Quantum Mechanic

Content tagged Electronics

Fixing our Monoprice Mini Select

posted on 2016-11-26 01:36

A couple months ago, I ordered a Monoprice Mini Select 3D printer. I'd been hearing the buzz for years and at around $200, it seemed like it was finally an offering with good reception that I could feel fairly safe dropping the money on. We printed Millenilm Falcons and a test elephant model that came with it, but then it got relegated to a shelf next to our bed for the last few months while things were stressful and creativity was wanting.

This weekend, we broke it out so we could try to do something fun with it again. We'd never been able to get it to read an SD card, so we controlled it with a laptop that has since retired and it took me two hours of poking at linux serial point things to realize that I'd just updated my kernel and it seemed like something was having trouble mounting serial devices because of it. A reboot later, we were in business.

Unfortunately, that wasn't the end of that, because our printer started behaving strangely; taking lots of pauses for seconds at a time. It was causing beading in the plastic where it stopped, and was seriously lowering the quality of the builds. I'd long known there were firmware updates to be had at the Google Drive for the printer, but without a working SD card, I couldn't do the updates and we were seriously considering having to call customer support.

Thankfully, digging through random boxes bore fruit and I was able to located two more micro SD cards, one of which pleased the printer. Finally, I was able to update it.

Before we updated the firmware, the printer got into a strange state and ran itself to the extremes of the X and Y axes and then tried to go further. When that happened, something happened and the extruder temperature started showing as 0.


0 Celsius is pretty unusual for indoors, even in late Fall in New York, so I figured something was wrong with that sensor. Sure enough, the little wire connected to the thermometer had snapped. Probably, while it wires were stretched to the edge of the print volume.


Luckily, with a quick run for overpriced solder at Radio Shack, I was able to patch it back up and get back to printing.

Finally fixed my phone

posted on 2016-05-15 14:32:00

I like to tinker with things, I own. An important part of deciding to buy any given device is that I can tinker with it, take it apart, install whatever hobby OS on it I like, &c. I'v generally been delighted by my Nexus 4 phone, which I've had for perhaps two and a half years and is my favorite smartphone so far!

Recently, though, Google stopped providing android updates for it (well, I think they'll still security patch Lollipop for a while) when Marshmallow, the sixth food-version, came out. I always like to poke at the new things in life, so I started looking around at my options and saw that there was a Cyanogenmod 13 image for my phone. CM goes by their own numbering system, and 13 corresponds to 6 in the official android versions, which is the latest. I had played with Cyanogenmod a few times over the last few years and so I felt pretty comfortable trusting them with my phone.

On top of trying the new version of android, which seems fine, but hasn't really blown me away with anything new, I also tried unlocking my phone's LTE modem. It seems the n4 shipped with an LTE modem which isn't turned on by default because maybe Google never got it properly tested. Some people got it turned on, though, so it's possible to upgrade your data connection considerably! It was like getting a new phone!

Unfortunately, I also had to seek out and install some Google apps. I'm finding Google increasingly irritating, recently, both in their apps and that they called me for an interview, screwed up the scheduling, then the programming language they were interviewing me about, then let me try again in the right language, and finished up by never responding. Mostly, I would seriously suggest the F-Driod repository of FOSS apps, but I need to install the Google Play Store for my banking app, many things I need for work, and I also make heavy use of the Maps app. So, I bit the bullet and installed Google Play using the Open Gapps project.

For a couple weeks, I tolerated the nightmare of continual modal popups from Google Play Services that informed me that it had stopped. Over and over again, it stopped. In the middle of typing words, it stopped and interrupted me. While trying to get directions, it stopped and never figured out where I was. While trying to find emails, it stopped and got confused. It was really annoying, but it tended to happen in terrible, agonizing bursts, so I could still function. I was busy adopting a dog and being an adult human, so I tolerated it.


I finally sat down and got it fixed.

I tried a billion forum posts that suggested combinations of wiping partitions and dances around blood-spattered stone circles, but that wasn't really useful. I know that most of those things are essentially Skinner boxes, and so I try to avoid them, but desperation makes fools of us all.

I had avoided hitting the 'Report' button on the error dialog, because, on the stock android version, this brings up a wall of legal text about how Google is going to pack up as much data as it wants and ship it off to their servers when you submit the bug report (disclaimer: I never read that and have no idea what it really says, I'm just tired of accepting legal agreements). On cyanogenmod, though, the data will be shipped off to a bunch of friendly hackers (in the best sense of the word) who I don't know, but trust to care more about my privacy than Google, for some reason. I didn't submit the report, but being made by hacker-friendly people, the CM report dialog shows the Java backtrace of the problem. This was the most helpful information I'd gotten so far, and it informed me that the problem was
com.google.android.gms missing android.permission.ACCESS_FINE_LOCATION
But I had given Google Play services that permission!

Eventually, I found an issue that seemed to address it on the Open GApps issue tracker, that contained these commands:

pm grant com.google.android.gms android.permission.ACCESS_FINE_LOCATION
pm grant com.google.android.gms android.permission.ACCESS_COARSE_LOCATION

and that was it. No problems, yet.

I hope that this saves someone all the hours it cost me!


posted on 2014-02-24 02:55:00

Tonight, Sarah and I went with some friends to the local makerspace, KwartzLab, in Kitchener. It was a 'bring your own project' night, though only a few people were there while we were.

There was a pretty impressive array of machinery represented, although, from what I've read of makerspaces, it was probably pretty run of the mill. 3D printer, laser cutter, …. the usual.

One thing that we saw that I've never heard of before was a knitting machine. It was a long line of hooks that the knitted piece hang on. You slide a piece back and forth across and it somehow automatically knits! Apparently, they're also programmable, which is nice. Unfortunately, though, it seems most are programmed with punch cards and the woman operating it claimed that they predated modern computers!

Hopefully, we'll manage to make it back for their Tuesday night open house to work on something. It was nice being around a bunch of people working on projects.

It lives!

posted on 2013-04-06 06:50:15


Today I finished my first foray into home appliance repair! Apparently, the most common point of failure by far for rice cookers is the thermal fuse, which seems to be hidden along some wire inside the cooker.
I found mine in a piece of plastic shielding near the edge of the casing, presumably where the 142 degree tripping temperature would indicate a serious problem and stop the machine from seeing things on fire. Thankfully, a YouTube video had all the answers, and, having located the little device, it was a simple matter to get another from my local radio shack and replace it tonight. Now I'm watching its lights flow again, and it's starting to steam. So, as long as it doesn't catch fire, I think I can count my first repair a success.
It's empowering to be able to fix the machines that work for you. I find myself hoping that something else fails soon so I can learn how to fix something else as well!

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