This is a legacy post, written originally in 2005.
I, Nick Touran, built a bubble wall. You can build one yourself if you want. You can follow my example.
What is a bubble wall?
Basically, a bubble wall is a thin, clear wall of any size that is filled with water. Bubbles rise up throughout the entire wall and are lit up. It is basically an inch thick empty bubbling fish tank. I saw a 6-foot tall one in Las Vegas for $2,500 and decided I would just make my own. Mine will be a little smaller so that I can transport it.
Seeing radiation with your own eyes is incredible. It wows everyone who sees it, and is a perfect ‘hook’ to bring people over to your nuclear education table. “Hey, you guys want to see some radiation?”
I’ve used a normal dry ice cooled cloud chamber many times in science demos at corporate family nights, at demo tables at the Pacific Science Center, at schools, and so on for many years. You can still find dry ice at a number of grocery stores, but it seems to be getting more difficult. Plus, the dry ice runs out after a few hours, and you have to get more. I’ve heard of people using thermoelectric cooler (TEC) pads for this and thought I should try it out.
Being a nuclear engineer, I thought it’d be fun to find some Uranium in the wild just out there in the nature, sitting somewhat dormant since it was made by neutron star mergers and giant supernova billions of years ago. I just wanted like a tiny rock with some uranium ore in it.
I found an old document from 1957 describing where Uranium had been found in Washington State. The vast majority of it is around Spokane in Eastern WA, but there are a few spots closer by worth maybe checking out.
The ones up in the central cascades all looked to be in the Galena area, which is difficult/impossible to get to at the moment due to the washout on the index/galena road.
I thought I’d go for the one East of Rainier, which is on National Forest land and talks about super high-grade ore, but all the reasonable approaches require either a 14-mile one-way hike or access to closed-off lumber roads. I spent a lot of time on satellite maps before I convinced myself that you could not get past Ohop on the logging road, thanks mostly to this post. (Along the way, I learned about the Electron Dam down there, which seems pretty cool, as well as Vancouver Notch).
So anyway, this one by Bumping Lake West of Mt. Rainier looked much easier to access.
I don’t like the concept of decorative combustion that much, but I do have two tiki torches in my yard. I fired them up and checked my indoor vs. outdoor air quality sensors from my weather stations. Here are the results:
Reading the joystick in Python is super easy using pygame. I ran the demo code toward the bottom of the joystick page as my first step. It showed all axes and buttons working great out of the box with my controller.
Amcrest cameras support the ONVIF protocol. The python-onvif-zeep package supports sending ONVIF commands from modern Python (I used Python 3.10 for this project).
Specific example code demonstrating how to use the package from Python to send PTZ commands to the camera can be found e.g. here.
The package is pretty limited at the moment but does handle PTZ controls. It pans and tilts with the left joystick and zooms when you pull the right trigger and zooms out when you pull the left trigger. (Note that for this particular camera, zoom is purely software, but on an actual zoom cam it would work the optical zoom).
And there you go I saved myself $500 vs. getting one of those fancy joystick camera controller things.
I have a fancier PTZ ONVIF-compliant camera on order which is the real reason I wanted to try this out on the smaller cam.
A family member upgraded his stereo and offered me his Peachtree Audio Decco as a hand-me-down. I couldn’t say now because my previous hand-me-down has recently become buzzy. But, in order for it to work with my home automation setup, I needed to be able to turn it on and off, switch inputs, and change volume from my Home Assistant home automation system via my Raspberry Pi. I useLIRC for this but there is no remote config for the Decco. So I used the remote and recorded the pulses.
Using irrecord didn’t go that well. The dots were coming in but very slowly. I’d have to sit there for 10 minutes pressing in order to get enough dots for it. So I used mode2 to record raw commands on my pi. Then I hand-edited it to have the right format for a conf file and then ran irrecord -a on it to convert it to actual codes.
Since the LIRC remote DB hasn’t been updated since 2018 and has a few open merge requests, I figured it’d be easier to just post the file here for the next person who needs it. It works great. Here you go.
I have some of those mini-split Fujitsu heat pumps in my house that have infrared (IR) remote controls. This post explains how I set up my smart house to be able to automate the heat and air conditioning with a raspberry pi and Home Assistant.
I rigged up some holiday lights that switch between a number of color palettes based on what holiday is coming up next. I used a $25 light strip, a $5 WiFi microcontroller (ESP8266), and Home Assistant to make it all happen.
Setting up the light strip
Using a “NeoPixel”-like addressable RGB light strip is pretty well-covered online these days. I got this waterproof one. I plugged in one of my ESP8266’s and loaded it up with some demo code from the FastLED library. I bought an outdoor waterproof enclosure for the 5V power supply and ran outdoor wires in a small trench over to my fence, where I then used one of these outdoor wire coupler things to both protect the connection and store the ESP8266 itself.
My mom has used Windows computers since the early 1990s. During a visit in October, 2021, I set her up with a Linux desktop computer as her daily driver, and so far she loves it.
My mom is by no means a computer power user, but she does do most of the basics that people do. Email, zoom, chat, read the news, check the weather, print and scan stuff, watch Youtube tutorials, go on Facebook, etc.
I plugged my Geiger counter’s audio cable into my oscilloscope just for kicks the other day and saw ~9V pulses coming out when it occurred to me that I could easily read those into an Arduino or Raspberry Pi or ESP8266 microcontroller and respond to them. As a demo, I made a hardware random number generator (HRNG) out of a esp8266.
I like the concept of measuring flows and so have sensors on my water main and my electric mains. Naturally, I wanted to add a reading of how much bandwidth I’m using and get it displayed in my living room. I already have the following in place:
A year ago I built 2 DIY weather/air quality sensor packs to monitor the ambient conditions inside and outside, including carbon dioxide (CO₂) levels. Meanwhile, I got a COVID-puppy who sleeps in a covered dog crate. I got to wondering what kind of CO₂ levels that crate got up to at night. So I measured it.
I just slipped the sensors under the cover like this and let it run all night.
I graphed the readings from the previous day (outside the dog crate) and then inside the dog crate, as indicated with the arrow. As you can see, CO₂ levels did spike quite a bit but did not get above 2000 ppm. For humans, this would be expected to cause drowsiness and complaints about stale air, but would not be harmful.
So in conclusion, a mostly-covered dog crate isn’t deadly, but may be unconformable. I will be opening the back panel at least. I’m a little worried that if the cover was placed so that there were fewer gaps, it could get much higher.
Since the product is no longer sold on Amazon, I am left with putting this product review here. I got a bunch of GE smart toggle switches back in 2016 and installed them in various smarthome builds. Then, just yesterday (2021-03-14), I was (ironically?) installing a different smart switch on the same circuit. I turned the breaker on and off a handful of times while installing/testing the new one. And then I heard a clicking. Click… click…click… click… click… like a metronome with 1 second delay. It was the GE 12727 smart toggle from 2016. It was just clicking and clicking and clicking. At first I thought for sure the new switch was interfering with it somehow so I disconnected it and the clicking continued.
I guess a 5-year life isn’t terrible, and that one of the issues of going all in on home automation is that complexity generally leads to lower reliability. I can handle replacing the ones in my home, temporarily with the OG dumb switches and then with new upgrades (I’ve been using Inovelli switches recently based in Michigan what what!, which have cool extra features). It’s a lot more problematic when something like this happens at my mom’s house and she has to like call an electrician.
Today I accomplished my big summer goal of paddleboarding from Lake Union in Seattle to the Puget Sound and back. This is my story.
Paddleboards cannot go through the locks
I’ve seen kayaks go through the locks but never paddleboards. Upon looking into it, I was able to confirm that paddleboards are not allowed in the Chittenden (Ballard) locks. So I got out a map to look for ways around the locks. I found a little street end park at 28th Ave NW and figured one of the various public shores to the north would have beach access. I was hoping it would be the first few, but they are on pretty significant bluffs. So I found that the best re-launch spot is a full 0.7 miles down the road, at the NW 57th St. beach.
The wind forecast for today was really calm and that’s what I had been waiting for. This kind of journey would be too hard for me if I had to fight strong winds in one direction or the other. I left around 8:30am.
LIS3DHTR 3-axis accelerometer. I read that this one might have the noise and sensitivity characteristics needed to try to measure some seismic activity (I live in Seattle, after all)! Notably I did not research this very seriously so we will see. Note: this chip has three analog-to-digital inputs but they are not available in the Grove package that I got. Prefer Adafruit)!
BME680 gas sensor for Temperature, Humidity, Air Pressure and Volatile Organic Compounds (a rough measure of air quality)
HM3301 Laser PM 2.5 Air quality sensor for measuring particulates in the air at sizes PM1, PM2.5, and PM10. This will be really useful to have one outside and one inside during fire season so I can see how dangerous the air is outside and how well my air filters are doing inside.
The ESP8266 Microcontroller. I absolutely love the ESP8266 for being the brains of things like this. I had used one for my doorbell sensor, my mom’s boiler controller, and various other things. Programming this to read all these sensors is a major part of this project.
Geiger Counter with USB interface. I had to reverse engineer the protocol coming out of this USB port and was able to do it using pyusb but that’s another post in itself. Unfortunately, I don’t think I can actually read this USB port too easily on the ESP8266 so I might have to slap a Raspberry Pi in here, or some other USB interface. This is a big TBD.
(Not pictured, see below or rain sensor post): Infrared rain sensor from Hydreon in MN. This is actually a sweet sensor. It shoots IR light around the dome and when water hits it, refraction of IR changes and the response at the receiver can pick up even a single raindrop. Garsh-darned epic!
As you can maybe see, I got most of these sensors with I2C interfaces from Grove, which has a really nice ecosystem with easily-interconnectable sensors. This is my first experience with the Grove ecosystem, and I love it. Very clean. Note, however, that I2C is not good for off-board sensors (so maybe not a great choice for the sunlight sensor which should be placed higher up).
I had a flood in the garage the other day and realized how great of an investment my flood sensor had been, saving me literally weeks of time and thousands of dollars in repairs. As I considered buying more flood sensors to cover more parts of the house, the thought to put a flow meter on the main water inlet to the house popped into my mind. It’s not quite as clear of a signal as a flood sensor, but if I detect flow when everyone is asleep or when on vacation, I can be sure that something is going wrong and have Home Assistant give me an alert.
I’ve been working on a home-brew weather station and was looking into rain sensors when I discovered that you can get infrared (IR) rain detectors. A company in Minnesota sells one called the Hydreon RG-11. They shoot pulses of IR light around a plastic dome and monitor them on the other end. When rain hits the dome, the refraction changes and the pulses received are perturbed. This is nice because it’s very simple and has no moving parts. I figured I’d be able to find a way to read it into my weather station.