Freesteel Blog » Weekends
Well, the hang-gliding has been quite lovely. But the logger appears shot to pieces.
I still don’t know what I am doing when I get to cloud-base, which is probably why I plummeted out of the sky shortly after this picture was taken.
As soon as I took off, the barometer stopped communicating most of its data.
This is the device I lavished so much time on isolating it from the rest of the electrical circuit and arranging for it to bitbash the information back through an interrupt pin.
It could be some timing issue, or whatnot. No way to debug it. Luckily I got myself a Bluefly vario which does the same thing of reading a MS5611 barometer on a tight 50Hz loop and transmitting it back to the main board. In the Bluefly’s case it’s for the purpose of running a Kobo/XCsoar system. I’ve just given up on the one I built as it’s too inferior to simply running XCSoar on the phone where I’ve got colour and more or less know how to use it.
Luckily the Bluefly also sports a GPS and works through a serial port, so I’ve yanked off the Adafruit GPS breakout board and bodged the wires to insert the Bluefly in its place.
Then there was a small matter coding it up using a complex state machine to program the GPS module through the Bluefly pic processor to get it to read at 10 times a second.
But then the BNO055 orientation sensor played up and decides to shutdown at unexplained moments for unexplained periods of time.
The white vertical lines are 10 minute intervals, and there is a green dot for every successful orientation reading, with y-value proportional to the time since the previous reading, so I’m getting gaps in the data of half an hour in flight.
I’ve produced a reset timer to try and start it off again if no data comes through for 20 seconds.
Anyways, here is one of those nerve-wracking close encounters with the ground during the flight.
Tuesday, April 19th, 2016 at 11:29 am - Hang-glide
If you look closely you can see the grin behind the helmet.
There was nothing especially epic about this XC flight from the Long Mynd to Clee Hill, except a masterful get-away from the slope in nil-wind with just one thermal during which I miraculously stayed on top of all the paragliders. Also there was a very low-save.
I took off at about 1:30 during the period when the wind was less than 5mph and sometimes coming from the SW. This trace is off the Long Mynd Gliding Club weather station:
No one could explain why there was so little breeze to make reliable ridge soaring possible. Meanwhile, there were champion pilots flying 100s of miles on seven hour flights on that day, which one must try not to feel bad about, when I “only” managed to stay up for an hour and a half.
One thing I did learn for sure is that I utterly depend on the thermal assist of the XCSoar running on my android phone. (That Kobo kit you see in the video is going in the bin.) The magic went away when the phone ran out of batteries; my thermal tracking abilities went out the window from that moment on. So this flight (and hopefully many more, when I sort out an extra power supply brick for the phone) is dedicated to Lines 145 to 202 of XCSoar/src/Renderer/TrailRenderer.cpp which was able to direct my search for lift whenever I lost it. This is the section of the manual describing the critical feature:
A couple more regrets. I didn’t make cloudbase by at least 300m, according to the dew point measurements. And the barometric reader, based on bit-bashing and interrupts, is completely shot to pieces by the overload on the microcontroller from acquiring so many other inputs of data. Only about 1% of the readings are getting through. I’ve got to come up with some other answer, and I don’t have a lot of time in a week when we’ve got some help doing something about the state of the kitchen floor.
Wednesday, April 13th, 2016 at 12:39 pm - Hang-glide
Thought I’d scan and upload my article about flying in Austria for folks to download:
It happened towards the end of the flight before last when my wings became my own, and I just wasn’t thinking about it any more. I stopped having those intervals where I lose concentration and fall out of the sky because there was no concentration to lose. It was all about the feeling.
Above the town of Teba watching the cars scooting along the grid of streets like busy beetles in a rotten log
Low on same rocky hill just after take-off where I struggled to survive for some minutes before I found a bubble of rising air
If you need to learn hang-glide, there’s a English school down here called Lejair where you could get it all done in two weeks (instead of the average two years of weekends back in England) because the weather is better and they use tow trucks with gliders tethered above a trailer so you can learn how to fly it without having to run up and down the hill and learn how to steer in short difficult bursts. (If you have to ask why you need to learn hang-gliding, then you don’t need to.)
We were woken by all this nice birdsound. Then we spotted that it was from three tiny birdcages in the courtyard below and it seemed so cruel. Why can’t they use little speakers tuned to a radio channel that broadcasts live birdsound?
Got to go now. We’ve not had an off-day where I can devote 10 straight hours to coding the datalogger analysis or write any of it up. I have two interesting results to report. One being the delay on the GPS, and the second being the clean mathematical relationship between the turning circle and bank angle as measure.
Wednesday, March 23rd, 2016 at 11:19 am - Kayak Dive
I really have been neglecting to blog. I’m going to bang out a few quick posts on this the day before my holiday.
Saturday 12 March involved a grumpy day paddling around Hilbre Island with a rather fuzzy camera.
This is the stone wall on the northwest corner of the island at high water:
The professor on the water had just gone on a 10 day trip to Japan to use up an academic travel budget, and at the same time busted a chunk out of the dwindling global carbon budget [podcast here]. You don’t want to see what the bailiffs do when they collect on an unpaid carbon debt. They’ll take your food.
I’ve been speculating about a specialization of my Question from Hell proposal where visiting professors who have just flown to give a lecture get routinely asked about their carbon budget (which they could have avoided by teleconferencing) as the first audience question from a young student. It will be rude and ungrateful to ask such questions of a visiting guest, and will embarrass everybody. The excuses are lame.
The top excuse will be: “We don’t have the equipment”.
If that one gets a lot of laughter, the second excuse will be: “Meeting in person makes a big difference”. To which I’d like to respond: “Where’s the research?”
There isn’t any.
I’d love to set up a controlled experiment where the person who doesn’t do the 10 day trip to Japan gets to take a 24 hour bus ride to a hotel opposite a Japanese takeaway in Dundee via Plymouth and is locked-in with the internet where his only communications portal for the next 120 hours is a telepresence robot parked in the corner of the lab in Japan. He is free to rove the corridors if he’s being ignored. Maybe one of the brighter students would take pity on the robot and take it home overnight for late night chat with bottle of sake, or even for a night tour round the city on a motorbike. I hear these VR goggles and hi-def cameras are pretty good these days.
The time duration exposure, the portability, and the lessening of inhibitions could easily mean that human bonds and interaction could be much enhanced compared to proceeding to these places as a meat embodiment that smells and needs to go to the toilet occasionally.
If this Questioning takes off I am expecting that university administrators, who can be blindingly stupid, commit to ban such questions, as you cannot ban something like this without actually telling people what it is you are banning.
PS. Cory Doctorow was burning up the planet ten years ago.
Wednesday, February 24th, 2016 at 9:59 am - Hang-glide
Work interrupted by a couple of mid-week trips, first to Long Mynd:
Then to Llangollen, where I didn’t fly so well and spent the entire time getting buzzed by this huge dual hang-glider that seemed always able to keep up with me.
That’s why you’re supposed to learn a lot by flying with really good pilots so you can see exactly why you’re not anything special at any time.
And anyway, the data logger was bust with a loose wire on the I2C connection. I should have enough data from the Long Mynd flight that I ought to be doing stuff with this morning. Instead I’ll probably work on the serial connection to the orientation sensor or do some on-line shopping for other electronic gadgets whose data streams I record and ignore.
Record and ignore
Remember the rule: the further removed in time and place is the data, the lower its value. While some data becomes relevant when it gets old, it’s as rare as antique furniture. You can count on the crap rotting in your garage not being within that category. The conclusion is if you don’t find an application for the data now, you’re not going to find it later on.
Following a very grumpy Friday and an off-the-cuff comment by someone on Facebook to the Wrynose Pass as a potential easterly site, I headed off from Bull Pot Farm into the Lake District where I have never been before.
I was not in the most ideal mood for this sort of thing, being alone with a hang-glider on an unfamiliar craggy hill at 3degreesC and 27mph wind. Fortunately I stopped myself from doing anything really stupid, and sat in the car stewing and programming until suddenly and unexpectedly the wind dropped to something between too light and perfect.
I didn’t hang around, having already scouted for my hillock of a take-off point.
Monday, October 5th, 2015 at 7:18 pm - Kayak Dive
Not much bloggable recently. Some well-formed untested ideas on matters of servo motor control, and lots of bad psychology. Two discoveries of note that’ll take up a lot of time are jscut for CAM and chilipeppr for CNC downloads, both of which run in the browser. I have an interest in this approach, but now that I’ve found some people who are doing it effectively, it will save me a lot of time.
Meantime, here’s a couple of bad pictures from a cheeky kayak dive in the docks during Becka’s Thursday night canoe polo session (aka murderball).
Getting ready to go down:
One of the scary eels that made me shriek when it appeared in the dark.
Eels look and move a lot like snakes. We’ve got an instinctive fear when we encounter them in their own environment. It was interesting how they could swim backwards just as easily as forwards.
Monday, September 7th, 2015 at 10:55 am - Kayak Dive
Home at last. Lots of stuff to do, so here’s just the bare facts of the trip to the north part of Ireland with our kayaks, as well as a 4-day booking with aquaholics where the weather blew northerly gales the whole time, which denied access to the famous north face of Rathlin Island and the basking sharks were a no-show.
|Date||Site||Place||type||depth (m)||time (mins)|
|2015-08-30||Gloster Rock||Malin Beg||Kayak||20||12|
|2015-08-30||Shark Rock||Malin Beg||Kayak||20||30|
|2015-08-31||2nd Pinnacle||Slieve League||Kayak||18||12|
|2015-08-31||Big Cave||Slieve League||Kayak||9||15|
|2015-08-31||Carrigan Head||Slieve League||Kayak||20||23|
|2015-09-01||Portnagh Rock||St Johns Point||Shore||26||52|
|2015-09-01||Skuddagh Rock||St Johns Point||Shore||17||48|
|2015-09-02||Black rocks||Rahlin Island||Boat||31||36|
|2015-09-02||HMS Drake||Rahlin Island||Boat||18||46|
|2015-09-03||Black rocks||Rahlin Island||Boat||31||38|
|2015-09-03||Scallop bed||Rahlin Island||Boat||21||48|
|2015-09-04||SS Lough Garry||Rahlin Island||Boat||30||29|
|2015-09-05||SS Lough Garry||Rahlin Island||Boat||29||29|
|2015-09-05||Black rocks||Rahlin Island||Boat||29||36|
|2015-09-06||Lees Inner Wreck||Strangford Lough||Kayak||11||24|
|2015-09-06||Lees Outer Wreck||Strangford Lough||Kayak||12||29|
Kayak diving wins again!
The most notable sighting of wildlife was this unexplained swimming snail above the kelp at the start of yet another black rocks dive (where we failed to find the right bit as usual).
Wednesday, September 2nd, 2015 at 9:17 pm - Kayak Dive
The past five days have been kayak diving and camping in Donegal. Now we’re in Ballycastle for four more days of expensive boat diving where the weather has turned bad and probably won’t be so good underwater, but at least we’ve got a roof over our heads.
Camping in Ireland seems pretty easy. The two places we’ve stayed at had “day rooms” for people with tents where you can do your cooking, make toast, sit down and drink tea.
First two days were at Downings, diving in the almost totally enclosed Broadwater Bay at Massmount, and then at the totally exposed Melmore Head once we’d got our confidence back.
Then it was south to pitch tent at Derrylahan hostel before spending the day out at Malin Beg having to seal launch the kayaks off the slip at very low tide and poking our noses along the Slieve League cliffs for a couple of kilometres to check if paddling its full length was going to be a silly plan. The local fishermen thought it was an okay idea and said there weren’t any currents. With a northerly wind blowing we had perfect shelter.
Here’s a short video of a dive into a shoal of mackerel at the mouth of a huge cave. I noticed them only because they broke the surface as the streamed past my canoe and it looked like rain was falling onto the water even though the cavern ceiling was dry.
The next dive onwards was on the east side at exactly the tip of Carrigan Head, completely sheltered from the wind, waves and current by a 2 metre high headland of rock, but where the sounder registered a sudden dropoff to 20metres. The place was scoured of kelp revealing a low animal turf and dozens of large wrasse fish parked in the slot doing nothing in particular. As usual, Becka did the cycle back along the road to fetch the car while I packed the gear and walked up the road to the hostel to have a cup of tea.
On our fifth day in Ireland we got air fills at Dive Donegal before using it all up on two long short dives from St Johns Point. If anyone is counting, the one on the left out from Portnagh Rock should be in the top ten shore dives of the world for its perfectly designed architecture of satisfaction. You use up your air at the perfect rate at the perfect depth and everything is easy to find. The karst rock of the main reef has eroded into shelves that are like a condominium hotel for critters (one alcove contained a fat lobster chewing on the hide of a dead dogfish). It’s worth the drive, even if we couldn’t find a decent breakfast anywhere nearby to fill us up in the morning.
All this kayaking is exhausting and makes me not interested in spending many hours at the computer. I’ve got all winter to do this when I get home and settled down.