Overnight pulse oximeter tracks sleep apnea

Sleep apnea graph

At the start of the pandemic, I read a suggestion from a nurse that having a pulse oximeter would be a good idea. I’ve also had issues sleeping for some years including mild (and some not-so-mild) sleep apnea so I figured it might be good to document these. I bought a model which can be worn comfortably overnight and track the full night’s sleep, the Wellue/ViaTom SleepU P03.

The data it’s shown me is alarming. I have been having apnea events almost every night, some of these lasting long enough to dramatically drop my oxygen saturation. I’d been wondering why I’d suddenly find myself wide awake at 3 AM. Now I know it’s because I’d stopped breathing and my body struggled itself awake.

Though I’ve collected months of graphs showing a problem, I’ve not been successful demonstrating this during the VA sleep studies I’ve had done. I don’t do this every night but it happens with enough frequency that it makes it hard for me to feel rested in the morning. I’m hopeful that a future study will open the door to some treatment. A good night’s sleep is a fantastic gift.

Along my sleep apnea journey, I found the excellent OSCAR app, an open-source data visualization tool that gathers data from CPAP machines and pulse oximeters like mine.

Getting old is not for wusses.

COVID-19 life

It’s October 6th, day whatever of our home quarantine thanks to the COVID-19 novel coronavirus and President Trump’s utterly abysmal failure to confront it early on. We’ve been essentially holed up since March going out only for essential shopping, medical appointments, takeout or curbside food, and little else. My company shuttered its downtown Raleigh office in favor of an everyone-work-from-home model. I haven’t hugged my mom or dad in over seven months.

We do get out for exercise every weekend possible. Kelly and I have put a few hundred miles on our bikes riding the greenways. But I still won’t go into an office building or an enclosed space for any longer than necessary.

We’ve learned so much about COVID-19 since those early days. Poorly-ventilated spaces are the worst, particularly if they’re crowded. Outdoor activity is safest. Experts roll their eyes at the photos of people at beaches used to illustrate pandemic news stories, as those scenarios are among the safest.
Continue reading

Samsung Galaxy spying defeated?

As I’ve written before, I kept noticing ads pop up on Facebook and Twitter which seemed suspiciously as if they were triggered by conversations held around my phone. I got so fed up with this this summer that I briefly listed my Samsung Galaxy phone on Craigslist. And yet, something pulled me back. A friend pointed out that certain apps – even system ones – could be removed from the phone without actually rooting it. I have always been impressed with the Galaxy’s hardware; it was Samsung’s bloatware that drew my suspicion. Samsung’s locked my phone down so tightly that rooting it is out of the question. Perhaps this other method might work?

After carefully examining apps in Android’s app permissions page, paying particular attention to system apps (which usually are firmly entrenched and can’t be removed), my eyes focused on one quite innoculous one that called itself SmartThings.

I already tweeted my discovery of two separate SmartThings apps, each with wildly different permissions, but a search of the phone’s packages never turned up any of the more entrenched, system version of SmartThings.

After more Googling, I found the name of the offender, a mysterious package called com.samsung.android.beaconmanager.
Continue reading

How to perform music together virtually

Musicians together virtually


A retired music teacher friend, Ruth Johnsen, needed help setting up a virtual performance by her music students. Because I was eager to learn a new video editor and because it’s really impossible to say no to Ruth, I stepped up and took it on. For the past few weeks, videos from each musician has been filtering over to me and I’ve been learning all I can about stitching them together. Fortunately, the occasional karaoke videos I’ve created have given me a little insight into the best way to get this done. Here’s my recipe for successfully recording musical parts for a virtual performance.

Consistency is key. The video clips I was given all look and sound different. That’s to be expected from so many musicians and no way to use identical hardware and software. There are some aspects that can be easily standardized, such as:

Video orientation. Have everyone use either portrait or landscape mode. It will look much better. Purists insist on landscape but portrait can work, too. Whichever you choose, it’s best if everyone uses it.

Distance.
Be consistent with camera distance. If your phone or camera is too close, you will overwhelm the microphone; too far and you won’t be heard at all. You’ll also make work for the video editor as she has to scale or crop the video to make everyone look consistent.
Continue reading

Bypassing the AT&T Pace 5268AC Residential Gateway, Part I

Turn this into a high-tech doorstop


I’d been dreaming of getting fiber to my home for over a decade. It was that long ago that I spent my days hooking up ten-gigabit fiber connections to massive file servers at NetApp. I led a successful grassroots effort to lure Google Fiber to Raleigh, because competition can be a great way to spur innovation and investment. You can imagine in 2018 how excited I was to learn that fiber was coming to my neighborhood. While it wasn’t Google, it was AT&T. I swallowed my pride, quietly rescinded my ban of ever doing business with AT&T again, and signed up for their fastest package: symmetrical gigabit fiber. Cost was $80/month initially and thereafter $90/month. I’m sure I’m one of the few in my area who max it out. Hey, geeks gotta geek.

Why bother?

While I’m happy to use up as many AT&T bits as possible, I still don’t entirely trust the company (though I do trust them more than Time Warner Cable (TWC), a.k.a. Spectrum, and this as you know is not saying much). While providing direct access to my home network to a major telco may be a bit on the paranoid side, a number of security vulnerabilities have been discovered with other AT&T devices. Though AT&T might not be snooping around my network, I could not be entirely comfortable that hackers wouldn’t. AT&T’s RGs were discovered to have the built-in ability to do deep packet inspections (DPI) themselves, being able to snoop on the network traffic of its customers. For this and many other reasons, I just don’t trust any devices on my home network that I do not control.

I kept a firewall between TWC and my network for this reason. AT&T wants you to use their device, which they call a “Residential Gateway” or RG, as the firewall. It also acts as a WiFi point, DHCP server, and the like. This may be fine for most people, but I am an uber power user. As an engineer, I want to squeeze the maximum performance out of my networking. I will happily void the warranties on my networking gear. I didn’t spend time tuning my home firewalls for maximum throughput just to discard them when some corporate box comes along. This just won’t do, you see.

The Power User’s approach

My first approach was to switch things over to my TP-Link AC1750 access ponits, running OpenWRT. While my AC1750s could keep up with the slow (300 Mbps) speeds of cable Internet, they were balking at gigabit speeds. The hardware acceleration the AC1750s utilize require proprietary drivers which OpenWRT does not provide. It was time to list them on Craigslist and try something new.
Continue reading

The Evocacs Deebot Orzo 920 robot vacuum

The Evocacs Deebot Orzo 920

My membership warehouse company, Costco, sells both the iRobot models but also the Ecovacs brand. I was intrigued so I brought home the Ecovacs Deebot Orzo 920. What do I have to lose, with Costco’s generous return policy protecting me? I ordered the Orzo 920 online and waited patiently for it to arrive.

The Orzo 920 is almost perfect as far as robot vacuums go, though I’m not sure why is has such a long name (how many brand names does one robot need?). A Chinese model, it nevertheless has clearly-written documentation and labels. The box contained the robot, charging dock, booklet, two HEPA filters and a tool for cleaning the brushes. Instinctively I set up the charging dock and put the robot on it, not realizing I had to flip the red switch on top to actually turn it on.

Modern robot vacuums need Internet access, so I had to go through steps to connect it to my home network. I downloaded the Evovacs app for my Android phone and set the vacuum up to advertise its WiFi signal. Connecting it to the app was simple and quick.

Once the Orzo was charged, I used the app to set it up. The Orzo uses LIDAR laser ranging to map the floors of your home. It maps your home the first time it’s run, after which you can edit the map to divide areas, mark off spots with “virtual boundaries,” and make other adjustments. Different advanced vacuums use different technologies to map rooms (iRobots use a visual camera) but in my experience the LIDAR is tough to beat. It was a treat to watch as the app filled in walls as the robot proceeded around the room. It does an amazingly accurate job figuring out where it is and what the room looks like. I could tell this was not a robot that would ever get lost on the way back to the dock.

One thing I learned right away is that the initial mapping takes longer than a normal cleaning. This may just be my experience but I wanted it to be thorough in its mapping at the expense of deep cleaning the first time. I discovered an option in the app’s settings which allows you to set the vacuum’s power on the “Quiet” setting. This uses far less battery than the normal power modes so I was able to get the vacuum to completely map my floor without having to stop and charge mid-way.

Multiple floors are supported, so once the Orzo had mapped the downstairs I moved the dock and vacuum upstairs and had the Orzo map it, too. Only two maps seem to be in the app so if your home has more than two you might be out of luck.
Continue reading

Robot vacuums – The Ecovacs Deebot Orzo 920 vs. Roborock S4

Many years ago through a “Woot-off” clearance sale, I became the owner of a first-generation iRobot Roomba robot vacuum. It was novel advanced for its day, bouncing randomly around the room, but it frequently either got stuck somewhere or lost its way back to the charging dock, sending me on a whole-house search to find it. When the battery died I packed it away and switched to old-fashioned vacuuming.

With the recent addition of two dogs to the family vacuuming has become a priority again. To keep up without spending an hour manually pushing a vacuum around the floor, I revisited the state-of-the-art for robot vacuums. I quizzed my friends with vacuums to see what they liked about theirs. I read several web reviews and product reviews.

iRobot’s latest models seemed okay but didn’t wow me. They seemed to have a high price tag for what they offered. iRobot is no longer the only game in town, so I thought I’d look at the competition. The Evocacs Deebot Orzo 920 is sold at Costo and seemed like a good candidate, so I ordered one. I also read some great online reviews of the Roborock S4 so I ordered one of those, too. After a few weeks with each I’ve decided to post my reviews of them, starting with the Orzo 920. I’ll post the link to my Roborock review here once it’s done, too.

Dogs join the family

January marked a year since we said goodbye to our Black Lab, Rocket. The house has been clean but quiet since then but facing the prospect of an emptier nest this fall, Kelly and I began kicking around the idea of another dog.

In February, a friend who is a volunteer dog rescuer brought over a dog she was trying to home. While this female dog seemed okay, she was unusually focused on tracking down our porch cat and seemed to pay us little attention. It would have been nice to help our friend out by taking in this dog but that spark I expected to feel just wasn’t there with this particular dog. Our search resumed.

One of Kelly’s friends mentioned to her that there were two dogs needing a home. These dogs had been abandoned at a neighbor’s boarding service ad were part of a trio of dogs, one of which found a home with another neighborhood friend. We arranged for them to visit us so that we could decide which one we would adopt.

Our boarding service friend Laura brought the dogs, Abbot and Tobin, over March 1st and gave us their long backstory. Both are hounds who had been in the kennel for the best part of a year. One was a stray and the other was part of some kind of dog-hoarding situation. They’d been together for months.
Continue reading

On another planet

One friend on Facebook who normally stays genteel watched one of Trump’s coronavirus press conferences and then unloaded on him in a post:

Watching the daily Presidential press conference on the Corona virus. Sorry Trump fans but how pathetic can one be. So far its been me, me, me!! How great I am, how much I’ve done, previous administrations are responsible, Governor’s are totally responsible. Everyone but me is responsible!! Forget the 30,000 dead, 700,000 infected and continuing. Outrageous!! Sorry for venting on my few posts.

Most of the responses to his post were in agreement, but one of his friends responded with this:

He’s actually none of those things and he’s doing a great job he’s he is talking himself and the task force up a lot but only because this is his only chance to defend himself the media totally lies. They are blaming him for a delayed response to the handling of the virus when in fact Dr. Fauci said on Feb. 29th that there was no need to change our behavior. Dr. Birx also supported the White House response and timeline at the press conference the other day. No one has a crystal ball and no one knew how bad the virus would be our president took decisive action and he was a genius in partnering private and public partnerships to get all the PPE and ventilators and things that we need acted very quickly he does deserve a little credit and he’s been working really hard and it’s very unfair shouldn’t matter what your politics are we should all be coming together in this time of crisis.

This totally blows my mind. It’s like this person is on another planet, viewing a different president than I am.
Continue reading