Fix bug in conditional acoustic recording.

Fixes

- Sampling "only while no sample of..." could fail

Known issues

- Accelerometer readings, especially the vertical axis, affected by depth
- Sample-time decimation for high-frequency channel unavailable
- Processor behavior can induce small artifacts in 3B light-level channel

Tweaks for issues introduced in AcOS 3.0.5.

Fixes

- Compass test & calibration could hang due to IR deafness (introduced in 3.0.5)
- Build identifier was no longer shown in log or Palm app (introduced in 3.0.5)
- Log entries for IR "bombardment" were too verbose (introduced in 3.0.5)

Enhancements

- Better handling of infrared noise causing wake-from-sleep

Improved robustness in the face of infrared noise, especially while in sleep or standby.

Fixes

- Uses less power in sleep or standby when encountering IR noise
- Fewer false positives when detecting IR noise
- Reduced chance of crash when writing log entries in sleep or standby (rare)

Enhancements

- Vastly improved temporary-deafness response to heavy infrared noise

Tweaks for IR offload of acoustic data and power-system handling and reporting.

Fixes

- Battery-test fail threshold (lithium batteries) slightly more generous
- Better logging of boost-converter status (Acousonde 3A only)
- Alert (red) LED less likely to "stutter" when flashing sleep alert

Enhancements

- Support infrared offload of acoustic data (for when USB unavailable)

Palm "Acousonde" commanding app changes, new version 3.0.4

- "Battery" pane "Test" command now shows detailed numeric test results
- Factory user can prohibit remount of filesystem after rebuild (for IR offload)

Better handling for conditional-sampling modules and severely depleted batteries.

Fixes

- Conditional sampling could freeze the deployment log
- Better battery analysis and logging at boot
- Enter deep shutdown at boot if battery found to be severely depleted
- Better handling of hardware battery boost (Acousonde 3A only)

Enhancements

- Log module's test-conditional preset (if module supports doing so)
- Lower power draw in deep shutdown

Better support for manual battery testing via the Palm. Backwards compatible, but the new feature requires both Palm 3.0.2 (or higher) and Acousonde firmware 3.0.2 (or higher).

Palm "Acousonde" commanding app changes, new version 3.0.2

In response to manual battery test, app now:
- provides Acousonde's analysis of its battery type and condition
- shows Acousonde's temperature and quiescent voltage for manual battery test

Enhancements

- Acousonde provides more complete manual battery-test information to Palm

This major release introduces modularity. Third parties may now write "modules" (similar to plugins or extensions) that alter AcOS behavior without needing to modify the operating system itself. Modularity support required significant reorganization of the operating system. A suite of callable functions, such as FFT and inverse FFT, have been added to AcOS for access by module writers.

Further, this release adds "conditional sampling", that is, determining whether to sample acoustics depending on whether auxiliary sensor data meet specified conditions, such as depth below a given threshold.

AcOS 3 also supports new 16-bit attitude/orientation hardware. This hardware is presently only available in new Acousonde 3A units, but is expected to be incorporated in a future redesign of the Acousonde 3B.

Besides the major new features, AcOS 3 provides many other fixes and enhancements.

Palm "Acousonde" commanding app changes, new version 3.0.1

- New Module control pane
- Conditional control pane now supported, with expanded features
- Support built-in sampling rates of new combo compass/accelerometer hardware
- Support 20/200 aux sampling scheme
- Additional & clarified alert dialogs
- Backwards compatible with AcOS 2

Fixes

- Improved USB support for Windows 10, MacOS Mojave, & later
- More robust IrDA signaling

New module capability and support for future telemetry

- Internally reorganized AcOS to maximize simplicity for module writers
- Module handling (install, activate, deactivate, query, presets, etc.)
- New Application Programming Interface (API) for module use
- FFT and other functions available for module use via API
- Receive new modules via IR transmission
- Packetization and transmission-queueing support (for telemetry)
- UART support for communication with third-party hardware (for telemetry)
- Wet/dry switch support (for radio telemetry)

New conditional acoustic sampling capability

- New, flexible conditional acoustic sampling system
- Simple conditional monitors can be configured at deployment time
- More complex conditional monitors can be programmed by modules
- Strobe in Acousonde 3B now triggered by floating detection

Other enhancements

- Expanded HTML report provides firmware, API, bootloader, and module versions
- New 16-bit attitude/orientation hardware support
- Hooks for future higher-quality pressure/compass/accelerometry calibration
- Optimized all remaining unoptimized code

USB Bugfix. Final release of AcOS 2.

Fixes

- Some units would occasionally hang just before mounting via USB

Known issues

- Accelerometer readings, especially the vertical axis, affected by depth
- Sample-time decimation for high-frequency channel unavailable
- Processor behavior can induce small artifacts in 3B light-level channel

Bugfixes.

Fixes

- Sync monitor during sampling (rarely-used feature) could break accelerometry
- Bootup might hang during red LED flashing (introduced in 2.6.0)
- Bootup on USB could hang on units with some new 64 GB storage cards
- Aux filesystem accessed via USB might rarely be corrupted for newer units
- Some 64 GB storage cards could report errors when turning on under duty-cycled sampling
- Infrared transmission of log or data files could abort (very rare)

New, faster LED brightness-cycling/flashing added as initial part of bootup sequence; indicates when already-acquired auxiliary data are being analyzed, before main storage rebuild continues with slower LED brightness-cycling/flashing. Performance tuning "under the hood" for 1% to 2% reduction in power consumption. Fixed three issues that could cause auxiliary sampling to end prematurely, and one issue that could cause duty-cycled acoustic sampling to end prematurely. Improved USB compatibility with Windows 10. Improved sampling-shutdown logging and LED behavior, especially for duty-cycled acoustic recording programs and/or when auxiliary storage has filled.

Fixes

- Aux sampling could hang sometimes with slow acoustic & fast aux sampling
- Duty-cycled acoustic sampling could end prematurely if aux storage filled first
- 40/800 aux sampling would fail if slow primary sampling ended first (rare)
- Fast accelerometry more resilient during rare acoustics storage-error retries
- Reduce USB disconnect tendency of some Windows 10 instances
- Alarm-based aux sampling could start 1 s later than alarm time
- Sampling shutdown when aux storage is full could cause puzzling LED flashing
- Shutdown of duty-cycled acoustic sampling could cause redundant LED & log alerts
- Improved acoustic data-storage recovery for certain storage errors (rare)
- Wipe-and-reformat for new 2GB Flash chips would fail (factory use)
- USB partition map error (only seen with 128 GB SD cards used in testing)

Enhancements

- New fast LED flashing at bootup during auxiliary-data inspection
- Tune internal data transfers for improved power efficiency
- Faster infrared handling (leaves more resources for data handling)
- Compile with GCC 7.3.0 for more efficient code
- Improve error logging/handling for debugging purposes

Not released to general user community.

Fix to 232 kHz acoustic + 40/800 auxiliary sampling instability.

Fixes

- Fixed instability in long-duration runs of the most demanding sampling regime

Fixes to USB file system and logging for rare circumstances.

Fixes

- Single files shown via USB might have been two or more files concatenated (rare)
- Removed alarming but unnecessary log entry associated with mapped-out storage (rare)

Support new 2 GB flash/auxiliary storage; improved primary-storage fault tolerance.

Fixes

- Could enter inconsistent state if stopped during sampling startup
- Bug made recovery from primary-storage hardware glitches unlikely
- Activity log could end prematurely in the event of primary storage errors
- Near-dead battery could flood log with fault messages at startup (rare)

Enhancements

- Support new 2GB auxiliary-storage flash chips
- Vastly improved recovery in the case of failing primary-storage cards
- Much more detailed log information on failing primary-storage cards
- Easier for users to map out dead primary-storage cards

Add USB support required by some instances of Windows 7.

Fixes

- Windows 7 sometimes demands a certain USB response (that spec calls optional)

Minor improvements to log file.

Enhancements

- Log file includes clearer comments about power status/analysis on startup

Support start-on-reset functionality. Fix use of main oscillator for clocking (custom application).

Palm "Acousonde" commanding app changes

- App 2.3.1 supports start-on-reset feature

Fixes

- Better Palm feedback when stopping a unit in sleep versus one that is sampling
- Recheck sanity of delayed-start wakeup time when user "Execute" command received
- No longer attempts to write auxiliary files for a channel marked non-functional (rare)
- In unusual cases, LED standby blinking would cease
- Fixed use of main oscillator for clocking (rare application; broken since 2.2.0)

Enhancements

- Selecting "start on reset" starts the sampling program after reset (but not at initial power-up)
- Last saved "start on reset" program loaded as default on power-up, even if not enabled
- Magnet held on reset switch through reboot engages deep shutdown
- Deep shutdown maintains clock at 1/4 typical sleep/standby power, unit otherwise off

Fix minor logging error introduced in 2.2.5.

Fixes

- Would log USB power as a lithium battery (introduced in 2.2.5)

Stability improvements for rare situations.

Fixes

- Top-of-minute "heartbeat" LED could cease unexpectedly (rare)
- Improve stability of low-power handling system for 3A units
- Improve stability in the face of uncommonly severe storage card failure

Enhancements

- Now logs battery type detected for lithium as well as alkaline types

Support for new electronics and future improvements.

Fixes

- Erasing storage on certain older units now up to 6x faster
- Minor cosmetic improvements to log file and HTML configuration report

Enhancements

- Support higher-capacity storage for future units
- Support new Rev 10 Acousonde electronics
- Improved support for removable media in custom applications

User-interface improvements for uncommon events.

Fixes

- Under rare circumstances HTML unit-config report would not appear
- If recording aux only, some units would report 40-dB acoustic gain to Palm

HTML unit-configuration report prepared and placed in auxiliary partition when booting on USB.

Fixes

- Under rare circumstances aux filesystem would not mount properly on USB
- More efficient logging behavior when aux data storage nearing capacity

Enhancements

- HTML-formatted unit-configuration report now available in aux partition
- Possible to offload acoustic data via infrared (very slowly)

Palm "Acousonde" commanding app changes

- App 2.2.1 supports additional factory test/debug tools

Fixes

- Top-of-minute LED flash didn't always resume after end of sampling
- Version 2.2.0 would not fully detect some Samsung data storage cards
- Minor improvement to power-fail behavior
- Clarified auxiliary filesystem capacity-used reporting to Palm
- Better fault tolerance in acoustic-data file system
- Improve balance of acoustic and auxiliary digital data/signaling paths

High-time-resolution accelerometry. This capability required major "under-the-hood" changes to auxiliary data handling and storage.

Palm "Acousonde" commanding app changes

- App 2.2 supports new auxiliary sampling capability

Fixes

- Significantly reduced the potential for aliasing in accelerometer channels
- Very unusual choice of acoustic sampling program could "brick" unit
- Better fault tolerance in auxiliary-data file system
- Reliability improvement in acoustic sampling driver
- Logged filename indices could lose correspondence with USB filename indices

Fix since 2.0.0c beta release

- Files of slow- and fast-sampled aux data now cover same time period

Enhancements

- Maximum accelerometer sample rate raised from 20 to 800 Hz
- Maximum compass sample rate raised from 20 to 40 Hz
- Can sample depth & temperature at 1 Hz even for nominal aux rates of 5 or 10 Hz
- 3B models now sample light level along with other aux channels
- Big changes to Flash-memory storage code to support faster aux data rates
- Big changes to logging functionality to coexist with fast aux data
- Migrated from gcc 4.4.4 to gcc 4.7.3 for better compiled-code performance
- Vector floating-point coprocessor enabled for future development
- Broader USB code for eventual USB device compatibility with Linux hosts

Tuning.

Palm "Acousonde" commanding app changes

- App 2.1.3 minor clarifications to warning and information dialogs

Fixes

- Sampling HF channel sometimes did not stop for some time after Palm stop request
- Spurious log errors triggered by retrieving Palm app via IR (introduced in 2.1.8)

Enhancements

- Bootup filesystem-rebuild process faster and uses less power
- More accurate battery-voltage measurement
- Support new flash-memory hardware for future units

Significant reduction in power consumption.

Fixes

- More robust handling of infrared activity during sampling
- More robust auxiliary sampling when processor near maximum load (rare)
- Better recovery from (very rare) SD-card read errors when offloading data
- Probable fix for (very rare) crash during infrared transmissions
- Better identification of lithium battery (only newer 3As with boost converters)

Enhancements

- Fast sample rates (116 kHz, 154 kHz, 232 kHz) use ~15% less power than 2.1.5
- Slow sample rates (e.g. 25 kHz) use ~7% less power than 2.1.5
- Filesystem rebuild 1.5x to 2x faster
- Bootloader 1.5x faster (bootloader requires separate update process)
- More helpful reporting to Palm of storage capacity remaining

Improved power-fail dectection behavior.

Fixes

- Reduced likelihood of spurious power-fail shutdown when operating near freezing
- Auxiliary sampling can't power-fail before primary (acoustic) sampling
- User end of sampling turns off strobe if it had started automatically (3B only)

Enhancements

- 3% to 5% reduction in power consumption at 116, 154, and 232 kHz sample rates
- Fewer "power fail (ignored)" log entries especially when operating near freezing

Bugfixes.

Fixes

- Under rare circumstances a 3B log might fill with a bogus error message
- Units without boost converters (old 3As, all 3Bs) didn't detect dead alkalines

Power-handling bugfixes for the special case where aux channels only are being sampled (for example, after acoustic storage has filled or power has fallen too low to maintain acoustic sampling).

Fixes

- More robust power-fail detect & shutdown when only aux channels being sampled
- New 3A units with boost converter (A027 and later) might not use it when needed

Bugfixes.

Fixes

- Some accelerometers gave erroneous data when acoustics sampled at high rates
- Enable user access to 464 kHz sample rate
- Fix premature sampling failure at low acoustic sample rates (introduced in 2.1.0)
- Fix unexpected USB disconnect during offload to Apple Mac computers
- Fix failure to prepare aux filesystem for offload under rare circumstances
- Increased stability during power-fail handling

Bugfixes for issues introduced in 2.1.1.

Fixes

- Alternating sample rate could result in occasional missing files
- Recovery from SD card hardware errors had been accidentally impaired
- 2.1.1 could not sample the HF channel except under alternating sampling!

Support for alternating sampling rates, that is, X minutes of low-power channel alternating with Y minutes of high-frequency channel (only applies to units with the high-frequency option); and bugfixes.

Palm "Acousonde" commanding app changes

- App 2.1.1 allows user programming of alternating sample rates

Fixes

- More efficient sampling aux channels at 20 Hz when sampling acoustics < 26 khz
- Remember low-battery status after stopping sampling for power reasons
- Duty-cycling or alternate-sampling acoustic hardware has less impact on auxiliary data
- Fix case where all storage cards could be marked full when empty cards available
- Better bootloader behavior when installing on raw (new) boards

Enhancements

- Alternating sample rates

Power consumption reduced by as much as 50% depending on sampling configuration. Maximum sample rate for high-frequency units now 232 kHz (units built since August 2011 incorporating the latest 32GB MicroSD storage cards have demonstrated a sustained sample rate of 464 kHz).

Important: Firmware 2.1 changes the communication protocol between the Palm and the Acousonde. Earlier versions of the Acousonde Palm app WILL NOT WORK with Firmware 2.1, and likewise, the new 2.1 version of the Acousonde app WILL NOT WORK with Acousonde units running Firmware 2.0.x. This means that groups operating multiple Acousonde units should be sure to update the firmware on all of them, so they all speak the same infrared "language".

As always, when updating the Acousonde firmware, it is important to update each Acousonde's onboard copy of the Acousonde PalmOS app as documented in the firmware updating guide. This ensures that each unit can provide a compatible version of its commanding app upon request. In this case it is critical to do so, as a earlier "stale" version of the commanding app will be incompatible with an Acousonde running firmware 2.1, potentially resulting in mission failure.

Palm "Acousonde" commanding app changes, version 2.1.0 (4 March 2012)

- INCOMPATIBLE WITH ACOUSONDE FIRMWARE 2.0.x; must use new app with 2.1
- Supports new maximum 200 MB file size, default file size now 100 MB
- Asterisk marks "10 Hz" as TrackPlot-preferred auxiliary sampling program
- Fixed "Clips @" (request for clip levels) under "Check Sensors" pane
- Supports activation of 3B strobe during sampling (for video synchronization)
- Placeholder support for planned features

Fixes

- Fixed crashes associated with offloading data from multiple storage cards
- Fixed crashes associated with switching storage cards in older units
- Possible fix of rare bootup hang on certain units
- Improved stability and speed of IrDA transactions
- Fixed bug preventing full use of sampling memory (improves error recovery capability)
- More precise logging of adjustable anti-alias frequency value
- Refuses to execute sampling if sampling configuration errors present
- Bootloader now uses only yellow LED

Enhancements

- Enabled 232 kHz and, for newer units, 464 kHz acoustic sample rate
- Retuned system clock speeds for significant power efficiency
- Dynamic core voltage adjustment further improves power efficiency
- Supports faster performance and lower power consumption for the latest storage cards
- Improved stability when offloading data via USB
- More thorough logging of causes & timing of sampling shutdown
- Increased available file sizes, now 20, 100, and 200 MB, with 100 MB the default
- Slightly less aggressive automatic setting of adjustable filter cutoff
- More precise explicit time synchronization when running at low power
- Longer recording life for newer 3A units running on alkaline batteries
- Clarified user alerts for potentially too-high sampling rates
- 3B strobe aligned with time-of-day to aid visual/video synchronization

Support for offset duty cycling of acoustic sampling (see the Technical FAQ for a description of duty cycling, including the new offset/delay capability).

Palm "Acousonde" commanding app changes

- Version 2.0.6 allows programming offset duty cycles

Fixes

- Fixed inability to talk via infrared with Palm Tungsten T3

Enhancements

- Offset duty cycling of acoustic sampling

Support for multiple storage cards.

Palm "Acousonde" commanding app changes

- Version 2.0.5 supports storage-getting-full warning

Fixes

- Attempt to fix very rare crash during IR transactions and strobe flashing
- Clarified log statements noting end-of-sampling
- Fixed unintended locking of time-of-day clock by any sampling operation

Enhancements

- Stores acoustic data to multiple storage cards
- USB device mode makes multiple storage cards available to host PC
- Erase operation erases all storage cards, not just the first card
- Added storage-getting-full warning when configuring sampling via Palm

Alkaline battery support for new 3A units. No need to upgrade existing units.

Bug fixes.

Palm "Acousonde" commanding app changes

- Version 2.0.4 includes additional factory-checkout dialogs

Fixes

- Fixed occasional miss of sampling periods in duty-cycled recording
- Fixed rare concatenation of two or more sequential acoustic files
- Fixed occasional hang of certain units during boot
- Fixed memory test (factory checkout tool) failure in certain circumstances

Compass calibration and testing.

Palm "Acousonde" commanding app changes

- Version 2.0.3 required to calibrate and test compass

Fixes

- Support for both new and old compass/accel axis configurations

Enhancements

- Compass testing, per-channel
- Compass calibration with user interface

Adds second-order thermal offset correction capability on pressure channel; also support for new Acousonde 3B features.

Palm "Acousonde" commanding app changes

- Version 2.0.2 required to test strobe (in Acousonde 3B units only)

Performance

- Slightly lower power consumption when sampling full auxiliary suite
- Faster booting when auxiliary filesystem contains many files

Fixes

- Fixes to duty-cycled sampling when combined with delayed start
- Improved stability when setting and clearing delayed-start sampling
- Improved stability of LED flashing during various operations
- Improved stability when reformatting boot device
- Fixed rare crash when stopping sampling
- Properly handles disconnected channels, if any

Enhancements

- More thorough and repeatable battery testing
- Gracefully reject attempt to record from missing optional hydrophone
- Configuration file supports storage of high-pass cutoff values
- Supports second-order temperature offset correction for depth sensor
- Support for recovery strobe (Acousonde 3B units only)
- Support for ambient-light sensor (Acousonde 3B units only)
- Acousonde can store and upload a clock app for the Palm
- Added memory self-test capability

Fixes

- Fixed crash and possible dropped samples at certain sample rates
- Zeroing pressure now applies immediately instead of after next restart
- Fixed roundoff error with sampling rate returned during Palm interaction
- LED flash type when sampling starts now more representative

First release with all functionality in place. Now supports sampling of auxiliary channels (temperature, pressure, kinematics) and duty-cycling of primary sampling.

Palm "Acousonde" commanding app changes

- Version 2.0 required (earlier lettered versions not fully compatible!)

Fixes

- Auxiliary/logging/bootcode filesystem more robust in case of errors
- Fix for very rare sd-card write failure
- Fix for firmware corruption in certain units

Enhancements

- User warned if battery is low by a different standby LED flash
- Timing of top-of-minute LED flash more precise
- Other LED flashing behavior more consistent
- More sampling details written to log file

For acoustics-only recordings. Better responsiveness to infrared stop-sampling command.

In addition, 2.0.0z adds the capability to receive (via infrared) and store the "Acousonde" .prc PalmOS app on board the Acousonde itself. An Acousonde loaded with the PalmOS app can send it out to a Palm unit that lost, or never had, this app. To do so, the user runs the Palm's built-in "Memo Pad" app, creates a new text memo with a first line that reads "Send", and beams the memo to the Acousonde; the Acousonde responds by transmitting the Acousonde.prc app to the Palm. This capability saves the user from needing to install Palm synchronization software on their desktop computer, or needing to keep a synchronization cradle/connector for their Palm. The user must still ensure that the Palm's batteries are charged and that the Palm's time is set correctly.

Palm "Acousonde" commanding app changes

- Version 2.0e required to take advantage of warning dialogs

Enhancements

- Better responsiveness to infrared stop-sampling command
- Can store and send PalmOS "Acousonde.prc" app
- Adds warnings for sample rates unlikely to work
- Configuration file can be used to map out problematic memory card(s)
- Optical sync with real-time clock is more accurate

For acoustics-only recordings. Bug fixes.

Fixes

- Really fixed rare power-up into inconsistent state this time

Enhancements

- Erase operation faster on all units

For acoustics-only recordings with better deployment-life stability.

2.0.0w dramatically changed the Acousonde's filesystem-maintenance paradigm. Instead of maintaining the internal filesystem during logging, 2.0.0w abandoned filesystem maintenance and simply wrote data "blind" to consecutive sectors on internal storage. Then, to present the user with a good filesystem, 2.0.0w examined storage at every power-up or reset and generated a corresponding FAT filesystem from scratch. This change increased reliability.

A side effect of this change was that "fast erase" (simple reformat) could no longer be supported for the internal SD cards. They could only be "full erased", that is, completely wiped. Otherwise the filesystem rebuild could get confused.

Note: customers who configured the Acousonde to write to an external USB flash drive were unaffected by the above changes. Blind writing was not enabled for external flash drives, and likewise for an external flash drive the "erase" function continued to mean a simple reformat.

Palm "Acousonde" commanding app changes

- Version 2.0d consolidates erase functions into one button
- But, 2.0.0w compatible with Palm "Acousonde" version 2.0c

Fixes

- Sampling could "secretly" quit with certain sample-rate/file-size combos
- Large log files copy correctly (without gaps) to auxiliary partition
- Greatly reduced early sampling terminations due to false power-fail detect
- New bootcode 2.0.0w fixes rare power-up into inconsistent state

Enhancements

- "Filesystem-blind" data writes during logging improve reliability and battery life
- Internal filesystem rebuilt at every boot, guaranteed consistent
- Booting much faster
- File names incorporate channel identity character and user's two-letter Site Code
- File metadata now include total acoustic path gain and anti-alias filter cutoff
- Log correctly identifies Toshiba SD hardware (including Kingston-rebranded cards)
- 30-116 kHz sample rates supported (but not as well qualified as below 30 kHz)

For acoustics-only recordings with time precision and stability.

2.0.0v incorporated over three months of testing and development. The goal was not to support full functionality, and indeed 2.0.0v still lacked three critical capabilities: sampling at rates above 29 kHz, sampling of auxiliary channels (pressure etc.), and the use of all embedded SD cards for data capacity rather than only one. Rather, 2.0.0v focused on reliability, precision, accuracy, and user friendliness to maximize dependability in the field and the clarity of resulting data.

Palm "Acousonde" commanding app changes

- REQUIRES Palm "Acousonde" version 2.0c
- Palm software allows testing of more LED behaviors
- Palm status page now reports primary storage information
- Default "erase" is quick erase, alternate erase is full/secure erase

Fixes

- Timestamps for later files no longer off by integral numbers of seconds
- User's optical time-sync marks no longer sometimes missed
- New data files recorded after reset no longer conflict with existing filenames
- Won't stop recording unintentionally due to infrared optical noise exposure
- "Monitor sync" feature better behaved and works reliably during sleep
- Fixed rare uninitialized-variable bug in FAT driver
- Delayed start begins recording at desired time, not shortly after
- Resending an accepted control program doesn't increase sampling rate
- Many error-recovery fixes/improvements for increased stability

Enhancements

- Dynamic file sizing ensures each starts no later than 1 sample after top-of-second
- Supports all sample rates up to 29 kHz (low rates still impractical due to power draw)
- Clearer user experience when using delayed-start sampling
- Shutdown of sampling on power-fail improves data safety
- Logs more details regarding built-in SD Cards
- Better logging of end-of-sampling
- Filesystem cleanup at end of sampling more thorough
- Many reliability improvements for USB Host mode
- Tighter SD card and cache behavior should improve battery longevity
- User choice of antialias bypass (or not) logged
- Bootloader 2.0.0v allows boot even in battery-low (but not dead) condition
- Updated compiler from GCC 4.1.0 to GCC 4.4.3

Supports USB connections to Windows.

Fixes

- USB Device supports Windows
- USB Device doesn't hang after several minutes on Macs
- Fixed LED flashing quirks
- FAT filenames have correct timestamps

Enhancements

- Text files use CRLF endings for DOS compatibility
- Ir-commanding erase possible when mounted as USB device
- Main oscillator discipline operation remembers discipline temperature
- Standby top-of-second LED uses high-resolution clocking if available
- Log file now available on "aux" USB partition, no need to get it via infrared