And so is assembly language. Despite it's famous CEO, rediculous naming, and insane price tag, the Gumstix still requires a PIC to communicate with the real world. Also back is wireless telemetry. Decided wireless telemetry would be useful for collecting flight data
and easy to implement.

The wireless encoding ended up being based on transitions. A transition is any voltage change over a certain amount. A 1.3ms gap between
transitions is a 1 bit. A 0.4ms gap between transitions is a 0 bit. A 5ms gap is the start of a new packet. Packetizing allows byte alignment. Finally, a super simple CRC provided some error protection.

For capturing the data, the laptop wasn't an option. It only goes 45 minutes on a battery charge and requires a heroine to move it. To avoid hauling a laptop to the field, the waveform was recorded on an ancient minidisc recorder and decoded in the dumpy apartment.

During flight, the combination of Minidisc compression, large packet size, and interference only allowed 573 bits/sec. At that rate, the
copter could only transmit 5 data points per second, nowhere near enough to fly it. Of 1500 packets sent on one flight, only 727 were good. The error checking failed in several packets.

The biggest problem is setting the optimum gain to trick the audio compression, but the optimum gain depends on the ratio of 1's to 0's. All this stuff could be done by spraying huge amounts of money at 802.11 products, buying dedicated telemetry products, and buying a bigger copter of course. At least it's digital, mostly realtime, and much cheaper.

The wireless telemetry did its job, revealing the gyros are producing only 1V of voltage deflection in normal flying. The range was 0-1V. Going to need IDG1000's or serious op-amps.

wunderground wrote:
> Max Temperature: 73 °F

That's right, Bermuda Trapezoid fans. Calif* experienced the warmest February conditions in many years today. Unfortunately getting those
temperatures in February requires a very powerful offshore wind. Still not enough CO2 to do it by politics alone.

Those experienced in Bermuda Trapezoid meteorology know what affects Calif* affects the rest of the world 3 days later. Parked the copter at 10ft in the 30mph wind to measure the effect of translational lift on battery life. Got no improvement over figure 8's.

In other news, the FAA had some words for autopilot freaks.

FAA wrote:
> UAS issued experimental certificates may not be used for
> compensation or hire.

So in government speak, the FAA doesn't allow unmanned air vehicles to be used for any commercial function...

FAA wrote:
> The most common public use of unmanned aircraft today in the United
> States is by the Department of Defense.

unless it's for a government contract. You could say defense contractors are doing everything they can to keep competitors out, by creating legal barriers to entry.

Fortunately you can still manufacture UAV's for a profit. You just can't operate them for a profit. Also, to fly UAV's over U. Know. Where. you need the ability to manually override by line of sight, a rule that even defense contractors must obey.

Scream bloody murder, but recall a certain unnamed, so-called c.o.u.n.t.r.y. once complained about the lack of electronic voting, how India was racing ahead in new technology, leaving t.h.e.m. in the paper stone ages.

http://www.faa.gov/about/office_org/...ineering/uapo/

http://edocket.access.gpo.gov/2007/E7-2402.htm

So the guy from Singapore said our test firmware was workable. Since we already spent the $13 on a spare STR9, decided to spend the $9 to mount it. Sure enough, it failed the same way as the first one.

Good news: both chips are probably good. Bad news: some problem in the hookups is preventing them from running firmware.

It was more bad news in the wireless autopilot department. The TV transmitter was unable to transmit manual pulses over the video channel
and can only transmit voltage change over the audio channel. It would take a pulse width modulation scheme and 2 PIC's to move information over the audio channel, and it would probably be too slow. Further complexity would be required for error correction. Finally, this tremendous effort to make autopilot work over radio would have to be replicated for an onboard version.

So although the STR9 would have been ideal and we've plunged $80 into it, the hours on the airframe are building up, other things could be
happening in the months it would take to bring up STR9, and STR9 may get used someday in some other role.

Gumstix cost: $145 to buy some CEO on Sand Hill Rd. a house that we could never afford no matter how long we worked.

So after 2 nervewracking days of soldering, driving up and down Silicon Valley for parts, and imminent bankruptcy, finally verified all 4 gyros were working.

Gyros were the most expensive single part. By not requiring new gyros, it's $140 in the bank. The only hitch was destroying a surface mount capacitor by either overheating it or detaching the contacts.

It also proved our ability to mount chip scale packages on prototyping boards, saving a lot of money on the accelerometers. The hard part now is ensuring signal integrity over our recycled wireless parts.

So basically, decided not to continue with microprocessors of any kind and focus instead on inertial measurement devices, a much cheaper proposition. Someday we'll build a new STR9 board from the ground up and leave the current one unchanged until the new one proves it's unequivocably broken.

Now the idea is to use our collection of antique wireless equipment to offload the computation to a laptop until the system is proven. Only then can the microprocessor issue resurface.

Plan:

Prove current X/Y/Z gyroscope inventory works. If unsuccessful, consider spending $70 on just X/Y gyros.

Dump gyroscope data to PIC serial port and capture it on laptop.

Transmit PIC telemetry to laptop during flight using 2.4Ghz TV transmitter.

Achieve heading lock by using an antique transmitter to transmit commands from the laptop to the PIC. Our Airtronics from 1988 or
cordless phone from 1995 should do the job.

Expand envelope to cyclic and tail lock, using only gyroscopes.

Order $30 X/Y/Z accelerometer and add accelerometer data to telemetry during flight.

Achieve autonomous hover with laptop and dual transmitter scheme.

Buy $200 Gumstix. Achieve autonomous hover with Gumstix.

$50 GPS module.

Wishlist:

helihobby T-Rex 600 Silver Carbon kit
w/600L Motor
75G ESC/BEC
CF Blades $595.00 + tax
maxamps 22V 4Ah $170
Spektrum DX7 $350
CSM heading hold gyro $100
Total: $1215 + tax + shipping

Deal breaker:
Replacement blades: $80

Forget it.

Gumstix Basix 200 (never in stock) $100
Gumstix Basix 400 (usually in stock) $130
Gumstix breakout gs $30
Total: $130

Looks like the STR9 may be defective, but the only way to swap it is to destroy it. Going to destroy STR9 chip #1 and install STR9 chip #2. If chip #2 doesn't work, goodbye $130.

Since airport pictures are in vogue, have some shots from the last Japan trip.

So after 1 month of banging on the STR9 and getting nowhere, it looks like it would take a geologic time before it ever got to the autopilot
stage.

Despite it's insanely high prices, quirky product names giving no clue to their function, and a tedious search tool for an inventory of only 6 motherboards, Gumstix is the next most economical solution.

Now seriously considering the $200, 400Mhz Gumstix. Since it has almost no GPIO's and no A/D inputs, it would require a PIC to communicate, but we already have a PIC ready 2 go. The Gumstix would almost eliminate the bringup step, be a lot easier to program, and have a lot more clockcycles, but wouldn't be cheap enough to use in any other projects like the STR9 could have if it worked.

The last STR9 experiment was to connect all the power pins. It seemed unnecessary because they're all shorted and sure enough, it did nothing.

Backwards figure 8's are starting to come easier. Not nearly as accurate as our forwards figure 8's but slowly getting easier.

At 27 min, parked it at 15 ft to wait for the battery to fade. The battery didn't fade. It just died at 10ft. Best tail boom strike ever. The pop sounded like a gun, reminding you of what it could do to a human hand.

5.6 hours since the last dead battery drop. 6.9 hours since the last full crash. With enough padding and exclusive deployment as a camera ship, we're probably ready for a TRex 600.

TRex 600 is the dream copter but the $2000 isn't being made. Every year the $2000 gets swallowed by another rent increase, another 20% gas increase, another 20% food increase. Still only 2.5% inflation.

So decided to fly every day this week in honor of Lion Astronaut's departure from the searly bonds of Earth and into the great beyond. The physical side may still be around, but the mental side has joined her sts-107 and sts-51 comrads.

That means flying in whatever rain, wind, and U. Know. Where. U. Know. Where. throws at the copter. The answer is yes. You can fly in 20mph winds and light rain.

Always give it extra upwind cyclic.

Use large stick movements.

Assume when the wind is hitting it sideways that it wants to flip over downwind.

When translating downwind, use tons of extra power. When translating upwind, use super slow throttle.

Keep it close and low since it tends to pick random orientations.

Use the 4Ah battery since it's heavier.

You get really good chopping sounds when cutting throttle and translating upwind.

A heroine being the first to commit astronaut incest makes it a sad day for heroine worshippers. All these years they said men were professionals and heroines were nothing but trouble and the heroine was nothing but trouble.

Someone is going to make Fatal Astronaut Attraction, in which a heroine spends 6 months on the space station with another heroine, a man, a steel hammer, knife, and some garbage bags.

It is the largest ocean liner ever made by the hand of man in all history.

Queen Mary II was modeled after Titanic. In fact, it was intended to fill the same role as Titanic, the living reincarnation of Titanic, U might say. It's the largest ship to enter San Francisco bay.

Expected to be one of a few people viewing the ship and get up close, but was greeted by mobs of desperate Americans stepping over each other to glimpse the European marvel. It was like being in Titanic....Continue Reading

So after the victory at JTAG, it's been nothing but grief. The program which is supposed to turn on a GPIO either isn't running at all, is running but not setting the GPIO properly, or the chip is dead. The flash is programmed right. The configuration bits are set right. Now it looks like the $70 JTAG programmer may be required again to debug this problem. So much for autopilot.

In other news, managed better success by flying backwards, pirouetting, returning backwards, pirouetting, flying backwards. A few iterations later, use aft cyclic during the pirouette and you get slight widening of the figure 8 before the sideways cyclic inputs get too complicated.

Finally, for a good time go to

http://heroinewarrior.com/robotics.php3

Since no-one is going to that, we're going to put neverbeforeseen photos on here to hook you. Then you'll be sucked in by a power greater than U have ever known. Heroine 2200 is going to need a 3rd tower soon, then she'll never be the same. 2 was the magic number.

So the most challenging trick in a fixed pitch copter is the backwards figure 8. Don't even bother in an airplane. Concluded we have trouble
seeing roll attitude from 10 oclock. The solution: nose-in/sideways passes, sideways in and out, and backwards figure 8's. They're probably
not possible without a heading hold gyro, and in no circumstances can they be fast.

In other news, the copter hit 50. 50 hours of flying. Would U believe the first few hours were spent just trying to debug the receiver? The
controls randomly froze after a few seconds of hovering. Other times the motor would stop at random points. The controls wouldn't return
until several minutes after it crashed, usually in the form of sudden motor spins after several minutes of prodding. Took several days to
figure out the crystal was loose.

Would U believe the very first flight resulted in a hover with the copter spinning out of control? Didn't even try again that day. Only a
day later realized the solution was to invert the gyro.

Hard to believe it was once that hard.

Lost the port LED strand at 15ft nose-in. R, W, B suddenly became a single strand of W, B. Flying with only W, B, is equivalent to going blind, no orientation, no direction, cluelessness. Nevertheless, managed a nose-out, terrifying, part tail boom, hard landing despite W. B.'s best efforts.

After repairs, and proving our copter was still all there, the battery died after 22 minutes. In 10 mph wind, noticed it was getting harder to maintain altitude but was too occupied chasing a police copter to remember the time. Air starting a Castle is a complete waste. It's just an RWB brick.

It's "the height of irresponsibility" for a copter to pass the laws of physics along to a pilot.

So the autopilot remains stuck at hello world. Managed to verify the flash programming. Turns out the reset pin was never being grounded because it was connected wrong. That led to programming errors. The verify step always worked. Now it appears to either get partway in the program and die or not run the program at all.

Had 2 anomolies during today's flying routine. After a 40mph pass, did a rapid pull up + throttle kill, then rapid push down + throttle spike. Heard the sexy sonic boom chops followed by a new gear clicking sound. Then a sudden yaw to nose-in, against the tail rotor happened. Thought the tail rotor died again but managed to regain control. The tail reduction gear may have slipped from an unusually high rotor stress.

Our final anomoly was a rapid nose-in approach followed by quick pull up + throttle kill + push down + throttle spike. Had a sudden roll left. Fought it for a few seconds but never could regain control. The second day in a row of sudden rolls.

They say dissimetric lift causes retreating blades to gradually lose effectiveness, but we encounter extreme instability and sudden 45` rolls when moving at high speeds. Anything beyond a 33` roll seems unrecoverable with this copter.

Could always just fly slowly and hover once a week, but if you're not crashin you're not tryin.

So getting hello world to work is proving as difficult as getting JTAG working. First of all, the ISC_BLANK_CHECK command on the STR9 is documented wrong. Blank sectors return 0. Written sectors return 1.

Secondly, the ISC_READ command is returning random data for the flash contents. The same thing happened with PIC micros, except now ISC_READ is returning valid data for the configuration register.

Removed the STR9 library in favor of manually setting the registers. The STR9 library added 10000 bytes to the executable. Without it, hello world is 68 bytes. Hello world isn't working of course.

In today's crash, was doing sideways/nose-in movement. Got it going pretty fast upwind. Then on the direction reverse it suddenly rolled excessively left. Applied right cyclic with very limited results. Seemed to run out of room, so instead of throttling up, killed it. Not sure how it ran out of room, besides flying in the most overcrowded country in the universe.

In other news, The Canon passed exposure 50,000 today while shooting another sunset movie. If it was an EOS 350D it would have died by now. If it was a 350D, would have probably had no trouble spending the extra $200 on an XTI at this point.

After 2 weeks of mane hair removal, imminent bankruptcy, 3 programming circuits, 10,000 Win2000 reboots, and EE purgatory, the STR9's JTAG works. Got good return values for a chip erase and a configuration register write. The flash banks are now supposedly reordered so it boots into the 32k and can use a bootloader there to program the 256k.

All the success was achieved by custom software in Linux. The CAPS tool was a complete waste of time. Still much 2 do: running hello world, developing a bootloader, and programming the 256k flash.

In other news, was thinking about the Silicon Valley tech fad followers who are buying $500 bikes because they fold up, instead of a $200 electric scooter which takes up less space than the folding bike, because their corporate idol CEO rides a folding bike.

If there was a way to transport the copter on a scooter, we would have a pretty huge incentive to make the Razor E300 happen when gas hits $3.50 again, but the scooter doesn't have any cargo room. The copter is drastically cheaper to fly than the car is to drive.

Had 22 min of good sonic booms with the copter, but the lowest flight time ever. They seem to come easier in warm, moist conditions. Bring it up to 150 ft, idle the throttle and pitch hard forward, the combination of rapid descent and forward movement gets those blade tips up to 650mph.

kiwipedia wrote:
> the 747 broke the sound barrier during certification tests.

FYI, all the set screws are lock tightened of course. Don't have the balls to put threadlock on a shaft because of the risk of threadlocking the $100 bearings.

No matter how tight they are, they naturally come lose as a function of routine stresses, but exactly which set screws come lose the fastest is still being discovered. The forward tail pinion came lose after 12 hours. The motor pinion came lose after 45 hours. All the others have been solid.

Since flattening the tail wire, the tail pinion has never loosened. Still undecided on grinding the $100 motor shaft.

The motor set screw is particularly hard to reach, requiring dismantling the spur gear & motor to get at. Being a fat shaft made it the least likely to slip but it did. Also stripped a set screw in the spur gear during yesterday's replacement, so they can be overtightened.

In other news, after giving up on CAPS, free JTAG tools, and starting to write a JTAG programmer from scratch, finally started getting something resembling useful JTAG results. The trick is the way the JTAG "taps" are wired in hardware.

With the STR9 came a diagram showing the 3 devices contained in the STR9 package and how the JTAG signals are connected to them. TCK, TMS, and TRESET are parallel, meaning all 3 devices get the same signals, simultaneously from those wires.

TDI is series, meaning the TDI signal has to bit shift through one device, then another, and another until it gets to your target...Continue Reading

So after 45 hours of flawless operation, the motor setscrew came loose at 100ft. Started losing power and hearing a gurgling sound but didn't know what was happening. Then during the descent started losing altitude real fast and the gurgling got louder. Adding throttle did nothing. Finally there was no power and it hard pledged allegiance. Out of ny ties.

Was it a dead motor? Would we buy a new motor or scrap the Corona, get a T-Rex 600, and start collecting motor induced poverty entitlements?

Fortunately it was just the motor set screw coming lose. The word "set screw" appears twice in the crash log. The word "USA" appears 22 times.