Category Archives: General Tech Stuff

Setting up run intervals on Garmin watches

(Disclaimer: I am not a coach or even especially knowledgeable; in fact everything I say in this post could be completely wrong. Don’t blame me if you create an interval that causes you to inadvertently run an ultramarathon.)

If you want to be a faster runner, you have to run faster. Unlike many other areas of endeavor, though, the best way to get faster is to train in intervals. Instead of going out every day and knocking out the same distance on the road, almost every runner can benefit from mixing those steady-state runs in with shorter-distance, higher-intensity work. For example, my coach might give me this: “2 mi WU, 6 x (2:00 @ 10K, 2:00 slow), 1mi CD.” Translated, that means “2 mile warmup at an easy pace, 6 intervals where each interval starts with 2 minutes at your 10K pace and then a 2 minute slow run, followed by a 1 mile cooldown.”  Tracking intervals is a pain in the butt, though, which is why many runners use a track– then they know to run 440, or 880, or whatever. Distance-based intervals are OK but I find track running to be even more boring than treadmill runs; I’d much rather do my intervals outside. Luckily, Garmin has my back: you can build a structured workout, then send it to your watch. When you’re running, the watch will tell you what to do. It’s magic! Because I am a nerd, I was excited when I found this feature a couple of years ago, but I find that lots of my running friends don’t know that it exists.

Garmin lets you build structured bike, run, or swim workouts that include an optional warmup, zero or more individual steps, zero or more repeats (which is the actual interval– you do X, then you do Y, repeated Z times), and an optional cooldown. Once you create the workout, you can send it to your device and it will guide you through the workout. Note that there are a lot of differences between run, bike, and swim intervals and how they are presented on various devices; for now I want to focus on the simplest case, setting up a simple run interval.

Let’s say that you want to do a simple interval workout: a 10-minute warmup, then 6 intervals at 5K race pace, then a 10-minute cooldown. I’ll pretend that you want 2 minutes at race pace and a 2 minute cooldown in each interval. Here’s how you’d set that up.

Start by logging into the Garmin Connect website. Once you’re there, click on the hamburger menu (3 parallel lines in the upper left corner), then and scroll down until you see “Workouts,” then click it. That will bring up the workouts page.

the workouts list in Garmin Connect

Click the “Select a workout type…” menu and choose “Run,” then click “Create a Workout.” You’ll see the workout creation page. Garmin helpfully assumes that you’ll have a warmup, a single run step, and a cooldown. Each of these items is color-coded.

A new blank workout for you to customize

Delete the single run step by clicking the “X” at its right edge, then edit the warmup and cooldown to include the times you want. You can also specify distance– wherever you see “select a duration”, you can choose to base the length of that item on distance, time, speed, pace, or just pressing the lap button. Use the pull-down menus in each section to fill out the workout you want.

Start with the warmup and cooldown

Now for the magic: click the “Add a Repeat” button and a new section will appear.

Oh noes, this is all jacked up

There are several things wrong with this, though: the repeat is in the wrong place, it’s for the wrong number of reps, and the intervals we want aren’t there. Luckily, this is easy to fix:

  1. Use the + and – icons at the top of the repeat block to set the correct number of reps.
  2. Use the “Select a duration…” pulldowns in the “run” and “recover” sections to set the right durations.
  3. Use “Add More…” in the “run” section to add the correct pace:
    1. Click “Add More…”
    2. The “Select an intensity target” pulldown will appear.
    3. Click it and select “Pace”, then fill in the target pace range you want. (Note that you can also set intervals based on heart rate zone and a bunch of other metrics).
  4. Repeat step 3, but this time for the “recover” section.
  5. Click and drag the little grabby thing (next to where you see “Repeat N Times” in the repeat block) to drag it into the correct position.

When you’re finished, here’s what your workout will look like:

All done! (Bonus points if you notice the one other change I made)

Now you can save the workout.. but before you do, use the pencil icon next to the “Run Workout” title to change the name of the workout so you’ll be able to identify it. Once that’s done, click “Save Workout.” At this point, absolutely nothing useful will happen when you look at your watch, because there’s another required step: you have to transfer the workout to the watch. The easiest way to do this is with the Garmin Connect mobile app, although you can plug your watch in with a cable if you prefer. As I write this, you can’t create interval workouts in the app, which is too bad. Here’s how to perform the sync: (These instructions are for the app on iOS; I don’t have an Android device so I have no idea if the UI is the same or not.)

Start the app, then click on the “More” icon (the three little dots) in the bottom navigation bar and tap “Workouts”. You should see the new workout you just created in the list:

The new workout is available to sync

Tap the new workout, and you should see the workout itself. In the upper-right corner of the screen, there’s a little icon showing an arrow pointing into a phone. That means “sync,” although why it shows a phone and not a watch is a mystery. Click it, then you’ll see a page showing all the devices your app knows about.

Here’s your workout, nearly ready to go

Select the device you want and tap “Send”.

Select the target device

Wait a minute, then check to see if the workout’s on your watch. On the Fenix3 HR, you do this from Training > My Workouts > Running. Scroll through the list until you see your workout, then hit the “start” button and you’re all set.. happy running!

Ta da


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Training Tuesday: IoT insecurity, fitness division

There’s lots of hype about how the Internet of Things (IoT) will make our lives better, and much of it is true. For example, my house has two Internet-connected thermostats that I can use to see and change temperature settings— that way I can keep the house uncomfortably cool or warm when I’m not there and adjust the temperature remotely so it’s comfy when I get there. Fitness devices are definitely a well-established part of the IoT; companies such as BodyMedia and Garmin have been making devices that can connect, either on their own or through a PC or smartphone, to Internet services for a while. That market has been growing very rapidly over the last few years (some estimates put it as $3 billion in 2015), so some bright folks at Open Effect (funded in part by the Canadian government) decided to take a look at the security of IoT-connected fitness devices.

The results (full report here) are pretty horrifying:

  • Many devices transmit their Bluetooth MAC IDs at all times that the device isn’t pried, and those IDs never change, so it’s easy to track someone through rudimentary Bluetooth beacon monitoring.
  • The Jawbone and Withings fitness services don’t do a very good job of data validation; the researchers mention telling the Jawbone service that their test user walked 10,000,000,000 steps in one day, and the service happily accepted that. Worse still, they were able to inject fake data, generating records of “a person taking steps at a specific time when no such steps occurred.” Given that this data has been used in both criminal and civil trials in the US and Canada (see the extensive footnotes in section 1.4 of the report), this is pretty awful.
  • Garmin and Withings don’t use HTTPS to protect data in transit. Given that I wear a Garmin watch and use a Withings scale daily, I have a problem with this. The researchers only studied the Garmin Connect app on iOS and Android, but if I had to bet, I’d guess that my Garmin watch (which has Wi-Fi) isn’t using HTTPS either.

Apart from calling Garmin to yell at them, I’m posting this mostly to point out yet another case where the rush to get things on the Internet may have unintended consequences. While my individual fitness data is not necessarily something I mind being visible, I don’t like that these manufacturers have been so sloppy. I can understand not wanting to implement HTTPS on a very low-power device but there’s no excuse not to implement it in a mobile app, for crying out loud.

Meanwhile, if I ever need to, now I know how to challenge any fitness-related data that may be introduced in court.

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Flying Friday: the avionics brain transplant begins

I fly a 41-year-old airplane. Not that there’s anything wrong with that. As I’ve said before, there’s something to be said for mature technologies, and the economics of general aviation are such that there’s no chance I’ll be buying a new airplane any time soon when even an entry-level Cessna 172 costs north of $400K. Because new aircraft are so expensive, there’s a lively market in refitting and upgrading existing airframes. The engines, paint, interior, and avionics on an airplane can all be replaced or upgraded at pretty much any time, and the longevity of the basic airframe means that I can comfortably expect to get another 20-40 years out of my existing plane if I take good care of it.

With that said, newer airplanes have some major advantages, many of which (built-in cupholders, leather seats, ballistic recovery parachutes) aren’t available for my plane. After flying 706 for about a year, getting my instrument rating, and taking more and longer cross-country trips there were a few things that I wanted to add to make instrument flight easier and safer. My co-owner Derek and I spent a lot of time hashing out what we wanted vs what we could afford vs what we could live with. Here’s what we decided.

First off, we knew we’d have to meet Yet Another Unfunded Mandate. Starting in 2020, all airplanes that operate in controlled airspace (meaning the “Class B” and “Class C” airspace surrounding major airports and most cities) have to use a system called ADS-B. The FAA has delusions that ADS-B, which requires every aircraft to continuously transmit its GPS-derived position and velocity, will replace radar. It probably won’t, but that’s a topic for another post. Equipping a plane for ADS-B  requires two pieces:

  • a GPS system that uses the FAA’s Wide Area Augmentation System (WAAS) to provide high accuracy position and location data. The WAAS system combines satellite GPS data with position data from precisely surveyed ground stations to provide sub-meter accuracy.
  • an ADS-B Out transmitter that sends ADS-B data, including the WAAS GPS data

There are lots of ways to get these two parts, ranging in cost and complexity from “absurd” to “merely unpleasant.” The two most popular ways are to install a new transponder that includes a built-in position source or install a separate WAAS GPS and a little box that transmits ADS-B Out without touching your existing transponder. You can also get weather and traffic data using ADS-B In; that requires an ADS-B receiver and something to display the received data on. Right now, I use a Stratus receiver (the original, not the fancy 2S) and ForeFlight on an iPad for ADS-B In… but, as with many other government programs, there’s a huge catch. You get weather data for free, but you only see ADS-B In traffic if there’s an ADS-B Out-equipped airplane near you. This was supposed to be an incentive to get people to add ADS-B Out, but as a practical matter it means that ADS-B In is currently only useful for passive receivers like my Stratus in areas where there are already lots of ADS-B Out airplanes.

Next, we wanted the ability to use WAAS instrument approaches. I love the precision of ILS approaches, and use them whenever I can, but most airports don’t have an ILS, and those that do won’t typically have more than one. However, a growing number of airports have approaches that offer precision vertical and lateral guidance if you have a WAAS GPS. To be more precise (see what I did there?), we wanted to be able to fly LPV approaches so that we’d get precision vertical guidance for approaches where ILS equipment isn’t available. With WAAS equipment, you can also get an advisory glideslope, which gives you non-precision vertical guidance to help keep you from smashing into things.

Finally, we (well, mostly I) wanted to improve the autopilot’s ability to track instrument approaches. The approach phase of single-pilot IFR is a demanding and busy time, and it’s easy to make mistakes. Our existing autopilot can fly a heading, keep the wings level, and hold an altitude, but when you get to a complex approach, being able to let the autopilot turn the airplane based on GPS steering is very helpful because it frees up time and attention for vertical navigation, approach prep, and other critical tasks.

After a lot of back-and-forth, an immense amount of comparison shopping, and lots of head-scratching, Derek and I decided to send 706 to Sarasota Avionics to have the following installed:

  • An Avidyne IFD540 WAAS GPS. I preordered one of these back in 2012, well before I even had my pilot’s license, on the theory that I could always sell it later. The IFD540 is much more capable than the Garmin GNS530 and, to me, is easier to use than the Garmin GTN750. It’s also less expensive to buy, requires less expensive data subscriptions, and provides some much-needed market competition for Big G.
  • An Avidyne AXP340 transponder. The AXP340 transmits ADS-B Out, but it requires a separate WAAS GPS. In our case, that’d be the IFD540. There’s a whole complex mess of rules for which transponders can be legally used with which GPS position sources– basically, only combinations that have been certified by the manufacturer and registered with the FAA can be installed and used, even though other combinations may work just fine. Avidyne’s products are obviously certified to work with each other.
  • An Avidyne MLB100 ADS-B In receiver. Derek talked the Avidyne guys into giving us one of these for free if we bought the preceding two items. With this, the IFD540 can receive and display traffic and weather information. It is extremely useful to see this data overlaid on your primary map, especially because you can “rubber-band” your flight route to deviate around weather and traffic as needed.
  • A DAC GDC31 roll steering converter (which most people just call a GPS steering, or GPSS, adapter). Our autopilot, bless its heart, is the most analog device I think I currently own. It works by sensing voltage output from the directional gyro and course deviation indicator (CDI). To fly a particular course, you twist a knob on the DG to set the heading indicator, or bug, to the desired course; you can also have the autopilot track a VOR or even an ILS localizer, which it does by looking at the voltage used to drive the deflection on the CDI. One thing it can’t do, though, is track an actual GPS course. If the GPS route calls for you to fly a heading of 175 degrees, and the heading bug is set to 95 degrees, guess where you’re going? The GDC31 fixes that by adapting the digital steering commands output by the IFD540 into voltages that the autopilot can understand. I’ve used GPSS in other airplanes before and it’s a great experience– smooth, solid tracking with no “hunting” and accurate turn anticipation.
  • An Avidyne AMX240 audio panel. We’d been talking about replacing our ancient mono audio panel with a nicer unit that would give us better audio quality, and the marginal cost of adding the panel at the same time as the other equipment was considerably lower than doing it later.

The IFD540 + AXP340 combination gives us ADS-B Out, so we’ll be legal. The IFD540 + MLB100 gives us ADS-B In (with the added bonus that the IFD540 has wifi, so it will be able to feed all sorts of useful data to portable devices in the cockpit). Finally, the IFD540 + GDC31 gives us full two-axis autopilot coupling. I think, but haven’t verified, that it will also give us the ability for the autopilot to track altitude changes as expressed by the glideslope. The existing autopilot can track an ILS glideslope, and the IFD540 can provide a glideslope for LPV approaches (and an advisory glideslope for LNAV+V) so I think it should “just work.”

This seems like a huge list of expensive stuff (and it is)– one question that immediately comes to mind is “why bother with all this stuff when you could just use an iPad?” The problem is spelled F-A-A. First, there are no portable ADS-B solutions that are approved to meet the 2020 mandate in Part 23 aircraft. That’s a fancy way of saying that an experimental or homebuilt airplane can use equipment that’s not approved for factory-built airplanes. That also wouldn’t give us WAAS approach capability; even though there are portable WAAS receivers (including this watch!) you can’t use them to fly approaches. While there’s been lots of flailing in the aviation press about the need for cheaper, better-integrated ADS-B solutions, it’s also true that we’re getting a lot of other capability out of the upgrade that we’d miss if we went with a simpler ADS-B-only installation.

Along with the avionics themselves, of course, there are lots of little things– antennae, cables, and so on– that have to be installed and tested. That’s why we expect the upgrade to take an eye-popping four weeks– and that’s assuming everything goes well. Stay tuned!


Filed under aviation, General Tech Stuff

Garmin Fenix 3 drops data from Stages power meter

I’ve been ignoring this problem for a while, hoping that it would be fixed in a firmware update, but it persists, and I finally got aggravated enough with it to write this post (and to engage Garmin support). The problem is simple: my Garmin Fenix 3 triathlon watch will not reliably record data from the Stages power meter I have on my bike.

A quick digression: there are two major standards for wireless exercise sensor connectivity, Bluetooth Low Energy (aka BLE and Bluetooth 4.0) and ANT+. Some devices support one or the other, and some devices support both. For example, my heart rate monitor (the excellent Scosche Rhythm+) simultaneously transmits both ANT+ and BLE signals, but my Wahoo speed/cadence sensor is ANT-only. When I ride, I usually use two devices: my old iPhone 4 on the handlebars, in a Wahoo case that has a built-in ANT+ adapter, plus my Fenix 3. The iPhone is too old to use BLE, and turning on BLE on the Fenix 3 dramatically drops its battery life, so I’m using ANT for all the sensor data. Having two devices means that sometimes I forget to start or stop one device or the other at various points, so I often have mismatched data between the two.

A picture will illustrate the problem most clearly. When I use the Fenix 3, I end up with ride data that looks like this:

Bad power data is bad

As you can see, the power graph has a few spikes with lots of flats– and an average power of only 23W. (I’ll get to why the average is important in a minute). By contrast, here’s what the ride looked like when captured with the Strava app on my iPhone 4. Note that the power data much more closely tracks the speed, cadence, and HR data.

That's more like it

So why is this important? First of all, as a techie, it annoys me when two things that are supposed to work together won’t. More importantly, I actually use the power data from these rides in two ways. While I’m on the bike, I use it to gauge and adjust my level of effort. For example, yesterday’s ride was pretty windy, so I tried to hold a steady 190-210W while riding into the wind, keeping my level of effort constant and accepting whatever speed that gave me. After a ride, my coach and I use the power data to plan my recovery time and to identify areas where I need more practice (e.g. climbing hills). Having inaccurate or dirty data makes both of these uses impossible.

The Stages power meter support FAQ suggests moving the watch around, but I haven’t tried that yet. My troubleshooting efforts so far have been limited to changing the battery in the Stages and making sure the Stages and Fenix both have the latest firmware. I’ll see what Garmin support has to say. Hopefully they have a magic fix; I have a very early-model Fenix 3 so maybe they’ve made some improvements since launch. Until then, I’ll keep recording each ride twice and keeping the cleanest data.


Filed under FAIL, Fitness, General Tech Stuff

iOS charging woes

I have been meaning to write a long article about why I moved from Windows Phone back to iOS, and the good and bad parts of the transition, but I’ve been too busy to bother. I do have time for a quick rant, though: damn, I am tired of having charging problems.

See, Apple has this logo certification program called “Made for iOS.” Join it, and your devices (which might include chargers, cables, etc) can be certified as compatible with Apple devices, and you get a cool logo. Sure, it costs you a few bucks to sign up and get certified, but it’s cheap insurance. Nice line of chargers and cables you’ve got there. It’d be a real shame if anything happened to it.

On my last two road trips, previously-working cables have suddenly started producing the infamous “this accessory may not be compatible” message. Once that happens, it’s game over. The phone (or iPad) will no longer charge from that cable. If you happen to be on a road trip, well, too bad. Luckily I had a spare, but I am now nearly out of working cables, and there’s no guarantee that the name-brand cables I bought from Amazon (all of which were from vendors who claimed to be MFi certified) will keep working. Of course, because it’s Apple, there’s no way to override this dialog, ignore it, or force the device to talk to a tainted cable– once the cable is blacklisted, it’s no longer usable with that device at all.

The worst part? I’ve seen many reports of this happening to people who bought cables and chargers from the Apple store. Since I am unlikely to ever do that I’m not too worried, but I hate the precedent, and the inconvenience factor has been pretty stunning compared to my easy prior life of using micro USB cables with my Lumias. While I understand Apple’s desire to protect the IP embodied in the Lightning interface, and while I even believe that part of the rationale behind blocking non-certified devices is to prevent bad customer experiences, the whole thing has left an unpleasant taste in my mostly-discharged battery.


Filed under FAIL, General Stuff, General Tech Stuff

Fixed: Surface Book doesn’t recognize docking state

I got a shiny new Surface Book on Monday and started using it immediately… more specific notes on it later when I have more time. I ran into a problem today, though, and wanted to document what I found.

Symptom: the touchpad and keyboard don’t work. The clipboard switches to tablet mode (if you’ve enabled automatic switching). You can’t use the base unit’s USB ports. The taskbar “undock” icon shows that the base is undocked.

Cause: beats me.

Resolution: boot into the system BIOS by turning the machine off, then holding the power and volume-up keys for 15 seconds. When you get into the BIOS, just exit BIOS setup and the machine will reboot normally. There’s a thread here that outlines the exact procedure.

Overall, I love the machine: the form factor, build quality, screen resolution, performance, and trackpad are all superb. I expect this kind of temporary hiccup, so it hasn’t put me off at all.


Filed under General Tech Stuff

Windows Hello and Microsoft Passport intro

I’ve been working on a white paper explaining how Windows Hello and Microsoft Passport work together in Windows 10– it’s a really neat combination. Over at my work blog, I have a short article outlining what Hello and Passport are and a little about how they work (plus a bonus demo video). If you’re curious, head over and check it out.

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