I’m going through a rough period right now. There’s an illness in my family and I’m having a hard time focusing on anything but worrying and trying to take care of health stuff. Everyone is going to be okay, but it’s going to be a difficult four or five months, and I really appreciate your patience and understanding. I’m going to keep putting up comics, but I don’t how much else I’ll be able to work on.
To anyone I’ve been corresponding with, I’m sorry that I may be even more tardy than usual. While davean (the xkcd sysadmin/business manager) monitors the press@xkcd.com address, I know he only forwards to me a fraction of the huge flood of mail that goes there. If you’re trying to reach me personally about something, you can write to me directly at xkcd@xkcd.com, but I’m afraid I won’t able to reply to most of it right now.
I know there haven’t been any posts here in a while. Since most of my projects are on hold right now, I thought I’d share some pictures from one that’s almost done: an underwater ROV. Exploring lakes and oceans has always fascinated me, and while I’ve spent a lot of time snorkeling and free diving, in the end I’m more interested in sending robots than going myself.
I tried to build a couple of ROVs in high school out of scavenged R/C cars and spare parts, but none of them ever worked very well. Last summer, I got interested again and picked up an Inventivity ROV-in-a-Box:
It’s a very basic kit designed to use off-the-shelf parts as much as possible, to encourage people to play with the design or expand on it. I’ve gotten a lot of help and some cool ideas from the company founder, Dr. Karen Suhm, who coaches robotics teams in ROV-building competitions and generally knows everything about ROVs. The kit comes with a good set of underwater motors and a sensitive camera, and this summer I started modifying it to use an Arduino and joystick control, running the whole thing over Cat-5 cable (which significantly lightened the tether). This will also let me add other equipment, like a still camera, depth gauge, compass, and sonar.
It’s very close to being finished—I just have a couple wires to reroute and a leak to seal—but for now, here are some pictures from construction and testing:
I made a coupler so the tether could be detached, and added a chamber to hold the Arduino, Ethernet shield, and motor control board. A Python script on the surface translates joystick values into motor speeds, and the Arduino has some code to listen to commands via the Ethernet and control the motors using three TLE-5206 H-bridges. The 5206s offer more protection than some other H-bridges—I initially used some smaller chips, and managed to blow out a couple. (Thank you to mpanetta of #sparkfun for hooking me up with the 5206s.)
A note to anyone who wants to build something like this: the Arduino isn’t actually capable of processing video, so you’ll need to either put an Ethernet camera and hub on the rover, or—if your camera isn’t digital—do what I did and divert two of the Cat-5’s twisted pairs to carry RCA video, running the Ethernet solely on the other half.
My friend Mike loaned his canoe for depth testing in Walden Pond, which is (according to data from the 1940s) the deepest lake in Massachusetts
At the bottom of Walden, there are close to three extra atmospheres of pressure.
The zip ties double as binary depth markers. This one is 14 meters.
This is the vacuum pump for sealing up wires passing into the sub (it’s sitting atop a draft of the online communities map). If you open up the exterior/water side of a cable and submerse it in a pool of marine epoxy, then apply suction to the dry interior of the sub, it sucks the epoxy through the cable, plugging it up completely. You can also use it to suck all the air out of a wine bottle with random objects inside. It’s fun to see how different materials react to a near-vacuum—particularly if you’ve just drunk a bottle of wine. I didn’t get much more done that day.
Lastly, here’s a clip of the bottom of Walden Pond, about 80 feet below the surface. This was an unpowered pressure test—the sub was just dangling on a rope—so it’s not very exciting, but it was the only test where I could record the video feed:
The Walden lakebed is pretty dead—the material you’re seeing is flakes of debris stirred up by the sub. In other lakes, we’ve found cooler stuff. In Seymour Pond on Cape Cod, we had huge catfish fish swim up to the camera and look at it, and we explored a sunken fishing boat on the bottom of Sheep Pond. I’ve also learned that deck chairs apparently fall off docks all the time—the lakebed 20 feet below the dock on one lake was absolutely littered with them. When I get a chance to send it to some more interesting places, I’ll be sure to share footage.
P.S. A belated thank-you to the NYC Makerbotters; after I posted comic #743, they fabricated and mailed to me an actual tiny open-source violin.
xkcd 
I’m going through a rough time with a family member’s medical situation, too, and I’m understanding how much it consumes a person’s energy. I can do my job for hours and not be nearly as exhausted as I am researching my sister’s situatoin or sitting with her during treatment for only a short time. Please let your priorities change however they need to, and be gentle with yourself.
All my best to your family and to you.
LikeLike
The wonderful thing about the internet is if you hold off on finishing a project, someone else will do the exact same thing and blog about it, saving you all the mistakes you would have made.
I look forward to hearing more about your arduino ROV.
LikeLike
Sorry about the family troubles… wish you the best, and if you need to take time off from the comic then do so.
Nice ROV, though (clever uses of CAT5 and zip ties indeed!), and that video was really relaxing to watch while listening to this http://www.youtube.com/watch?v=gHRvw-XqF_k (Siesta Del Sol by In Credo).
LikeLike
Glad some folks liked the quote. Maybe y’all will take it easier on us liberal arts majors 😉
I love this damn comic, and the blog too. Be well Mr. Munroe.
LikeLike
Velociraptor Cloaca is a poopy-head because I am very real, and Pokan is an idiot because I am very much alive. -___-
Who else would Randy base his incredibly creepy comics about a woman stripping in a TGIF on?
LikeLike
Good luck to you and your family.
LikeLike
Wishing you well! Thanks for bringing some joy to my life every Monday, Wednesday, and Friday – I know whenever I’m going through something rough, looking through past comics always helps me feel better. But I guess that might be harder for you to do, since they’re yours and that might be weird. I don’t know.
Anyway, my normal approach might be useless here, but I’ll keep your family in my prayers.
If all else fails, I suggest filling your room with playpen balls. You have no idea how tempting that is.
❤ Kelly
LikeLike
The best comic I follow and the most inspiring I met, sincerely I hope your family and you get better, damn! why bad things happen to good people?
LikeLike
Thank you for many years of wonderment and pure, unadulterated geeky awesomeness. And an awesome sword-fighting, code-compiling t-shirt. Family comes first, do what you gotta do, and if there’s anything that we could possibly help with please don’t be afraid to ask, there’ll be a flash-mob at your beck ‘n call at a moments notice 🙂
LikeLike
Mate,
Wishing you and your family all the best.
Your comics, humour and ability to shine a light on the bizarre, interesting, and quaintly beautiful things in life have lifted my spirits on many occasions.
I truly hope you and your family have reason to have high spirits again soon.
– Richard
LikeLike
I’m really sorry to hear you’re going through a tough time right now. I’ve been there, and I understand how it can be. I wish I had some game to send you! But I am sending you my best wishes and hopes that whatever happens is always for the best.
I’ve enjoyed your comics for quite some time – you seem to have a window into my life I think 🙂 I’ll be glad to read more when you’re able. Until then, take care of yourself and your family – I think it’s safe to say we’ll be here when you’re ready 😀
Kriselda
LikeLike
I’ve had illness had derail my family’s plans… We can’t control everything. We can only care for one another while we are here.
Best wishes to you and your family!
LikeLike
Good luck to you and your family. We all love what you do and we’re grateful for all of the laughs.
It’s really interesting to see the bottom of Walden pond – for all the times I’ve been swimming there, it’s a completely new perspective on it.
You should try Clay Pit Pond in front of Belmont High School – legend says there’s circa-1900 construction equipment at the bottom, back from when it was an actual clay pit.
take care.
LikeLike
Dear xkcd,
I am sorry to hear about your family troubles. You have become a indispensable part of my internet experience and I wish everything turns our fine for you and your family.
Othon M. Moreno
LikeLike
I enjoy XKCD, it brings a smile, laugh, guffaw, nearly a literal ROFL, and sometimes puzzlement to my week!
However, my thoughts are with you and your family. You do what you need to take care of family and yourself, we’ll be here.
P.S. I love the ROV!
LikeLike
Thanks for all the comics over the years! Sorry to hear about the rough times, hopefully they will go by smoothly and soon.
LikeLike
You and yours have my thoughts. I hope everything turns out okay.
Don’t force any xkcdness if it’s not in ya to do it. All of your readers/fans would rather you take care of you.
LikeLike
What everybody else said. Your work is a bright spot in the slog, and all us slogging out here know that how hard it is to just make it through to day, let alone to light that li’l spark.
Please, do whatever you need to do, know that we’re all hoping the best for you, and whenever it is possible to come back, we’ll be happy to see you.
b
LikeLike
Heya guy! Caught your chess game at first ROFLCON, and just wanted to say stay froody, like you could be anything else!
LikeLike
I’m very sorry to hear about the illness. Best wishes to you and your family. And no worries about the comic.
LikeLike
/trite
I’ll pray for you and your fam.
/end_trite 😛
For serious.
LikeLike
I’m so sorry to hear about you family illness. Please accept this anonymous wish of health and fortune for you and your family.
Be well, friend.
LikeLike
Wishing you and your family all the best, Randall. I’m sorry to hear about the illness–I hope things get better soon.
Cheers,
C. Panda
LikeLike
Randall Munroe,
You’ve given us loads of joy every M/W/F. May it be well for you and your family.
I digg the ROV! 🙂
LikeLike
Wishing you the best.
LikeLike
As a rule of thumb, I’m a lurker, not a commenter, except when something really matters. And this does.
I will pray for you and your family. May everything resolve favorably and quickly.
LikeLike
>>why bad things happen to good people?
Because they happen to everybody. Doesn’t make it suck any less, to be sure. Hang in there, Randall.
LikeLike
In the department of finding interesting things in ponds: as an active fisherman, if you want to see fish look for some kind of structure (rocks along shore, trees that have fallen in, places where there’s a big change in water depth over a short distance, vegetation, etc) instead of looking at random patches of bottom.
LikeLike
Following the lead of other lurkers, I, too offer my condolences. I hope that it isn’t something life-threatening, and if it is I hope that your family can beat it. Heck, I hope you beat it even if it isn’t, but you know what I mean.
Best of luck.
LikeLike
If, for this or future projects, you want to do more with your onboard controller (ie process video), check these out: http://leaflabs.com/
I adore your comic and have for many years. You are wonderful. Thank you 🙂
LikeLike
Best of luck through troubled times! We’ll all still be here when you get back.
Wishing all the best of health to you and your family,
L.
LikeLike
@MattH That’s definitely Thoreau’s Walden, not the one near Lynne, as Thoreau’s Walden is the deep one. I went there many times in college and recognize where the photos were taken.
@Randal: If you weren’t aware of the Thoreau connection, then this post is astoundingly serendipitous. I think (putting on my prof hat), you’d really enjoy Walden. Thoreau, too, was working between science and culture, nature and the self. And he excelled at saying big things in a short format — epigrams and paragraphs that spin out into constellations. Not unlike the artistry of some rather excellent cartoons we all know and love.
All lakes, be they of water or grief, have bottoms. Sometimes we can send an ROV, sometimes we have to go ourselves. Courage.
LikeLike
I don’t know if you’re familiar with Analog Devices’ accelerometers (arduino seems to go for other parts), but thought you might get a kick out of http://iabervon.org/~barkalow/advi430.html, which I came up with when I was using the ADXL330. Analog Devices’ parts aren’t open source hardware, but they do document the heck out of using their components, so they’re nice to write drivers for.
LikeLike
I’m long time reader of your comic, first time commenter.
I’m sorry to hear about your hardships and wish you the best. Hang in there! I’ll be sending the best of wishes.
LikeLike
I wish you all the best. With joy I am following your all your work. Take all the time you need, you deserve it.
LikeLike
I’m sure all of us who read your comics and the blog will hang around until things are under control. Don’t push yourself needlessly. Emergencies takes alot out of you in any aspect of your life. Take care of yourself and yours!
LikeLike
I love your work and wish you well.
LikeLike
take care, and take all the time that you need, we’ll wait (even from Italy 🙂
LikeLike
Had no idea about the trouble until todays comic. I hope everything comes out well for you, your comic has been updated strongly, and even if it wasn’t family comes first. Good luck, me and many others await your comeback.
LikeLike
Your lovely comic makes my week.
Take Care!!
❤
LikeLike
… GET OUT OF MY HEAD, RANDALL!
Seriously, I’m in the planning and design stages of creating a small-ish ROV with CAT-5 as the control line.
LikeLike
Family goes first. Take care.
/Per
PS: I love the binary depth markers.
LikeLike
Here we’re a few people crossing our fingers for your family issue. We wish you all the best in those difficult times.
❤
LikeLike
Hello Randal.
I don’t know how else to get in touch with you. Just saw the latest comic. Very concerned. Hope it all turns out well for you. My bestest wishes. Your comic and blog bring so much joy to so many people but when you are in need, we all can do little. Infact all we can do is wish best for you.
Thank you for everything. Hope you feel great soon and things go your way.
LikeLike
Best wishes to you and your family!
LikeLike
❤
Take all the time you need.
We'll always be here.
LikeLike
You’ve helped my brain process some amazing things over the years; I feel like there should be something I can do in return. Then again, maybe I’m overthinking things.
Take care, man. Be well.
LikeLike
I wish your family member a speedy recovery.
LikeLike
Randall, take your time and relax. We love you and please don’t feel any pressure to hurry back. I hope your issues work out.
LikeLike
Dear Mr. Munroe! We really appreciate you and we wish you all best, and if you need, please, take 26 hours in a day. We`ll be waiting and crossing fingers for you!
Loving XKCD in Russia =)
LikeLike