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It turned out to be an 8975 instead of an 8973.  By some contact lens malfunction or erroneus Goog search, we thought it was an 8973 all year.   The 8975 has a completely different pinout than the 8973.  The power pins were shifted around.  An SPI interface was added.  The reset pin was removed.


The magnitude of the changes, number of revisions, & fact that it's used in the iPhone lead us to believe Steve personally required many minute changes of a cosmetic nature.

It was the chip in the iPhone 4.  It requires no external components.  It's not sold to private individuals, but it was free.

After banging on it for a while, finally caved in & built a 2 channel oscilloscope for USB.  It captures 2 channels at 130,000 samples/sec with DC coupling.  It can do a single channel at 260,000 samples/sec.  Much better than the soundcards we've been using for 10 years, but disappointing that 11 years of working didn't produce enough money for a proper oscilloscope.

That immediately showed our I2C was generating a 0 for the ACK where it should have been generating a 1 & the problem was solved.  Electronics are a lot easier with an oscilloscope.  The only other chip using I2C was the IDG3200, which didn't work in bulk transfer mode, so it ignored 0 ACKs.

We don't use hardware I2C unless the bandwidth requires it.  The restrictions on what pins to use are too severe.

Now another item which was delayed way too long.

It finally runs on USB instead of its own, always dead, NiCd.  It seems to work on just 5V instead of 9.6.  It turns out it uses the 9.6V to bias an LM324, which amplifies & lowpass filters the pots to 0-3.6V.  This op-amp has a pretty bad dropout voltage, so 5V is cutting it pretty close.

Making the transmitter run on USB was really needed for long duration bench tests.

All 8 degrees of freedom, GPS, & barometer reloaded.

All was as it was in July 2009, when we last flew with a magnetometer. Neither did it feel like the matter was making us fall in love with a golfing Air Force major, as we felt after July 2009.

Now we have attitude hold in manual mode.

Barometer was too close to the edge, making for less stable altitude.

Going with the pure gyros & no magnetometer was possible, but never the most stable.  This is the maximum stability.

Not going for automated takeoffs because we're broke.  Those caused a lot of crashes.  If anything doesn't work in an automated takeoff, it's gone.

That was it.  There's nothing yet to be discovered with Vika 1.  She's going to stay a standard autopilot.



The time for a real oscilloscope may be coming near, as we have dreams of custom software radio to receive the space station.  The current rig can get AM below 130khz.  Maybe a custom AM radio could overcome the urban environment barrier.

The way we see it, the great task in a custom space station receiver is making a 145Mhz local oscillator.  An alternative could be multiple conversions with readily available oscillators.  Do 1 with a 100Mhz, another with a 40Mhz, & another with a 5Mhz.  Sample the result with a 1Mhz ADC.

The other thing on our mind is launching something into space.  The way we see it, the most a private individual can afford to get over 62 miles up is a single bacteria or maybe something slightly larger.  Bacteria are manipulated using photonic pressure all the time, under a microscope.

The mane problems are detecting where the bacteria is, in order to aim the laser, & overcoming wind.  Bacteria can fluoresce or reflect the light of the manipulator beam.  This can be detected by a large enough telescope even if it can't be imaged.

The wind couldn't be overcome, so the manipulator beam would only be able to increase altitude, following it wherever the wind blew it.  Once high enough, the manipulator beam would be able to add horizontal velocity.

The only real benefit from this excercise would be to show the light received on a telescope was indeed from an object that you put in orbit.