A near future science fiction short story
“Probability of match, 67.34%.”
The engineer sighed, and shuffled across the room in his tiny apartment to pour another cup of strong, black coffee. He was exhausted. The apartment was overly warm, and a fan in one of the dozens of desktop computers buzzed loudly. He hadn’t been able to track the damn thing down. The place had seen better days — the paint on one wall bubbled near the ceiling from an old leak, and it smelled faintly of mold. He didn’t care.
When he and his wife had first gotten the news, he had channeled his shock into hunting for a solution, and retreated into his own mind. Weeks of frantic reading — trying to understand. Reaching out to a dozen different doctors, hunting for the one who might have just the right experience they needed. Emails to old work contacts he hadn’t spoken to in years, who might know somebody who knew somebody. He was good at solving problems. …
Built around a Pi4, low cost gear motors, and an RPLidar A1
I recently began playing with ROS in simulation, and am really enjoying it. I want a platform that I can use for experiments, particularly learning to configure a physical robot for SLAM and navigation. If you are not familiar with ROS, or have been intimidated by the steep learning curve, you might want to give my introductory article a look first.
I stumbled on the Weddell 2 ROS Robot by user pokpong on Thingiverse, and was very impressed. It was very close to what I was after. I couldn’t source the motors the original device used, so I made a remix of that design that was set up for inexpensive gear motors with encoders. I hope this write-up is useful if you want to do something similar. …
Because huddling around a laptop is no fun at all!
By now, you’ve likely spent a ton of time on Zoom/Teams calls for work, family gatherings, some time with friends, and school. Trying to gather a bunch of folks around a single laptop for dinner or a birthday party is challenging. Holding academic classes on a small screen is not ideal, especially with younger kids. We tried ballet class via video conferencing, with a laptop on a TV tray, and it was… sort of OK. I decided it was time to set up our TV for video conferencing and remote classwork. It’s easy to do, and it doesn’t have to cost very much. …
Use it as a starting point for a bot of your own!
I present here the full code of my first crypto trading bot, in the hopes that it might be useful to others. The bot uses robin_stock, pandas, and ta-lib to make automated trades on RobinHood.
First, let’s make sure we’re clear on something. Cryptocurrency investing is risky. Doing it using a computer program is even riskier. Doing it with code you didn’t write, or don’t fully understand, is a _terrible_ idea. What you do with this code is entirely up to you, and any risks you take are your own. It’s intended to be educational and comes with absolutely no guarantee of anything at all. You could lose all your money. …
There are some subtle gotchas… save yourself some time!
I recently wrote my first cryptocurrency trading bot. I started by playing with historical prices for Bitcoin at ten minute intervals — I loaded them into Python Pandas dataframes and ran some simulations, buying low and selling high. It looked great! The code was simple, too — I figured it wouldn’t take more than a few hours to bolt on some robin_stock functions and go to town. I was wrong. Here’s what I learned as I went — perhaps it will save you some time.
Trading in simulation is simpler than trading in real…
A heat map shows the ebb and flow in different states
This heat map shows the progression of the COVID-19 pandemic in the United States over time. The map is read from left to right, and color coded to show the relative numbers of new cases by state, adjusted for population.
This visualization was inspired by a similar heat map that I saw on a discussion forum thread. I could never locate the source, as it was only a pasted image with no link. The original version was also crafted to make a political point, separating states by predominate party affiliation, which I was not as interested in. …
Sidestep the nasty learning curve and take your bots to the next level
There comes a time in every robot builder’s life when they start thinking about building something... epic. Maybe you’ve built a couple of simple Arduino bots that run around a room and avoid obstacles, or followed a track on the floor. They are terrific fun, and you’ve learned a lot, but you’d like to do something more complex, with some image processing, or network control, or one of those inexpensive LIDAR sensors you’ve seen. Do you have to write all that stuff from the ground up? Where do you even start?
I’d recommend you take the time to learn the basics of ROS. …
Designing and coding an intermediate level hobby robot
Overview
Hobby robotics is a fascinating mix of different skill sets — a bit of electronics, a dash of mechanics, some code. You can go as deep as you want — open source projects make advanced projects like vision or Simultaneous Localization and Mapping (SLAM) easier to implement than ever before. There are even free simulators if you want to play with algorithms and aren’t interested in building hardware. It’s a terrific playground for DIY enthusiasts, programmers, and budding engineers.
Having built several simple Arduino robots with a few sensors, I wanted a platform that I could use to experiment with more advanced features. I settled on a robot that, for first steps, could stream high quality video and be driven over the network. …
Experiments with using off the shelf parts to assemble a robust filtering mask
At the time of writing, there is a worldwide shortage of personal protective equipment (PPE) for both medical professionals and the general population due to the coronavirus/COVID-19 pandemic. There have been stories in the news about healthcare workers hacking together face shields from office supplies, reusing N95 masks designed for a single use, and nurses using duct tape and garbage bags to make protective garments. You can’t even buy full face respirators designed for industrial work right now.
I started thinking about what a person could build themselves that might provide better protection than a cotton mask, without complex tools. I wanted something that could be easily built, completely disassembled for cleaning, and easily adapted to whatever filter material was available. I wanted it to protect the nose and eyes. …
You should let this experience change you.
The last two weeks have brought stunning change to America. The coming weeks will alter the way we view ourselves as a nation forever.
When it is over, when the storm has passed and the skies begin to clear, remember.
Remember wondering if you’d be able to get sufficient food for your family, for the first time in your life. Remember the shock of not being able to buy bread, or meat, or flour. For many, this is not the first time. For many, it is how they live all the time. Remember, and help where you can.
Remember what it was like to only see your friends and family on a computer screen, or through panes of glass. When you have the opportunity to sit around a table with them with good food and a glass of wine, be grateful. Savor it. It is never a given. …
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