detaching from the switch body. I then secured the cables to the bracket once the nuts were tightened.

Front-ish and top view. Semi-broken multimeter in the background of the front view image.

I then reattached the multi-card reader to the bracket before reinstalling it into Melty.

Same views as before with the card reader, and the assembly installed in Melty.

After spending a couple hours cable managing, I found that the Hirose connectors were not going to work with the Iwiss crimpers I currently had, and went with utilising a pair of needlenose pliers to do what I could to crimp them to the wire. After loading the plugs correctly, I shrank the heatshrink tubing before making the power harness. I decided to use red for the cable to the switch on the right side of the case, so that I would be able to differentiate between the cables if I ever wanted to change the button order.

The best-attempt crimp job, finished left switch harness, process of the right switch harness, and the power cable harness.

I then connected the power harness and then tucked the three cables awkwardly "in" the PSU shroud so that they would kinda stay put and not cause too much trouble.

New cable management, 5 volt power for switchbox added, inside shots, front shot (though probably not needed).

I tucked Melty back under the "desk" and hooked her back up before relaxing for the night and the next morning I began assembly on the board.

The usual pictures.

When it came time to the jacks, I soldered one of the three legs to the board and was going to utilise the PCI panel to line them up better when I found out that I screwed up the spacing between the jacks.

This actually isn't the correct panel (this one has 8 holes and not 9), but you can still tell that the spacing is wrong.

I was upset that had made that sort of mistake and decided to set it all aside and change gears to the solder station boards.

I forgot to mention that when I was drilling the holes for the bracket, I drilled out the holes in the correct PCI panel out larger so that the shoulder washers that I purchased would work with it and isolate the sleeve signals from one another. I also bead blasted it and painted it with some matte spray paint, but I never took pictures of it.

Anyway, I took the "wrong" panel to work to use the pin gauges to measure the diameter of the holes and it varied within a couple thousandths. I also measured between the diameters of the holes and also measured between the out-most two holes and divided by 8. I think it was when I was using the pin gauges when I realised the panel had 8 holes and not 9. The difference between measuring one and measuring the total and then dividing by 8 was one or two thousandths difference, so I think I took the result from dividing by 8 since that would be a bit more nominal than just taking the one measurement between two of the holes.

I decided to redraw the PCB instead of trying to fix the current one as I didn't want to have to deal with the existing polygons and traces. Surprisingly, it actually didn't take as long to redraw it, since some of the values would be staying the same between the new and old boards, and I sent the design to OSH Park once I was satisfied.

Before and after ratsnest tool.

I decided to bead blast the "wrong" panel during lunch to get the weird crud off the back (which was also present on the "correct" panel) and to make it a bit nicer. There's still some discolouration from where the crud was, and I'm guessing there was some sort of corrosion going on with its previous utility.

I just don't think my camera likes taking a good shot of the bead blasting.

I had found out that there were cheaper crimp tools to be able to crimp the tiny Hirose connectors, and after finding what it was and verifying in the list, I found it on Amazon and promptly ordered them.

I had booted Melty into Windows to check if I was having the same errors that a friend was having with a game and noticed that my files drive was offline, and after verifying it in Manjaro, I powered her down and investigated. Eventually I found a SATA cable unplugged from the motherboard and then I removed the one above it to plug the one that become unplugged back in (since I couldn't manipulate it back into the port with the one above it still plugged in) before plugging the one above it back in.

I then did a test tug and it became unplugged. I found that the release latch was designed just right so in a stacked configuration like that, the plug above it would depress it enough to where it wouldn't latch. I really didn't want to rerun the SATA cables (or even mess with any of the cables), and decided on trying to flatten the release latch so that it hopefully wouldn't do it again. After some careful squeezing with a pair of pliers, I got it flattened enough to where it stayed latched with the other SATA cable plugged in above it. The only thing is that it seemed like the release latch was dangerously close to the edge of the moulding that keeps it down.

Before and after.

While it wasn't directly related to the project, it was caused by this project. Anyway, the day after I crimped new connectors to the switch harnesses with the new crimp tool (Engineer Inc. PA-20), noticing that some of the previous contacts came off a bit too easily.

Just an after image because I was kinda in a hurry.

I had also really awkwardly used my new heatgun to shrink the new tubing, but it turned out well enough. The boards were supposed to arrive that day as well and I spent time desoldering all the components from the PCB, and once I was done with that, I just killed time in my room as I checked the tracking number.

Unfortunately, the boards never showed up, and for whatever reason, it took the package seven hours to get to the local post office from the main one which probably isn't more than an hour away. I was irate that the rest of my Saturday went to waste, but after getting home on Monday from work, I got the boards and quickly started on finishing the project.

The usual views. Yay 3.1! (Maybe "Yay!"...)

I first set the jacks into the PCB and checked the hole spacing to ensure myself that this wasn't going to all go horribly wrong at the last moment again, and i was definitely reassured.

Blast that bloody window!

I quickly began soldering the components back to the board, starting with the resistor, and I almost soldered the Molex header before the relays but I caught myself before I let too much solder flow.

Progress.

Being paranoid doesn't hurt sometimes, right?

With just one leg of the jack soldered, I tried a few things to try to keep the jacks aligned before deciding on just utilising "brute force". Once it was soldered, it looked fairly nice in the panel.

Still have a bit more to go.

Since there was the leftover PCB from when they were connected to the other PCBs in the panel at the board house, I decided to see if I could file it away enough so that it wouldn't interfere with the panel later on, and I was surprised with how easy it was - I just wished I thought about it before soldering the jacks on.

I think you can tell?

With how wide the outermost diameter of the shoulder washer is, I knew I had to cut them down so that they wouldn't overlap, and while I should've done it Saturday, I was a bit too frustrated with the post to do so. As I began cutting the first, I decided on a pattern, where the middle would be uncut, and the others would "D" outward from it.

The pattern as I was cutting the shoulder washers. The cuts shoulder washer, with the shoulder up.

Luckily it didn't take too long, and I awkwardly tightened the nuts with a pair of needlenose pliers (after failing to use a slotted screwdriver on one side of the nut). I tried to get the slots to line up, but eventually gave up.

Finger-tightened and plier-tightened.

Now that the board is assembled, it was time to install it. I first chose the slot directly above the Sound Blaster card, but found that I'd have no space at all for the plugs, so I moved it to the one above that. I also had a tight spacing issue with the 1394 front header plug, and so after I moved it up, that was no longer an issue.

Harnesses connected to the board, switchboard in the originally-intended location, switchboard in the revised location.

Next was to connect all the right-angle stereo plugs into their proper spots and to test out the sound. I ended up switching the spots for orange and black because of the Logitech's X540 cable harness. It obviously doesn't matter as long as the flanking cables are of the same "colour".

Views of the semi-organised "mess".

Manjaro passed the surround sound test, while I had a weird issue with Windows - the surround speakers were putting sound out through the center and sub while the centre and sub was coming through front speakers (or something like that). I checked that everything was correctly plugged in and such, and eventually looked up the manual to see that I had shifted plugs to the right by one jack when I had put Melty back under the "desk". After fixing the cables, Windows passed the surround sound test.

The semi-organised "mess", revised.

I think I explained that the LEDs in the switches would light for the soundcard not in use. So when the motherboard's soundcard is "active", the switch to change to the Sound Blaster card would be the lit LED, and vice versa. Probably a bit easier to see...

Sound Blaster card "active", motherboard soundcard "active".

I was done, I was satisfied, and I cleaned up whatever I needed to clean up and take care of other things before heading to bed.

Recently I found an Iwiss ratcheting crimper that works with JST connectors, which I think are very similar to the tiny Hirose connectors I use, and I had saved it in my wishlist while my compatibility question went unanswered on Amazon. Eventually I went ahead and ordered it to test it out for myself, since it seemed like I wasn't ever going to get an answer. I received it last week and first utilised it on the breadboard power cable, confirming my theory.

Today, I decided to redo the connectors (third time's a charm, eh?) since I was pulling out the bracket out to remount the card reader with washers, and ended up redoing 6 of the 8 connectors (two of them were crimped too well with the Engineer Inc. crimper and didn't want to come off at all). It was obviously a lot less awkward to redo the heatshrink now that the cable ends aren't inside Melty.

Four connectors after crimping new connectors, two connectors after crimping the new connectors (red and white), and completed ends. Also, dry skin is dry.

I also poked around and had a suspicion that some sheet metal screws from work (it comes with one of the parts that is purchased, but doesn't get used) was similar in diameter and thread to the ones that held the bracket to the case, and after confirming my suspicions, I decided to utilise them to secure the bracket to the case even further, although the screws are much longer than the ones that came with the bracket.

Longscrew is long (but doesn't encounter anything).

After getting the bracket back in Melty, I re-ran the cables and did a bit of cable management, closing her up once I was done (though I forgot to reconnect the USB 3.0 front panel to the header).

Inside views. I tied the cables from the card reader and a SATA power cable to the edge of the 3.5" drive bay (a bit hard to see minus the red cable ties).

I also meant to take a picture earlier of the cable management of the top fan cable, where I removed the pins from the housing and threaded it through the hole of the cable tie-down loop of the motherboard tray to get a much neater look.

Black (or red) heatshrink would make it look even better, but I realised too late. C'est la vie.

The relays are actually audible this time, since the board is attached to the panel via the audio jack threads. It's not a huge deal, since it's just one simple "click", though I doubt there's an easy way to silence the relays anyway.

The only way to improve this project is to have it auto-switch, but I think that requires parts I'm not familiar to using.

I think the main thing I learned with this project is to not assume. I only really took a ruler and thought that the hole spacing (centre to centre) is about 1mm without taking my calipers and measuring the actual spacing between the holes (by edge) and the diameter of the hole itself. Had I known I was going to screw up ahead of time, I probably would've made a proper 4-layer board with the sound traces in the inner layers, so that the ground planes would properly shield them from EMI. I suppose I could improve it that way, but I've already spent enough money on this project.

Eventually I'll work on the Raspberry Pi clock project, but it's just a side project and not a main project like this or the solder station. For now, I'll be able to focus on story-writing since I have about 3-4 stories I want to work on (one of them just needs another pass of proofreading), and sometimes I don't want to pull myself away from it to do other things.

Anyway, ciao for now!