and one button to rule them all

The project from yesterday and today is something called a “dash button”, an IFTTT or an IoT button. Push the button and some activity gets invoked (usually, remotely). Amazon’s take on this is for you to be a consumer, press the button and something gets ordered.

dash

My own take on this is to add a big red button (BRB) as a remote panic switch for the 3D printer. Press it, magic happens and the print job is paused. It’s useful when something bad starts to happen and you need to make it stop quickly.

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There’s not a lot of room inside the printed plastic for this. Whatever electronics it uses, it will need to be small enough to be self-contained.

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I’m currently accomplishing this with a nifty Adafruit Huzzah ESP8266 board, a charging module and a 3.7V battery. I’m using the Arduino software to “flash” (upload) code to the tiny processor as well as a full directory of files to support the webserver which runs when it’s in configuration mode.

By strapping a pair of header pin connections and pushing the reset button, it now boots up in wi-fi hotspot mode and serves up a configuration website. Submitting to the form then re-configures the device and resets it again.

Booting up now in the standard mode, it then connects to the local wi-fi and attempts to then connect to the URL that you’ve given it. Once it does all this (perhaps ten seconds’  worth of activity), it promptly goes to sleep. Press the BRB again, it wakes up and goes through its routine again.

If you think about it, it’s now a reconfigurable dash button and much more useful than those one-trick-ponies as provided by Amazon.

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adafruit 2.8″ capacitive tft screen

Today’s review is on the small TFT touchscreen for the Raspberry Pi computer. At $45, it’s not the cheapest screen you could add onto a single-board computer but the capacitive touchscreen and the four accompanying tactile pushbuttons along the side make it worth the extra money, especially if you’re adding it to a 3D printer for the sake of control.

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TFT

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Installation

As usual, the Adafruit documentation was more than adequate to get this done. They provide an installation script which makes the process easy.

Observations

The touchscreen works wonderfully, much better than the typical/cheaper resistive TFT that we’re most familiar with.

I’ll need to determine which GPIO pins those four pushbuttons go to. It will be nice to use those in some sort of interface.

I reviewed both the OctoPrint-TFT and TouchUI interfaces for OctoPrint on this. I’m not convinced that either are a perfect fit, given the size of the screen. Both required the Desktop to be installed on Raspbian. In the case of TouchUI, it required the use of a local browser on the Pi (Chromium) but I was able to get this to go into the full screen mode.

Other than as a control interface for a 3D printer, I’m not quite sure what projects would be a good fit for this. The timelapse rail kit would be good for this setup, perhaps. It’s a little bulky for a cryptocurrency cold wallet. It would probably make a good streaming music player, given the positioning of those buttons.

Adafruit makes some very attractive enclosures for this, unfortunately they’re out of stock at the moment.

  • Size: 2.8″ (board matches form factor of Raspberry Pi 3B)
  • Screen dimensions: 50mm x 69mm
  • PCB dimensions: 56mm x 85mm
  • Brand: Adafruit
  • Model: 2423
  • Name: PiTFT Plus 320×240 2.8″ TFT + Capacitive Touchscreen
  • Cost: $45
  • Resolution: 320×240
  • Touchscreen type: capacitive
  • Feature: extra 40-pin header underneath board
  • Feature: four tactile pushbuttons

old-fashioned milk bottles

Once upon a time, you’d get milk delivered in the morning in glass bottles. Okay, honestly, it was other people who got that but I do know this from watching old movies.

milkman

Now that I’m old enough to go shopping myself, I have a fondness for buying my milk in bottles like this. For most people, I’d guess, the thought of adding an extra $2 for the glass rubs them the wrong way. For me, I see it as an excellent way of picking up a great deal. It would cost about $10.84 for that same glass two-quart container from Amazon.

Re-use, recycle, re-invent

So what would I do with the extra bottle? Almost anything that can fit through the top is a good candidate but food is what I primarily store in mine. I have at least 30 bottles storing dry goods, two storing refrigerated drinks and perhaps eight storing filtered water.

When I make waffles, I usually mix up several batches of the batter and that will go into the pint-sized glass bottle. Turbinado sugar also goes into the pint-sized version, making it easy to spoon straight out from there.

I purchase the Mueller’s pot-sized spaghetti which fits nicely into the quart-sized bottles. Most flours as packaged by Bob’s Red Mill will exactly fill the quart-sized version. Potato flakes? Check. Granola? Check.

I have rows of beans and lentils, pastas of all shapes, flours, starches, coconut flakes and almond slices. There’s trailmix in one. I have semolina, masa, corn meal, oatmeal, Scottish oats and Creme of Wheat.

In the refrigerator today I just added two quarts of iced tea and a quart of iced coffee. Three visits to a local coffee shop would probably set me back $12 for three drinks and I’ve just stored away the same amount for a fraction of that cost.

Perhaps the best benefit of storing most of your pantry in glass is that you no longer have to deal with pests. This is the first time in my life that I have literally zero bugs trying to eat my food.

Enter the 3D printer

The tie-in, then, to the 3D printer involves me designing a replacement funnel using Autodesk Fusion 360 for the purchased funnel I’ve used up until now. Hopefully it turns out, it’s about as big as my printer could do.

The previous funnel was okay but it wasn’t a great fit for the bottle. Big items like granola would constantly get stuck in the too-small funnel neck. This one should fit perfectly.

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Food safety and plastic

Some of you may then caution about the use of printed plastic in conjunction with food. I’m sure the PLA filament (which is made of a polymer of corn starch) is actually closer to be food-safe than the funnel which I’d purchased from a car parts store earlier.

Some of the typical concerns with food versus printed plastic is that the small grooves in the plastic allow for bacteria to grow. Okay, but this is the same for most of the plastic utensils which we routinely include in our kitchen, right?

Another concern is regarding the existence of lead in some of the nozzles used. Yes, but that must be so minuscule as to be outside of the realm of concern. In response, I could site the many harsh chemicals used in the processing of naturally-green soybeans to create an unnaturally-white soy milk product, for example.

For dry goods, the PLA funnel should be a non-issue. With reasonable cleaning I think that it will do fine with liquids as well as long as I don’t use it to funnel boiling water, for example.

what’s up, dox?

Earlier yesterday, I visited the Amazon Bookstore and saw one of these DOX things.

DOX

So, of course I thought, “I can do something like that”. Returning home, I immediately designed a base for the Echo Dot and sent it to the printer.

I’d initially decided to use the new GP3D FLEX filament I’d bought earlier but it’s so amazingly flexible that it adds challenges to the process:  1) it really adheres to the print bed so well that it refuses to pop off from it, it must be peeled off instead; 2) when the bowden pulls on the main filament roll, the material is stretchy rather than delivering like you’d expect; 3) the diameter of the filament is too inconsistent and gets caught up in the PTFE tubing.

That said, I turned back to my standard PLA filament and proceeded. The part finished last evening and it fits perfectly. It wants some light sanding where the supports were but it’s very functional, directing the downward-facing speaker toward the consumer and lifting it from the table by 25mm.

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the braille project

Yesterday, I designed a Node-based program to generate a 3D mesh file programmatically from the input text to create a braille message.

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The concept is easy enough to grasp. Braille is a simple combination of raised dots. If we can know that combination, then it should be easy enough to design a 3D CAD object which uses tiny spheres to render the scene.

But I didn’t want to laboriously design this in Autodesk Fusion 360 and I’m sure few people would. Everything has to be precisely placed and that’s just too much manual work. Even if you did, it’s not very easy to maintain. If you did catch an omission, just think of all the work you’d have to do to move things around! I’m relatively certain that this is currently how people create braille-based printouts as seen on an ATM machine, for example.

3d-braille

So yesterday, I designed and created a program for doing this. Generating the STL file was then painless and took less than a second. Printing it then took five hours so I got to see it as a finished part this morning.

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saving the day for thirsty students

The place where I work has a refrigerator in the kitchen. The water dispenser in the door is wonky and before yesterday, it wouldn’t turn off automatically. Perhaps at one time, there was a spring which makes that tab want to stay forward but it was broken a long time ago. Most new students were initiated to this when they accidentally spilled at least a cup of water on the floor.

dispenser

So of course, I decided to fix it using the 3D printer at work. This was made more difficult since I hadn’t brought a digital caliper with me nor a ruler. I used earlier-printed parts to measure the tab (since I did know their dimensions) and then went to work.

Autodesk Fusion 360

The first step was to design the part in a CAD program. Imagine this then fitting over the tab with the extended “spring” resting against the back panel of the refrigerator. I had to plan in the amount of force required as well as that necessary to keep the part from sliding off as well as the internal play required to fit this over the tab.

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FlashPrint

Next, it was necessary to “slice” the model file into a toolpath file for the printer, a set of instructions which it needs to create the part. I used PLA filament since it’s easy to work with and decided to orient the part sideways on the bed so that the spring part wouldn’t be an overhang (which sometimes causes problems). This meant that the printer at the end would need to bridge the two walls it had created with a 5mm gap between them.

Flashforge Creator Pro

I transferred the toolpath file to the printer and got it going, noting the time. I made some guesstimates about when it would finish and it was done about five minutes after my shift completed. It bridged that 5mm gap without a problem, finishing the “roof” at the top.

While it was still hot, I put the part in place on the refrigerator and it fit, working perfectly and solving the problem. Use a glass to push against the tab, water dispenses. Release and the water stops. No more huge spills on the floor as a result.

Refrigerator

logistics for the black pearl lcd theme

I decided to add more to the earlier Black Pearl Conky theme for my 3D printer’s TFT screen. It turned out to be a lot easier to do since I’d just finished a new module for OctoPrint.

octo-client:  A node-based module for directly talking to OctoPrint to gather raw information.

octo-conky:  A Conky script for returning that information in a pleasing way.

The new information is there after the “Black Pearl v1.0.1” line where it pulls the version and temperature from the printer.

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beehive varroa barrier

This is a second post of two, hoping to address the needs of beekeepers in preventing the Varroa mite from entering the beehive’s brood chamber, devastating the pupae inside.

bee-with-varroa-mite

The mite jumps onto the adult bee’s back while it’s foraging for pollen and then rides back to the hive. Once inside, it lurks near the brood cells after the queen has laid a round of pupae. While those cells are being capped off by the bees, the mite jumps into one of the cells and feeds off the young.

This design involves a means of brushing off the mites as the bee enters the hive. Mylar door gates differentiate entrances from exits; the longer entrances incorporate the brushes which will remove the mites which fall through a mesh into a tray of oxalic acid where they may be counted.

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save the bees, save ourselves

Bee colony numbers have been in decline over the last 70 years. I’d suggest that coverage maps like this are behind one of the reasons.

verizon

Now imagine that you’re a bee and that those signals from the cellphone towers disrupt your ability to navigate. Just like the way that water molecules are targeted to spin in a microwave oven (by carefully tuning the frequency of the radio waves), the tiny magnetic beads in the abdomens of honey bees are the accidental victims in this “marvel” which we call wireless communications. Bees depend upon their own ability to interpret the “feeling” they get when those magnet beads orient themselves in the Earth’s magnetic flux; they are flying compasses if you think about it.

For every particular antenna length, there is a corresponding center frequency upon which it may communicate. The higher the frequency, the smaller the antenna. Conversely, the higher the frequency, the smaller the antenna which will pick up that signal on the receiving end. Today’s race for higher bandwidth and “coverage everywhere” means that wireless communications in the high frequencies used create perfect resonance for those tiny beads and that there’s nowhere for the bees to hide to escape this magnetically-noisy confusion.

History of the cell phone

The real history of the cell phone begins in 1946 when Bell Labs used WWII technology to commercialize wireless telephone in the states. Here is a graph indicating the number of cell phone subscribers from the period beginning in the mid-80s to about 2003.

EstimateCellPhone

Compare this to a graph of the count of bee colonies since 1940, noting that the cell phone was introduced commercially in the year 1946 and would represent the year that cell phone towers started being erected here in the states.

bee-colonies

Where’s the nearest cell tower?

There was a time when you could drive out of the city and immediately be frustrated by a lack of cell phone signal. That’s not so, today. You can drive almost anywhere in the U.S. and get a signal from either your own carrier or someone else’s if you have roaming turned on.

But in our own quest for always staying connected with friends and with work we have really hurt nature this time. We’ve hurt the honey bees’ ability to navigate successfully and they’ve attempted to move away from the disruption, flying further from cities and into zones which are dryer (less irrigated by humans).

Reviewing Verizon’s coverage map above, you realized that there’s nowhere to hide now if you’re a bee. They’ve been pushed to the brink. The further they travel, the less likely there is that there will be water to keep the hive alive and a steady supply of water is crucial for honey production.

What bees mean to us

If you think that bees are only good for creating honey, then think again. Bees are important for our own survival. It is estimated that a third of all food that we eat is pollenated by bees. But then, what about the feed for the chickens and cattle which represents the meat that we eat? The bees pollenate the wheat and the corn as well.

In short: when the bees die off, we’re next.

It’s in our best interest to help the bees as much as we can. We need to learn from our mistakes and to make the tough decisions required for the bees to return in number so that our future will have enough food to eat for our ever-increasing population.

1940-present

Speaking of which, more people means we need more pollination for the food crops and the feed crops, right? There are about three times as many people in the states since 1946 so we’d need the bee colony numbers to increase at the same rate or we’ll be hit by ever-higher food prices, one could suggest. The decreasing bee colony numbers mean that food prices will have inflated more than other consumer items over that same period. If you’re older like myself, you would reasonably agree with me on this one.

Solutions

Lose the towers, change the technology

The best solution would be to radically change our wireless strategy and to ban the use of frequencies which negatively impact honey bees. Given the US$272B which the carriers alone will make in 2018 and the untold amount received in the sales of the phones themselves, it should be impossible to wean these vendors from this business model. Even if you presented the data to them, they wouldn’t believe it. They are simply making too much money from our own daily “need” to take selfies in the Grand Canyon and to instantly upload them to FaceBook or Instagram or similar.

They [the carriers and smartphone manufacturers] are simply making too much money from our own daily “need” to take selfies in the Grand Canyon and to instantly upload them to FaceBook or Instagram or similar.

We’re to blame in this one. A corporation has no soul nor a conscience. We did this to ourselves.

Help the bees in other ways

Perhaps the best thing that we could do is to attempt to help the bees in other ways. This is the approach that I will be taking personally since it’s something that I can hope to accomplish in my lifetime.

Varroa mite

At the moment, hives are under attack from an aggressive mite by the scientific name of Varroa. I am designing prototypes which should hope to help prevent the mite from entering the brood chamber of a typical hive.

A little help from us

Beekeepers typically introduce a foundation sheet of pressed beeswax to make things easier for the bees to start a frame. These sheets may only be shipped from spring to fall since the cold weather will result in frames which have become cracked and brittle. It would be good if beekeepers themselves could create either the foundation sheets themselves or an even better solution.

I’m currently designing 3D-printed molds so that the sheets may be cast in place in the frames in beeswax in the beekeeper’s home (and even during the winter months).

Lowering the cost of beekeeping

Finally, if we as volunteers can introduce free designs into the open source space, beekeepers may take advantage of these designs and to make their own solutions locally. The honey-producing industry includes many vendors who hope to solve the beekeeper’s many problems as they try to remain profitable only these solutions can be quite expensive.

My approach is to provide free solutions and let the beekeepers benefit from my help. By helping them, I’m helping the bees. And when I help the bees, I’m helping myself. I don’t see this as lowering the cost of honey production; I see this as saving the human race, to be honest.

edit gcode externally

I’ve been making some updates to a command line interface (CLI) program lately. I wrote it in the Go language and it’s useful for editing 3D printer gcode files.

A GCODE file is a set of toolpath instructions for both 3D printers and CNC machines.

GcodeEdit

The program is called GcodeEdit and it can so far do the following:

  1. Update the hotend’s temperature, useful for changing the filament material you’d like to use for the part
  2. Show a variety of information from the file, like number of layers and the slicer software which was used to create it, for example
  3. Remove all heat-, fan- and extrusion-related commands so that you can watch the printer go through a “dry run” without wasting any plastic
  4. Repeat the indicated layer but without extruding any plastic, suitable for “ironing” out the last layer and useful during the first couple of layers, for example

I intend to keep adding options to this program and I use it myself, for what it’s worth.

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