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Posted by Jack Crossfire | Jul 21, 2009 @ 12:05 PM | 4,952 Views
India is going to make July 20 a national holiday. That's right kids. The Apollo program is that important to them. They all worked on aerospace & only came here to work on cat mortgaging software because of the free houses.

US won't make the moon landing a holiday obviously, but it may make October 4, 2018 a national holiday. That's when universal healthcare gets bailed out.

Now a repeat of our Apollo videos 4 those of U who didn't get the memo.

neil armstrong reborn (2 min 57 sec)

NASA said these were restored segments from the 1969 broadcast, but we can't see any difference compared to the other Goo Tube uploads.

1:10 Scale Saturn V with stabilization (1 min 36 sec)
...Continue Reading
Posted by Jack Crossfire | Jul 18, 2009 @ 01:32 AM | 5,064 Views
The answer is no. U can't drive a 915Mhz front end using a USART. U can't change clock polarity as required for fake full duplex. So even with a dirt cheap, bare front end, the options for 915Mhz R expensive & more expensive.

Radio breakout boards would now be the same size, have the same hardware & cost as much as completely new autopilot boards. Having the radio on the same board as the autopilot would greatly increase bandwidth. Switching between 2.4Ghz & 915Mhz would involve switching the entire autopilot. U can devote the accelerometer & magnetometer pins to the radio.

Groundstation is probably better off with a breakout board, but want to maximize the bandwidth.

There R now a bunch of processors which can probably make spin copter a reality & greatly reduce the cost of a VikaCopter.

915Mhz Vika1 airframe:
PIC18F23K20 28 pin $2.40

915Mhz Vika2 & Vika3 airframe:
PIC18F13K50 20 pin $2.42

915Mhz groundstation with sonar:
PIC18F14K50 768 bytes RAM $2.66

Everything U order has to come with backups, so the $9 in Vika 1 really killed us.

But U don't know if 915Mhz will work with GPS & the Walmart video transmitter. It may be a complete disaster, which has U leaning towards another basic, through hole test setup.
Posted by Jack Crossfire | Jul 17, 2009 @ 04:53 AM | 4,830 Views
So U think you're going to be the last American when everyone flees to China.

You're going to have all the roads to yourself & drive around at 200mph. You're going to loot all the stores & make yourself a solar powered Winnebego.

But realistically, all the stores in US sell are mortgages. Forget about any electronic parts without global shipping & who's going to bother shipping to 1 person? The roads are going to disintegrate long before U get your fling. So who is captain America gonna be?

The last American is probably going to be someone who never did anything they were told, never got a PhD, saw themself as their own provider, saved gold instead of dollars, avoided professional advancement, never got a Palm Pilot/iPod/Razr/iPhone/gPhone/netbook, knows how to vacuum pack food in glass jars & make their own fry sauce.
Posted by Jack Crossfire | Jul 16, 2009 @ 02:25 AM | 5,055 Views
It was sunny in Fl*rida but raining foam in the upper atmosphere.

Shedding on sts-127 (0 min 18 sec)

We expected the 6 tank refills to make quite a shedding & sure enough, the tank shed like a snowstorm. NASA predictably insisted foam shedding was not a problem, the debris looked doubled because of shadows, & it only caused small scuffs.

The voters predictably did exactly what they were told & shut up.

Oh yeah. NASA tested it to 6 thermal cycles without seeing any shedding. Didn't U get the memo about those tests? Why wouldn't NASA be perfect?

The smallest copter in the world was the

It flew for 30 seconds on a charge. 4 years after the Wowwee flytech, ornithopters R a no brainer. People build insect sized ornithopters all the time. U might as well go for something bigger & longer flying.

The mane problem with shrinking a tri rotor by overlapping blades is blades hitting shafts in a crash. With EDF40's, U need a lot more room for the ducts & they're real expensive to crash. The smallest tri rotor would be 7".

Any spin copter would be brushed, over 5", & use a custom 900Mhz radio on the same board.
Posted by Jack Crossfire | Jul 14, 2009 @ 11:43 PM | 5,130 Views
Getting a direct radio interface + flight computer out of a $3 microcontroller is not easy. Those 915Mhz front ends need full duplex SPI. U'd need some diabolical analog circuitry. U can afford a much more substantial microcontroller since you're dropping the $45 for an Xbee. Going with the analog solution lets U keep the existing XBee support. 915Mhz probably has shorter range, so U want to keep the XBees around. Despite the analog circuit, neither solution is any easier in the software.

The good news is the USB bit banger works. We can program & verify a PIC without a bootloader & in a humane amount of time. The advantage to running without a bootloader is of course, faster interrupts & less software to get working on every board.

The trick with the bit banger is U need to write 31 samples before U can read the 1st sample value. The workaround is to only set input enable when U intend to read & during the read pass, skip to the 1st input enable bit.
Posted by Jack Crossfire | Jul 14, 2009 @ 01:55 AM | 4,958 Views
It's cheaper than any purpose built BEC. It does work. It gets hot when converting 12V to 3.3V for a digicam, so no shrink wrapping. It's designed to be soldered on a board like a BGA, with airflow under the inductor. It needs odd resistors to determine the output voltage & can't use resistor dividers like the LM317. Sparkfun doesn't have the odd resistors, but digikey does, in addition to having the DC-DC converter.
Posted by Jack Crossfire | Jul 11, 2009 @ 10:08 PM | 4,530 Views
So many of U flood the blogs on weekends, writing blogs on weekends is almost as much of a waste of time as writing them on weekdays.

The reason Calif* is getting rain in July is Mt Sarychev. Ash plumes in the East Pacific always bring cold, rainy Summers to Calif*.
Posted by Jack Crossfire | Jul 10, 2009 @ 12:27 PM | 4,511 Views
LCROSS is heading towards a very large, motorized, Dobson mount, which can be bolted together in the field & stored for a human amount of rent. The mane problem is finding suitable bearings.

There it is. Our 2nd USB gadget is the bitbanger. It converts USB to 7 logic signals. Its purpose is a universal PIC, Atmel, JTAG programmer. For the PIC, U need a glue circuit to get 9V. For Atmel, U need a bag of resistors to lower the voltage.

We've been using the parallel port programmer since 2005. After 1 year banging on TTL chips, 3 years banging on 68HC11's, our first PIC gadget was HeroineClock using a PIC16f877. It now grinds away for 10 minutes on VikaCopter's firmware & more gadget needs keep coming.

Most of U implement USB or XBee bootloaders. With the number of gadgets & different communication methods we're using, that would mean implementing a new bootloader for every gadget....Continue Reading
Posted by Jack Crossfire | Jul 09, 2009 @ 01:47 PM | 4,863 Views
As U celebrate National Geriatrics Day, think about this.

U've outlived Karen Carpenter, Kurt Cobain, Brandon Lee, Heath Ledger, River Phoenix, John Belushi, & Chris Farley. They were all flat broke, account balance 0, & nobody by your age. Stick that on your scalp & grow it.

Now from the blog file, it's

How to win at red light cameras

Green lights R timed so everyone next to the solid white line when the light turns green can get across. At least in Fl*rida, yellow lights R timed so if you're going at the speed limit & you're in the solid white line, you'll make it. It's probably 1/2 the white line in bankrupt Calif*.

If the light is green when you're before the white line, slow down as U approach the white line. If it's still green when you're at the white line, floor it & keep going as fast as possible if it turns yellow. If you're behind someone real slow, get right up against their bumper so the cameras can't see your license plate. Don't worry about rear ending people. It's cheaper than a red light fine.

The whole idea with the cameras is to increase rear end collisions & create demand for higher medicare taxes which can then be diverted to mortgage bailouts.

Now some 1600mm shots....Continue Reading
Posted by Jack Crossfire | Jul 08, 2009 @ 02:51 AM | 4,460 Views
This lens is so powerful, it can see back into the 80's.

Let's get 1 thing clear. It's a piece of junk compared to Canon lenses. It's blurry at 800mm & extremely blurry at 1600mm. At 18oz fully loaded, it's too heavy for the trapezoid mount.

The answer is no. The 2x teleconverter doesn't buy any more resolution. The fact that the 2x teleconverter has no front lens cap shows how valuable its manufacturer thinks it is.

What the 2x teleconverter buys U is sharper focusing. If your goal is focusing bright objects, use the 2x teleconverter & throw away 1/2 the frame to get better focus. It's much easier to focus this way.

It's probably no better than a 400mm L & it's probably no better than a 200mm L + 2x teleconverter for $200 in 2007. Unfortunately the Canon 2x teleconverter jumped 50% since then. It's definitely better than a 200mm L as shown by this award winning blog post.

F/8 is a really narrow depth of field. F/8 & F/16 R not a problem when using a tripod & a modern digital camera. The Canon's focusing squares R useless. It's too blurry & dark. Unfortunately, F/16 brings out all your sensor dirt.

U need to fabricate a lens platform to mount it on a tripod. It's too heavy to hang off the camera body.

Focus guides on T mount lenses R worthless because they always go on the bottom, but it still has a focus guide....Continue Reading
Posted by Jack Crossfire | Jul 07, 2009 @ 01:36 AM | 4,599 Views
debbie gibson someday (4 min 4 sec)

Here it is. A monster of a video from the lost corners of the 80's. Mashed a pristine audio track with the 2 crummy Goo Tube videos to get the best quality possible.

After throwing together a layout for the 915Mhz radios, it became quite clear that any standalone data radio would probably be too heavy for a Picco Z size spin copter. It would need to do the processing + radio on 1 chip. Would also have to use the Maxbotix transducer instead of the Matsushita to minimize weight.

Vika 1 will be 915Mhz & get a new ground station specifically for 915Mhz & sonar. 915Mhz will use SPI & no RS232. Vika 2 will stay 2.4Ghz. Moving the radio to SPI is a pretty big change. We start with the ground station. Just need a USB cable.
Posted by Jack Crossfire | Jul 06, 2009 @ 04:36 AM | 4,420 Views
VikaCopter uses a PID gain for autopilot & a PWM gain for all modes. If U max out the PID gain, U have to increase the PWM gain. PWM gain was low to make it easier for a human pilot, but the human had to go. Here we have the 4 camera angle & nose in orbit with effective rudder & stabilization.

rudder effectiveness regained (7 min 8 sec)

The answer is no. The Castle BEC has no reverse current protection, so we finally fried it. It has a fuse diode which doesn't seem to have been enough. Lineage power makes buck converters which make all BEC's obsolete.

Now 4 your 80's minute.

Low quality audio without dropout, higher quality video.
Deborah Gibson Someday (3 min 52 sec)
...Continue Reading
Posted by Jack Crossfire | Jul 05, 2009 @ 02:52 AM | 4,419 Views
U may have tried to erase it from your memory, but we did dream about a flying flag many years ago. Flew VikaCopter higher & higher with a flag attached until eventually it didn't come down & it reached orbit. Months passed and the orbiting flag became a routine fixture at night, filling more space than the moon. Over time it became more tattered & faded from view because of micrometeorites & entitlement programs....Continue Reading
Posted by Jack Crossfire | Jul 04, 2009 @ 11:33 AM | 4,617 Views
Underslung payloads 4 U (4 min 15 sec)

There it is. All flights have to take off pointing North & turn into the wind because of the 3DOF IMU. Managed to pull off some stiff wind without blowing string into the propellers....Continue Reading
Posted by Jack Crossfire | Jul 02, 2009 @ 01:40 AM | 4,437 Views
Obviously, if U want smooth orbits U need a dedicated orbit command & not 4 waypoints joined by curves. Probably the only way to do it is to have the computer look 1 waypoint ahead. Unfortunately, U can't read 1 waypoint ahead in a C program.

Pretty major software change, & reason to give U the long orbit footage with the current software to keep the blog alive.

pico C programs & wind (7 min 5 sec)

Some hovers demonstrating the latest SCP1000 tuning. Then some pico C programs: a nose-in orbit, nose-out orbit, & some laps. 3DOF IMU, GPS, & SCP1000 of course.

None of these programs move very fast in any wind. Changing heading while moving is real hard. The idea of a curved path & heading changes is pretty hopeless in any wind.

Now some stills 4 those of U who don't have day jobs to spend watching Goo Tube.