Solar Charging details

So, one of the first problems we ran into with the RV was a steady drain on the engine battery. One of the main reasons for getting the RVwhisper all setup was to monitor this data remotely and see if it was real or just typical lead-acid battery flakiness.

After replacing the batteries to eliminate old batteries as a cause, I started collecting data, and noticed the following pretty quickly. Here’s a graph of the House battery (2 6V Batteries in series) and the Engine battery.

(Green in House Battery, Red is Engine Battery, grey bars indicate nighttime so you’re seeing the voltage over about a week).

Nothing was on or running during this period, the RV was just sitting in storage and the RVWhisper & Modem were plugged into a portable battery (another article). You can see pretty clearly that there’s a substantial drain on the engine battery here, dropping about 0.3V in a week compared to the House Battery.

To some, this is a known problem. Lots of things in the RV continue to run when it’s "off", things like smoke detectors and such. To avoid showing up to a dead battery, many people recommend disconnecting the battery. That seemed a bit extreme to me, so I moved onto the next solution: Solar Suitcase.

Solar Suitcases are popular in the RV world for this very reason: Small portable solar panels with the charge controllers and all integrated, that you can hook up via giant gator clamps to your battery and provide some offset current during the day. After a bit of research, I went over board and bought a big 200 watt/20 amp Renogy panel.

With that hooked up, I’ve never had any more battery problems. But I did notice a new interesting quirk in the charging graph, that looks like this.

Every day there’s a swift uptick in voltage to a peak just under 14.5V, then it falls back to just under 13.5V to spend the rest of the day, before falling back down to 12-and-change at night. What’s going on here?

I suspect that the first 14V spike is the actual charging step. Measure a running car battery with the alternator going and you’ll read something similar. This is when it’s actually pumping a fair bit of juice into the battery to charge it up. Given that I went overboard with a big 200W solar panel, it doesn’t take long. Then it drops to this 13.5V range, where the battery is basically "full" but it’s still absorbing a tiny bit of power to counter whatever drain is coming from the RV. Then it simply quits charging overnight when there’s no sun for the solar.

Seems legit, but can I monitor this more usefully? A bit of python and SQL query later, and I’ve added a new tool to the RVwhisper-Monitor package, You can run it independently or have it added to the output of the slope tool, and get a chart like the following.

This shows the hours of sunlight in the day (actually seconds, I need to fix that sometime) as the faded red bar (Yes, the days really are getting shorter now). It also shows the time spent in that 14V Peak range (in green), and the 13.5V "sustained" range (in blue).

You can see that on days after a trip when I hook the solar panel back up for the first time in a while, there’s a lot of green. That makes sense, as it has to recharge from the few days of running the battery down. As things recharge over the first day or two, you see the blue begin to dominate as it’s now just having to recharge the continuous draw. And given the size of this solar panel, I can also power my Netgear Nighthawk & the RVwhisper module directly from the engine battery.

Hope you find this useful!

So I bought an RV....

A few months back, Laura talked me into buying an old RV from a friend of ours. WE thought it would be a great way to get our elderly Mother-in-Law back home to Mississippi to visit relatives. It's been an interesting few months.
So the RV in question is a 1994 Fleetwood Bounder 34C. Chevrolet engine, 34 feet long, and almost entirely original. Original carpet, original wallpaper, original electrics. Needless to say, she's needed a lot of work. We've been taking it out regularly to work on it. So far we've replaced the flooring (some old stained carpet, switched out for vinyl flooring), replaced the wallpaper, repainted the cabinet, replaced the power inverter, replaced the water pump, replaced the awning, replaced the AC Compressor... It's been a big project.

Over the course of all this, it's been important to monitor all the variables of the RV and see if things are improved or getting worse. It didn't take long to stumble across a product called RV Whisper

The RV Whisper is a low power communication devices that runs a local webserver and low-power communication network that can talk to a wide variety of sensors. I bought some temperature sensors (to monitor the temp inside the RV, as well as the fridge and freezer to make sure they work), door open sensors (To work like an alarm for the front door, and to allow me to correlation temperature inside the RV to the opening of the door), and some battery sensors for both the Coach & Engine battery (the batteries were one of the first main problems we tackled).

The device generates a weak wifi network that you can connect to directly to monitor the device, or you can connect to a larger Wifi and the RVWhisper company offers (for a small annual payment) a reverse proxy from their website to your device. They don't store any of your data, which is nice. However, this also means that if you have an interruption in your network then you can't get any data.. Not even historical.

Me being me, I wanted something a bit more robust.. And while I'm at it, if I could get some more sophisticated visualization and analysis I might be able to get more information on what's going on inside the RV.

Introducting "RVWhisper Monitor", freely available on Github.

I'm running this at home on my Raspberry Pi. Every 30 minutes it pulls an hour of data (the overlap helps with small network problems) and stores it locally in SQLite databases. There are also a few scripts there to visualize the data as static HTML files uses Chart.js for some basic interactivity. Check out an example here.

Once the data is stored locally, I can start calculating some more advanced visualizations. The most important one I've come up with so far is the Battery analysis visualizations that show the slope of the battery state, as well as things like min/max/average over select periods (daily). You can see some of those visualizations here.

I'm still working on it. It's been a great help so far, particularly since I'm forced to park my RV at a storage lot a few miles away from home. With the help of a decent solar panel to charge up the engine battery I can keep the Nighthawk modem and RVWhisper unit powered, and then monitor it from the comfort of my house between visits.

If you have any ideas or recommendations, don't hesitate to let me know!

More Audiobook Recommendations

I’m really enjoying audible so far. Between the one credit per month that comes with the subscription, and the 2 free Audible originals you get each month, I find myself having no problem keeping myself busy in the commute.. So i thought I would share some of what I’ve been listening to lately:

  • Feathers & Fire series: Books 1 -3 - Just finished book 1 this morning.. If you like Supernatural or Constantine, you’ll enjoy this.
  • The Institute by Stephen King - It’s Stephen King, need I say more?
  • Carnival Row: Tangle in the Dark - I’m told it’s a prequel to the new Amazon Prime show.. It was interesting, albeit a bit of an unsatisfying conclusion (presumably to lead you into the show)
  • The Home Front: Life in America during WW2 - Podcast documentary on the untold stories of life back home in the US during WW2. Lots of interesting insights, complete with real interviews and recordings make both recently and during WW2.
  • Mystic School of Musicraft - a Harry Potter-esque story of a girl who discovers she can do magic and joins a prestigious school after the untimely and mysterious demise of her parents. A bit young-adult, but fun and actually includes the corresponding music in the background.
  • The Adventures of Tom Stranger and A Murder of Manatees - a hilarious pair of books narrated by Firefly’s own Jayne Adam Baldwin, in the vein of Hitchhiker’s Guide to the Galaxy.
  • The Singularity Trap - SciFi story about a mining group that stumbles upon the secrets of an ancient alien race
  • The Man who Knew the Way to the Moon - The real life story of John Houbolt, one of the minds behind the first successful moon landing.
  • Every Tool’s a Hammer - Adam Savage’s rules of creativity
  • The Dispatcher - a short SciFi story about a world where Murder becomes impossible as people just "re-awaken" in their home when they meet untimely ends, and the loophole.

The Antidote: Happiness for People Who Can't Stand Positive Thinking

Just wrapped up another Audiobook, this time it’s "The Antidote: Happiness for People Who Can’t Stand Positive Thinking". It’s a 6-hour and change book written and narrated by Oliver Burkeman, who has lots of similar books.

In short, it’s a book about the trappings of the "Cult of Positive Thinking" and references lots of psychological studies that demonstrate that Positive Thinking can actually make us less happy, because things rarely turn out as happy as we can imagine. Instead, he proposes a moderate amount of negative thinking, imagining just how bad things can get, which can then make you a bit more relieved when you realize that basically never happens. Along the way he links this to the ancient teachings of the stoics, buddha, and various other religions.

It’s an interesting listen, and makes reference to Ernest Becker’s The Denial of Death, just like "The Subtle Art of Not Giving a F*ck".

I enjoyed the first half of it. The latter half gets a bit slow, since it’s mostly more evidence for reinforcing the first half, so it felt a bit repetitive and dry.


Every day I have about 30-45 minutes to drive to work, and another 30-45 minutes to drive home. That means an hour or more of drive time every day. I’ve had a Spotify account for a long time, but after a while the playlists got boring and stale. I tried podcasts for a bit but beyond a few episodes of Hardcore History (Thanks John for the tip!) , I couldn’t find much I liked.

Late in 2018 I setup an Audible account. Started with the usual free trial and converted after a while. So far I’ve finished the following books:

I’ve heard about Audible for years, constantly peddled via Youtube starts and other Podcasts. I never really thought it was worth it, but having used it for a few months I finally get it. It’s a delicate balance: Finding books interesting enough that you don’t go to sleep, but not so interesting that you wind up sitting in the parking lot waiting for a good place to stop, and not so complex that the few seconds of highway-hypnosis zone-out doesn’t completely trash it. (I wouldn’t recommend doing Lord of the Rings via Audible, for example).

So self-help and management books have so far been a great match (as evidenced from the list above). The new "Audible Originals" program is great too, since I only get 1 free book a month. With the Original’s program, they pick 5 or 6 items every month and you can get 2 of them for free (that’s how I got The Last Days of August and Victorian Secrets).

What’s fascinating is I find something magic happens in your brain afterwards. For example, "The Five Dysfunctions of a Team" is the story of a new CEO stepping into a floundering company, and the various interactions with the C-suite team she inherits. The entire book is read by Charles Stransky. However, looking back on it I have memories of distinct voices for each character. I’m honestly not sure how it happened, but the same way you wind up with mental images and mannerisms for characters in your own imagination when you read, the exact same thing happens here.

So In short, I recommend it. It’s a great way to pass otherwise unusable time, and broaden your perspective at the same time with some good reading. If you know of any other books I should put on my wishlist, post them in the comments below!

Netgear R7000N Nighthawk: A later opinion..

So I’ve had the R7000N for about a month now. It’s a pretty good router, but it has some problems. Sadly, they’re the same problems I dealt with constantly on routers prior to my Airport.

The biggest one is 2.4Ghz Reliability. The 5Ghz band is rock solid. The wired ethernet is rock solid. The 2.4Ghz band comes and goes on a regular basis, for no good reason I can find. At first glance you think “Well just use the 2.4Ghz", but it’s not so simple. Ring doorbell, Kuna light, Nucleus Tablets, Echo Dot, wifi-enabled clock/weather station… All of those are 2.4Ghz only.

Apparently this is not a new problem, there are long threads on their support forums for it. I tried a few of the usual things to no avail, but eventually stumbled upon the following combination of things:
  • Upgrade to the new Firmware ( V1.3.1.44_10.1.23 )
  • Disable automatic channel select, just set channel 11
  • Reduce the speed from 600Mbps to 289Mbps
  • Check “Disable Port Scan and DoS Protection"
This combination seems to have fixed it. That last one was a bit disappointing (It means my router is now wide open to port scanning), but it works.

I remember running into similar problem all the time, where the 2.4Ghz would die .. I usually attributed it to overheating or traffic, as it would usually happen when I would sustain a lot of bandwidth for a while. Either BitTorrent of a particularly active torrent (hence a bunch of traffic), or streaming Netflix or Youtube for a long time.

I post this here in hopes that it helps someone else. I’m disappointed that a new $200 router in the year 2018 suffers from the same problems plaguing cheapo routers in 2005, but I guess I shouldn’t be surprised.

Netgear R7000N Nighthawk

For the last 10 years, almost exactly, I’ve been using an old 2nd generation AirPort Extreme wireless router. It’s been a fantastic piece of kit. I’ve never had to reboot it from getting confused, it’s worked with dozens of clients and multiple configurations as I’ve changed service providers, iPhones, added and removed network extensions, and more. But after 10 years, and moving into a modern home in South Florida where they use metal studs for the exterior surfaces, some problems have shown up.

Perhaps the biggest problem has been range. Even in our old home, being on the farthest extents of the house meant spotty coverage. In our new home, I can be only 30 or 40 feet away and have trouble getting signal. All of the pipes and metal studs cause worlds of interference. And with the new exterior items I’ve been adding to our network (wifi security cameras, ring doorbells, wifi-enabled garage door openers, etc) I’ve been forced to play games with cheap and flakey wifi extenders. It was finally, after 10 years, time for an upgrade.

After consulting with some friends and reading some reviews, I finally settled on the Netgear R7000N Nighthawk .

The following was important for me:
  • Easy configurability - This has the usual web page, but also an iPhone app that can be (and was) used fully for setup of the device.
  • Long Range and multiple bands - N on 2.4 and 5Ghz, and lots of broadcast power.
  • Multiple ethernet ports - I want my xbox, PS4, and desktop all on wired ethernet.

I’ve only had it up and running for 24 hours, but so far it’s working great. I configured it with the same SSID and password as our existing network, so all of the laptops and iPhones came through without an issue. However, I did have a few glitches to fix:
  • Kuna Toucan Camera - this I had to reconfigure to the new network. Partly my own fault, since the Wifi-extender I was using wouldn’t auto-reconnect to the network, but now I don’t need it! The Toucan now talks directly to the primary router.
  • Ring Doorbell - It failed to auto reconnect, sadly. I tried and failed to manually reconnect this per their instructions, and that never worked either. I wound up power cycling the doorbell (hold the button for 5s to turn it on, press to turn it on) and it worked first time.
  • Vonage & Airport Express - I had an old Airport Express configured as a wireless client to where my Vonage Base station sits. This failed to reconnect (as expected, Apple does some shady stuff inside their own ecosystem). I had to factory reset it to get it back to default, then I could configure it as a Wireless client to the new network. Now it works great!

So I’ll update as time goes by. So far it’s working great. It even has some features I’m still discovering:
  • Integration with "Disney Circle". Some kind of fancy Parental Control app. I haven’t dug into this yet.
  • Bandwidth Monitoring - This will be a great feature, to see how much bandwidth we’re actually using day by day.
  • Remote Monitoring - I haven’t gotten comfortable enough to turn this on yet, but apparently you can enable access to the iPhone app anywhere in the world. This might be useful if I turn on the parental control features, but for not I’m not messing with it.
  • Quality of Service (QoS) - Again, I haven’t played with this yet. I think I can use this to prioritize bandwidth to our AppleTV’s for better Netflix and such, but honestly I’ve never need that before. But if I do, I know where to go.

Remarkable Tablet

A few months ago I saw an ad on Facebook for something called the “Remarkable Tablet".

Looked impressive. I’ve tried various iPad note taking apps over the years, most successfully Notes Plus. Unfortunately, all of the capacitive styluses I tried had lackluster accuracy. It seems like a really obvious thing, to take notes on a digital tablet, but the iPad never quite fit the bill. App developers had some clever tricks, like how NotesPlus does it’s zoomed-in text entry bar, that works pretty well.

However, for me at least, the real “power" of physical note-taking is in the freedom of it all. I can draw stars and lightbulbs in the margins, I can put boxes around text for emphasis, I can draw a big line and arrow connecting two separate paragraphs of text when the conversations pulls a “getting back to the original topic". Sure I can usually do that on iPad apps, but it’s a weird combination of switching tools and modes each time, breaking the flow.

After 2 months of using my Remarkable tablet, all I can say is WOW. They got it right. You create a notebook, select your type of pen (gel, pencil, or fountain) and off you go. It’s as simple as that. The texture feels like real paper, it’s an e-ink display so it looks like real paper, and the response of the pen against the tablet acts like real paper.

I’ve replaced carrying my laptop to meetings and using Evernote for notes-taking, and now I just use this. It’s a fraction of the size and weight, and it’s actually faster to use. I can email the resulting notes to my Evernote Email address as PNG’s, and then Evernote takes care of the rest.

  • Feels and acts like real-paper
  • E-ink display gives amazing battery life (although you need the latest firmware to really get this) and makes it look like paper
  • Easy to connect to wifi and email your notes off-device

  • A bit pricey, $500-$600 brand new.
  • E-ink display means it can be a bit slow sometimes navigating menus.
  • Single color - But let’s be honest, how many people really carry around a collection of pens to take notes in multiple colors.

The software is still under active development, as evidenced by this great new firmware update this week that rearranged the Template system solving one of my biggest complaints with the device. And to be fair, there are still some bugs in the system:
  • Exporting as PNG works pretty well, but a multi-page document I’ve seen many times arrive out-of-order in Evernote. Easy to fix tho.
  • Exporting as PDF I’ve found doesn’t work well at all. The resulting files are MASSIVE (multiple megs per page), and lots of artifacts. Typically erased content “reappears" in the PDF.
  • Documents with many pages (5+) I’ve seen start to exhibit artifacts on the tablet itself. Content from previous pages copying over, odd behavior. I’ve simply worked around this by creating multiple small documents, which works best for Evernote anyway.

Still, it’s quickly become one of my favorite tools and part of my standard workflow in the office.

I give this one a 4.5/5 Stars! I look forward to seeing what Remarkable does next!

New Hobby: Woodworking

For those of you watching my Instagram, Twitter, or Facebook pages you no doubt have already seem most of this.

Of the new hobbies I picked up right at the end of 2017 was Wood Working. Inspired by lots of you tubers and some ideas stuck in my head that I couldn’t find available anywhere else, I finally started collecting up some good tools and dove in. I started with some basic shop furniture and then into smaller things for inside, and then into some big pieces like the end tables and the mudroom rack.

I’m still learning a lot as I go, but I’m loving every minute of it.

Giving up on PGP (Kinda)

Yesterday I read a short piece on PGP from ArsTechnica’s Filippo Alsorda entitled “I’m throwing in the towel on PGP". It’s a great piece on the fact that PGP is still the pinnacle of security, but it’s just failed on everything around use-case and integration. Like him, I use PostBox for email, with EnigMail. I’ve maintained a set of keys for several years, regularly expiring and recreating them, but the only signed email I ever got was an annual notice from validating my domain.

Even doing everything half-right (I never did key-signing parties and all that), it still was mostly “security theater". The keys sat on my laptop hard drive, and I had no way to access them from my phone or tablet. Every time I wanted to expire my key or adjust the expiration to push it out another year, I had to resort to arcane gpg command lines cut-and-paste from StackOverflow. Odds are, I fubar’ed it more than once and I’m nowhere as secure as I thought.

So in short, I’m giving up on it. I’ll keep things enabled for a while, but I’m not going to bother maintaining it like I have. Instead, we have better tools these days. I’ve setup Signal for encrypted instant messaging, and setup a ProtonMail account for email.

So, if you want to reach me via an encrypted channel.. Reach out to me normally (Facebook, twitter DM, email, etc) and I’ll share the details.