Planning a Semi-Sealed Night Light Part 2

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am covering the repair of my laptop with what I believed (until just minutes ago) was the only full sized SD card reader in the house. Let’s get started.

My overall project will rely on the 3D printer, but the only installation of my printer’s slicer is on my laptop. I’ve had this machine for almost a decade. Even though it’s an old machine, it can still barely keep up with my relatively relaxed demands from it. The slicer is still well within its capabilities relative to my patience.

A few weeks ago, I want to say a month or so, I was setting my laptop up for streaming our church’s service, but it didn’t like its power chord all of a sudden, so I set Blinky Pie (My Raspberry Pi computer) on the case. Meanwhile, after testing and replacing the old power chord, we compared the power port to known good ones, and a central post was missing.

My father and I ordered the part from an official source, and finally got around to changing it out. Note for future operations: When the part you’re replacing is at the bottom of a tightly packed pile of electronics, check the fit with any external connectors before installation. We were okay this time.

The repair took a while. My father did most of the work while I navigated the service manual and kept most of the parts straight as they came off. While it was open, we took the opportunity to extract this impressively rectangular dust bunny from the fan as well as a few rattling pieces, mostly broken bits of plastic, but there was a mysterious screw. During reassembly, I found that three of the screw guides/spacers were broken off from the case. I removed the speaker assemblies from around their spots, and found patterns on the sides to tell which was which. We super glued them in place and finished reassembling. I think at least one of the super glue jobs didn’t hold

We plugged it back in, and… got the same error that started the mess. The brand new power chord isn’t recognized. Some research online suggested it may be the motherboard going bad. That one hurts. I’ve had this machine for a large chunk of my life now, and I still had more plans for it. There may still be a little hope. The internal chord for the replacement power port was a bit longer than the original, so we might have ended up with an imitation or one meant for a different model. Otherwise, it might be a BIOS problem. Time may yet tell.

Final Question: What was the most intense repair you’ve taken part in?

Planning a Semi-Sealed Night Light Part 1

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I’m starting a new project where I install some electronics while a project is still printing. Let’s get started!

This will be a much larger print than I’ve ever done before. I know that already. I’ll be laying out the pieces of the project and ordering them as I write, just to play with the writing style.

Different parts include: Blender modeling, Laptop repair, White filament, and Assembling a circuit. If I think of more, I’ll insert them where appropriate.

Project Concept: the final product will be a gift for a friend I’ve known for a long time. It will be roughly cube shaped light printed from white PLA with relief pictures of either Angels or Cats on the sides. For extra style and practicality, I want the top sculpted to look sort of like a curved roof. A long lasting light bulb will illuminate the whole thing from the inside from atop a custom circuit board, but anything inside won’t be accessible after the print is finished.

Laptop Repair: the other week, my laptop refused to accept my power chord. It looked like a bent power pin, but it was a large piece of plastic from the port missing. That will easily take up a post when the part comes in and I cover its repair.

White Filament: I have two colors of plastic right now, black and red, neither of which would look good for a light. The plastic needs to let light through, but also go with pretty much anything.

Assembling a Circuit: this is a topic that could easily take two or three weeks and will challenge and grow my abilities the most. Simply put, I have no idea what I’m doing here, except that I need it to move power from the power chord to the light bulb, and maybe some colored LED’s around the outside. I’ll want to thoroughly test it before final installation.

Blender Modeling: this one will happen in tandem with the previous one. I’ll need to establish a maximum size for the circuit board based on how big I can make the case with the printer. But I’ll need the final measurements of the final board before I start the final print. Unless I want to toy around with an induction based power chord, I’ll need a place to plug in a power chord. It might also help if I was able to screw down the board itself.

So far, I have a fairly good idea for the overall shape modeled in Blender; I don’t think I have a good mesh yet, the boolean operator didn’t exactly like two half-cylinders intersecting like I had them doing.

Final Question: How have you aimed for something out of reach, but not so far as to (hopefully) be unobtainable?

An Experiment Rerun

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am rerunning the experiment from a few months ago to see if my Raspberry Pi is likely to melt through its PLA casing. Let’s get started!

Last time, my apparatus failed miserably. The painter’s tape holding the thermal probe in place slipped just enough to let the probe get away from the point it was supposed to be measuring. This time, I used Scotch tape, and it held. Another improvement was a custom program that ran all the CPU’s cores at 100%, compliments of the workshop I’ve been going to. I recorded temperatures to the nearest tenth of a degree instead of rounding to the nearest whole.

Results for today’s experiment. All measurements are in Fahrenheit.

I ran the experiment for an hour, taking measurements on a white envelope on my desk, a chip on the upward facing bottom of the Pi, and the probe measuring the target spot on the case. Measurements were taken while it was off, after the Pi had been running long enough to level off the critical spot’s temperature, and every five minutes after the test started, with extra data points at 1, 2, and 3 minutes.

I changed procedure at the 15 minute measurement, as the temperature from the chip was highly unstable, likely due to temporarily improved ventilation by removing the case’s head. After dropping this measurement, I noticed the probe temperature climb from slightly faster before stabilizing to within a degree of 102 F for the second half hour of the test, well below the glassing temperature of PLA.

Conclusion: While this case should be fine with whatever load I put on it, PLA is not the material to be making computer cases out of.

Final Question: Have you ever changed an experiment mid-procedure because you suspected your measurements were affecting your results?

A Series of Dead Ends

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I don’t have much, but I’ll try to put something down. Let’s get started!

I went to the workshop again this week with a list of things I wanted to figure out how to do, starting with getting TightVNC to switch users. Nope. TightVNC servers are tied to a single log-in session. Without good communication, that piece of information took between thirty and sixty minutes to figure out. We did get a copy of the heater program working the Pi at 100%. Before I re-run the temperature experiment and risk damaging the case, I have another side project I want to try figuring out.

I have a friend I haven’t seen in a while and he lives in another State. I want to show off my ghost case (Now pictured), but I want to call on the Pi and hold up a mirror so he can see it with its own ‘eye.’

My first thought was to just download Discord and call it good. Oops. The Raspberry Pi may be 64 bits, and Discord want to run on 64 bits, but Raspbian doesn’t exist on 64 bits. I found a decent-looking forum post [LINK] that discusses 64 bit computation on the Pi 3 series. Long story short: 32 bit Pi computing has inertia. They don’t make 64 bit Raspbian because it would cost more utility than the few who seek it out would gain from it; it simply isn’t worth it for an official, 64 bit Raspbian to exist.

Jumping back in time to before I found the article, and I had just given up in the short term, I looked around to find that there are operating systems that can run on the Pi that use all 64 bits, but several comments seem to describe the wanting nature of either the setup process or trying to squeeze any additional performance. My thought is that such operating systems are often not optimized specifically for the Pi and take up what benefit they otherwise would have had with additional overhead. The extra bits are there if you need them and know how to use them.

At this point, a Discord client is looking like a no-go, but I did try to get a call set up in the browser. I haven’t gotten it to work yet, as I need to figure out how to get my Pi Camera and Blue Yeti to play nicely with the Discord site in the Chromium browser. It’s just something with the permissions, I hope. I remember seeing something about the Yeti not giving Linux a single thought in its advertising, but I think I remember seeing it show up in the Discord web page.

Final Question: Does anyone actually know if the Raspberry Pi will melt through a PLA case?

Review and planning session

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am laying out my plans for the near future. Let’s get started!

I’m still figuring out the new setup with Derpy. The VNC client I set up on my main desktop isn’t sending keyboard shortcuts when remoting into Derpy, but my laptop does and I cannot find the setting to change it. It also seemed to prefer opening up programs for a local login (if present) if the remote server requested anything be open. I upgraded it to Ubuntu 18.04.1 LTS after trying to get some tech support over Discord.

In my last post, I believe I said I was now using GNOME 3. That was wrong. I’m on the Xfce desktop environment and I couldn’t tell the difference, especially while trying to elicit help. I’m willing to work with this desktop environment, as I hear it is supposed to be pretty stable, and it’s the only one I have to work with at the moment. Yes, I don’t have a way to switch desktop environments remotely. I tried logging out remotely, and the VNC session became unusable with that complex black and white “gray” pattern, replacing the desktop picture as I dragged lingering windows around. A reboot fixed the symptoms, but I still want to see about getting the root cause addressed sometime.

I have a few things I want to finish before going on with programming the Pi to detect and deter cats. Mostly the more intermediate Linux literacy skills, like getting WINE to run things reliably, or forcing a piece of hardware to work when it shouldn’t.

During my miscellaneous research this week, I found Rasbian is only a 32 bit operating system and the Raspberry Pi 3 family is all 64 bit based. I would like to explore benefits and drawbacks to finding a lightweight version of Linux to run on the Pi and running that for my cat program instead of just programming it for the board’s default OS.

Final Question: It’s hard to know what version of an otherwise identical product to go with, especially if you’ve never needed it before, especially software. I find a good word from someone I know goes a long way. How do you decide what version to use?


How I Prefer to Deal with Griefers

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am using some kind of new WordPress backend interface to tell you a story this week about something that happened on a creative Minecraft server I run. Let’s get Started.

A while back, I did a project where I revitalized an old, boat race minigame from a previous season of the Minecraft server I play on. I set up a private server to test this operation. Later, my family started projects on that server for others to come in visit before they were built for real. Part of the boat race required people to have OP privileges to work, and not everyone knew about the work on the race. Those that knew ended up being those with OP privileges.

Last week, I heard a report of confused member wondering where the warp points to the different projects went. I logged in and found tell tale signs of explosions around spawn. The pad with all the warps was gone, its command blocks smashed.

I found a name and what looked like a method of destruction. This person had gotten an advancement related to spawning the Wither Boss, a very destructive enemy in the game, and thought it didn’t quite look like a Wither Boss’s direction of destruction, it was close enough to get me to pursue that line of investigation. 

My mother was my primary ally this time. Over the course of a day, we questioned the suspect and assembled a story out of they told us. Apparently, a younger sibling had logged in from school with her account, having mysteriously gotten the IP from somewhere, spawned the wither, [smashed the command blocks], and left. Later, they logged back in and quickly left, fearing they were being framed.

The story didn’t seem quite in line with what the command line was saying, but with only a mouse on Derpy Chips, the computer the creative server is hosted on, things were going a bit painfully slow. I found the IP the griefer was using, and an IP associated with a legitimate access where they had a conversation in chat. The IP’s matched. I know a little about how IP addresses work, but I’m no guru with them. What it looked like to me was that I was getting the IPv4 of the ISP (Internet Service Provider) for the city they were in, and that that was a dead end for investigation for the time.

No matter the story, I was already thinking of how to fix the mess. I knew I had several, old backups and I could just use some of the files from good files instead of the griefed ones. I set Derpy up for work, but found it impossible to easily move the needed files from the latest backup to a copy of the current world.

I thought it would be a good time to try working on my next blog post (today’s), where I wanted to set something up so I didn’t need to ever switch screens and controls around again. Long story short, I tried to plug a different keyboard in from another computer, and it worked. I moved the appropriate files to the copy and had someone look at spawn… and it was the old, bland spawn. I didn’t have a copy of the nice spawn that got ruined. Oh well.

Meanwhile, my mother was still suspicious of the prime user of the grief the account that did the deed. I went chatting with them late at night, getting their story out of them in text before eventually pointing out that it didn’t match up with what I remembered of the logs. I went to sleep, and in the morning, I found a full confession. It was TNT, the wither skull was just meant to look cool, and the self-given command block I had originally assumed had been used to kill the non-existent Wither Boss was a red-herring. They were the guilty party, and they were truly sorry.

In that moment, I felt sort of like how a villain might describe the rush they get when they have their foe begging them for mercy but are still going in for the kill, but my only I thought was to forgive the party who had wronged us. It took me a while to word my response, and my mother had actually gotten back to them before I could respond, but we all were leaning toward forgiving them. OP privileges were revoked, of course, but while flying over the destruction, I was thinking to myself, ‘That would make a really nice lake if it were properly decorated.’ We asked them to repair the damage as a friend.

I was most surprised at their reaction to being offered forgiveness. They were expecting us to get mad, toss around bad names, badmouth them, ban them, and hate them forever “to put it nicely.” I honestly cannot relate.

We asked for a chance to share God on this server, and we can hope that they go and do likewise.

“‘If your brother or sister sins against you, rebuke them; and if they repent, forgive them.'” (Luke 17:3 NIV)

Final Question: Have you ever been forgiven of something, or been a position to forgive someone seeking forgiveness?

Stress Testing PLA as a Raspberry Pi Case Material

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am running a looping Hello World program on my Raspberry Pi for a while to see if my work for the last few weeks needs to be redone in ABS plastic. Let’s get Started!

I’m going with the hypothesis that while the Pi may run a bit warm for PLA plastic, with the heat syncs, and ventilation, I should be okay.

My procedure will involve using an infrared temperature sensor I borrowed from the workshop I joined a couple months ago. After messing with it for a while, I figured out how to use the temperature probe that came with it. I’ve taped the probe in the space I’m most concerned about overheating as I don’t have a line of sight view of the place.

Each data point I take will track the ambient temperature of a consistent point nearby, the temperature of the probe, the CPU speed, and some points will take the temperature of a chip on the inverted Pi’s exposed underside, but only when data points are coming in after 5 minutes or more.

***

I’ve started collecting data. The probe wire is notoriously difficult to keep in place. I took data points while it was off and freshly booted. Nothing much changed temperature wise except the chip getting a little warmer. I’ll include a screenshot of my results later.

***

It’s part way through data collection. I may have skewed the results of collecting the data on the chip on the top side by measuring at a different angle. Ambient temperatures are fairly steady but the probe location below the heat syncs is slowly climbing. I just took another measurement, and the possibly skewed one doesn’t seem like I’ll need to throw it out after all. I was hoping it was my readings and not a temperature spike. I’m also concerned that the probe may be slipping, especially if it’s getting closer to the heatsink.

***

The probe was slipping! Its readout was growing steadily as the tape holding it in place gave way. My data at T=40 minutes and on will have it correctly positioned.

***

***

Estimates of the low end for PLA softening are around 60 degrees C or 140 F. In conclusion: While I believe my data has a large margin of error, I do not believe it is so great as to void my conclusion that it is safe for my case to operate my Pi under these conditions.

The Pi only ever reached 33% CPU usage, I believe it was throttled by the task of writing to a command line. If it were to run hotter, the plastic might still be in danger. I will need to redo this test when I’m running image analysis on it.

Final Question: How else can I improve my tests?

 

A New Tool Part 13

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I’ve finally completed the construction of my New Tool!

I believe it’s only appropriate that I write this post on the computer in question, a little Pac-Man themed Raspberry Pi system I’ve named Blinky Pie.

The work this week was actually fairly simple. I stopped by a local hardware store with the Pi and the case to pick up two screws, and the guy who helped me was very knowledgeable. He helped me choose screws that were big enough to hold the board, but not so big as to crack the printed plastic.

Before I did my final assembly, I did a dry run where I taped the camera in place across the top of the dome and down the other side, and it worked pretty well, so well, I only had to add a final piece to keep the camera secured.

I took the camera out to finally install the two heat sinks that came with my Raspberry Pi starter kit, a task my father was happy to help with. After that, I installed its ribbon cable around the back of the board where I could install it with the screws I picked up earlier after making sure the camera was installed correctly. Of note, I have been having a lower rate of failure when installing that thing lately.

While celebrating the final completion of the base hardware for my tool, I ended up exploring some settings on the GUI, specifically the task bar, or as Windows would call it, the Start bar. I found a setting to customise the color, and about a setting for about everything you could think of and double it. The term is called “decision fatigue.” There are so many settings, you can spend, and have to spend an hour or two to get everything looking OCD compliant. One glitch preventing using the “icons only” setting from save space has a workaround of moving the task bar to a side and back again, but that throws a bunch of other settings into chaos, mainly the height of the task bar, and guess who doesn’t have a “restore to defaults” button!

I’ve run multiple tests with the Pi idling in the case before its final installation. I’m pretty confident the case won’t melt. It’s well ventilated by the heat-sinkable chips. I even ran the dry assembly for a few hours, and the plastic around the stock board with out heat sinks was only warm.

Final Question: Besides feline repellent, what other applications can you think of for a Raspberry Pi with a camera?

Headphone Repair?

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am trying to fix a pair of headphones that popped a joint while I was off on vacation this week. Let’s get started!

I’ve had this set of headphones for a while now, and I’m not always the most careful with my technology. I often leave them on top of my cluttered desk or computer tower, and the household cats often pilgrimage to the window behind my desk. Be it from my cat or my klutz, the headphones often would wind up falling to the floor, and I would count my blessing when they still worked each time they tumbled.

Typically, I’ve had headphones fail at the micro-USB connection from the wire to the headset. This time, I stuffed them in a backpack along with a couple other laptops and a keyboard. Sometime between home and our second hotel, one of the sides had popped out, likely when a dog crate shifted into the backpack momentarily. I tried to push the piece back together, but I was afraid of damaging it, partly because we’d had the opposite problem happen to one of our dogs’ Gentle Leaders (a training tool worn on the dog’s head).

With the lack of enough progress on the Pi case I’ve spent months slugging on about, I noted the lack of broken-looking individual parts on my headphones and decided it wouldn’t hurt to disassemble the hypermobile joint and put the whole thing back together correctly.

I started by removing the four… three of the screws holding what was left of the wayward side together. The forth one was a little stubborn, but it eventually came out. The piece itself had a little more resistance, so my father and I coaxed it out gently.

Exploring the inside was a little disappointing. The first sign this wouldn’t be a successful mission was the tweaked, plastic fingers meant to hold onto a grooved peg (helpful for) earpiece rotation. Additional bad news came when I spotted an actual crack in one of the brackets.

For the purposes of the blog, I decided to pull the other piece off for comparison. Remember all those drops? The teeth on the “good” removed piece were well on their way to deforming in the exact same way. The backpack getting crushed must have affected only the one side and was either enough to finish the job or do it from scratch.

Either way, I won’t be able to repair them as I’d hoped. I wouldn’t trust my 3D printer with something so delicate, and even if I did, I don’t have a pattern or a way to scan the “good” piece (so it can be mirrored). The plan is to screw the pieces back where they go and either cache in on a warranty or save them for parts.

Final Question: Have you ever had to back out of a repair project when its apparent difficulty level spiked?

 

A Spot of Network Maintenance

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am scratching around for something to talk about and I’ve come up with reviewing a home network crash this week. Let’s get started.

Years ago, I was staying in the dorm at my university as a Freshman. The walls were concrete, so they didn’t have the campus WiFi installed. If you wanted your own WiFi, there was a hard rule: “Absolutely no routers” because it messes with the network. Instead they had these wireless access available from IS (Information Services, the local version of IT). Each room had two Ethernet ports (and two disconnected phone connections thrown in for free), and even though I was alone in the room, I had my desktop, laptop, and now an access point. Hard wire is much better than the unreliable WiFi, so I ended up picking up this Ethernet switch.

An Ethernet switch is a step above an Ethernet hub, which was also allowed. While a hub just repeats each signal it gets to all the other connections, and the wrong connections ignore them, a switch directs signals to where they actually need to go. I ended up with an eight way switch.

My switch served for the next few years and eventually got integrated into my family’s home network system, where it’s been serving with all but one connection for a while. This week, the Internet cut out on us, all devices at once. My father was the one who actually talked to tech support, but after they told him his router was bad, he did some additional diagnostics, which pointed to my switch having failed.

My mother and I went to buy the replacement the next morning, and I was a bit perplexed when I opened the box. The old one was simple: plug and play. This new one comes with a CD, and an instruction guide for setup that doesn’t even work straight away with Linux. At this point, I’m getting conflicting impressions: Linux is king in the server world and prominent with people who are into computers, but they only seem interested in catering to Windows users.

I ended up ignoring the fancy setup for now and tried plug and play. It works. I cannot imagine why they would not list that as an option. It would have been a bit less frustrating if they had just said so right away and stated their extra software as “optional, for enhanced performance” or something like that.

Update: As I was finishing, the Internet dropped out again. After it’s stable again, I may want to take another look at my switch to see if it was working all along. In the meantime, a router reboot fixed it for now.

Final Question: What was the last piece of computer hardware you wore out?