[3.34]
MD5: d651a4c35c65c014fa9b6cb52b825eeb
BUGFIX: Compass showed 000 when dive mode was started out of sleep mode
NEW: Support for new hardware versions (OSTC+ only)
BUGFIX: String "Höhle" was not properly shown (German version only)
BUGFIX: Digital S8 Interface could delay startup on OSTC+ S8 in rare caes

[3.33]
MD5: 2d43f4dac2c2875e1c6269df2102c8e8
BUGFIX: Time/Surface pressure Customview was missing in dive mode
BUGFIX: Some hardware versions showed pressure fluctuations when compass display was initialised

[3.32]
MD5: 448cce977c0b2971b902d32013323319
NEW: Scrubber timer. Counts down during CCR dives and gives a warning if a) timer is <30min or 
 timer < TTS of the current dive. Enable and configure in CCR/pSCR Menu. Scrubber is shown 
 in Surface Customview and in the CCR/pSCR Menu
NEW: Support for "OSTC nano" hardware
NEW: Surface GF. Shows Surface GF for instantaneous ascend to the surface. Selectable in the custom view area
CHG: Hide buttons menu for hardware where buttons are not adjustable

[3.31]
Beta release
NEW: Add Custom View with Saturation (Called "GF99" by others), Ceiling and Surface GF

[3.30]
MD5: 8316baf84e49e5f8e87b3a2dfc43f435
BUGFIX: After a power-on reset, some hardware versions would enter divemode delayed for the first dive

[3.28]
MD5: f7960ecc2f353361dcf7e598dd460cc6
BUGFIX: Compass on very old OSTC 3 hardware was inactive in the 3.27

[3.27]
MD5: 33bbe464b0d76a59dd6833167244dbe8
NEW: Quicker startup
CHG: Slightly reduce sleep mode consumption
NEW: Compass now uses much larger font for heading display, removed clutter and graphics making the compass more useful
NEW: Compass uses dedicated stopwatch. It's reset and restarted when a course is set
NEW: Temperature still shown during compass use

[3.26]
MD5: 16e150139c3b28af38b24a05f87c0b86
BUGFIX: Year in internal Time/Date menu was limited to 2024

[3.25]
MD5: 885bd199f7f25b37ed339471fe9778f2
BUGFIX: Firmware recovery for hardware versions xxxx-xx05
BUGFIX: Plain Bühlmann (non-GF) could show a stop 0min @ 0m
CHANGE: Color design updated in surface mode
NEW: Additional customview Desat/NoFly/CNS added in surface mode

[3.25] beta
MD5: fe06fc97521fb66b41d76ac7c4b25cf7
BETA release, EN, TECH, CAVE, external Interface (Can ONLY be installed on hwOS TECH OSTC!)
CHANGE: New colors in surfacemode
CHANGE: Alignment of information in surfacemode improved
BUGFIX: With straight Bühlmann a stop @ 0m was shown in certain conditions (Instead of 240' NDL time)
BUGFIX: A faulty work-around for a silicon bug did not wake-up some OSTC 2 in very rare cases (Only for CPU rev 0x05)

[3.24]
MD5: fc65c6b668dc87b36576a330f5bb3189
CHANGE: Add voltage-based battery meter for OSTC+/PLUS when inserting batteries with unknown SOC
CHANGE: Compatibility for new hardware versions
CHANGE: Language updates
BUGFIX: Release and "Update" dates fixed

[3.22]
MD5: 9a86e4c2452b55a4dc9a043fbfa1ca71
FIX: minor fix of 12h time update in dive mode
NEW: Add charge cycle counter
NEW: Add surface customview 11: NoFly, Desat and CNS
NEW: Show # of descends in Apnoe mode
CHANGE: Compatibility for new hardware versions
CHANGE: do not show the "slow" in the alternative layout
CHANGE: minor adjustment of depth position in large layout

[3.21]
MD5: 62eae67e83fd5527cc205b8acbc37bf6
FIX: Wrong release date in 3.20 showed "Update!" message prematurely
CHANGE: Compatibility for new hardware versions
CHANGE: Reduce default bottom time for simulator from 10' to 2'
FIX: BLE was on after first reboot (until sleepmode kicks in)

[3.20]
MD5: c0e1430ec55b4f22ef21fc5a71afd0e3
Bugfix: Some USB hardware version showed USB mode insetad of BLE Mode

[3.19]
MD5: 9e79db5fa4f2f72086ce83abd3ee279f
BUGFIX: Increase resolution of tissue pressure calculations to track very low pressure differences between ambient and tissue pressures
CHANGE: OSTC with mechanical (magnetic) buttons need both buttons beeing pressed to wake up
CHANGE: Support for new OSTC+ hardware with O2 sensor inputs
CHANGE: Adjust max. brightness settings
CHANGE: reset planning parameters to default values - only when entering the menu,
 thus keeping the settings between multiple calculator runs
FIX: the output of the calculation results was divided into several steps, which
 could be interrupted in cooperative multitasking. So glitches could occur in the
 screen output if e.g. the TTS switched to NDL but the deco data flag vector was
 not updated yet. Now the compilation of all calculation results can no longer be
 interrupted.

[3.18]
MD5: c1720d0eb4b59c411e4dc2fe1862403b
BUGFIX: Properly update desaturation time and tissue data after battery change (OSTC with user-replaceable batteries only)
NEW: Option to suppress non-critical warnings in dive mode
CHANGE: Do not present gas6 option in alternative layout (Switch to normal layout in order to configure the gas 6 during the dive)
CHANGE: Do not show RX portions of tank setup menu when there is no RX hardware
CHANGE: Low-level code improvements for performance

[3.17]
MD5: 7b0dd87a7b7788c947682ad9c54a72a0
NEW: Support for current hardware version of OSTC 2, plus and Sport
- a Reset Bluetooth from the Reset Menu might be required for BLE/Bluetooth 4.0 to be enabled

[3.16]
MD5: c82632f2d1efcca365f418e72b22cedc
BUGFIX: Sensor detection in OSTC plus could fail for some hardware versions
BUGFIX: calculate time/date of the end of the dive in logbook screen correctly for
 dives with a lot of surface time/many descents
NEW: Different brightness settings for dive and surface mode
NEW: minor changes in the different language versions
BUGFIX: Reduce sleep mode current

[3.15]
MD5: 9eeca2f8d4295c4b66b1aa69e04705c1
NEW:  Support for new pressure sensor type in OSTC 2 and plus
NEW: Several changes in the different language versions
CHANGE: Tweak gas use routine to work with unplanned changes (Switching to inactive gases)

[3.14]
NEW: Big dive mode menu in big layout view
BUGFIX: fix pulsing brightness in ECO on some hardware versions
CHANGE: support for internal hardware changes
CHANGE: adjust gas density parameters to match upcoming new ISO standard

[3.13]
MD5: 9c226f0171af384ac9513b64ca15c26f
NEW: Support for current hardware version of OSTC 2 and plus
FIX: Abort on unknown parameter in comm mode
CHANGE: Several small language fixes
CHANGE: increase battery safety margins for Saft (T0) and 16650 batteries (T4)

[3.12]
MD5: 610b57b2998cfe300a97eab8cd776d18
BUGFIX: Deco paramters (Saturation/Desaturation) were shown false in the logbook and surface screen (Non-GF deco mode only)
BUGFIX/CHANGE: Saturation/Desaturation parameters are moved into thier own Sub-menu (Non-GF deco mode only)
BUGFIX: Screen startup behaviour (OLED Limited Edition only)

[3.11]
MD5: 5f8c1ae3fcd7b53cafcab511656084ce
BUGFIX: Surface pressure compensation (zero meter reference) could be delayed or stuck to old reference value
BUGFIX: configuring deco gases via the mobile Apps was not possible
CHANGE: French language fixes

[3.10]
MD5: 33740da79be05490b63c4ab04298bfd9
- Hardened all USB/Bluetooth communication against data losses and timeouts
- A new Firmware Recovery Feature has been added: the currently active firmware
  can be backed-up and restored later on while other firmwares have been loaded
  thereafter. The feature is accessible via Settings -> System Settings ->
  Reset Menu -> Reboot and becomes available with the first firmware load after
  the V3.09 beta 4 (or later) is already on the unit.
- New option to acknowledge the most recent warning in dive mode (Left press -> Ackn?)
- Removed option 'ascent speed', ascent calculation is done with a fixed
  speed of 10 meters/minute now (equals the ascent speed limit by Bühlmann).
- Improved calculation accuracy of the initial ascent. Remark: this will
  have a slight impact on the resulting deco schedule compared to firmware
  3.08.
- The deco calculator now figures in the salinity setting.
- Aligned logbook and last dive summery of avg and max depth regarding
  rounding and incorporation of salinity setting.
- Done some fine-tuning of depth outputs when using imperial units (feet).
- In dive mode, sometimes the temperature was not shown any more after a
  gas change - fixed now.
- The menu system around setting up the dive mode & settings has been
  decluttered. All settings are now sorted into the groups dive setup,
  deco setup, SAC (gas needs) setup, ppO2 setup and stops & depths setup.
- There is a new option "Swap on empty" in Dive Setup -> SAC Setup.
  It is only effective if "CalcGas(B/O)" is switched on, too. If both
  options are switched on, the deco calculation will switch to another
  tank (i.e. gas) once the tank of the current gas is calculated to be
  used up.
  This function can be used to automatically calculate a contingency in
  case of running out of a deco gas, as the deco calculation will then
  continue to calculate a deco making use of the spares from the another
  gases carried. Another application is with two or more tanks holding
  the same gas (i.e. independent double configuration, side-mount), as
  the calculations will then take the cumulative amount of gas carried
  into account before raising a gas needs attention or alarm.
- Fixed the urge of the better gas hint to always favor one specific gas
  out of a set of two or more gases that have the same change depth.
- For dives done on firmware >= 3.08 the logbook will have one more page
  showing the tissue pressures and supersaturation levels as of at the
  end of dive (i.e. when surfacing).
- As long as a gas or diluent is currently selected as breathed, it can
  not be set into the lost state any more.
- When changing the battery or doing a cold start, the current CNS value
  does not get lost any more.
- During loading of a new firmware the clock will not loose time any more
  (on old firmware it became late by about 15 sec on each firmware update).
- When run from a 3.6 V battery (either replaceable or built-in), the
  surface mode timeout is now extended to 4 minutes before going to sleep
  mode. If the OSTC is run from 1.5 V disposables, the timeout remains at
  the previous 90 seconds to save on battery runtime.
- Internal improvement: the code for the internal storage system and for
  the communication system (firmware uploading, dive data downloading)
  has been re-factored to secure maintainability for the next years to come.
- Internal improvement: the scheduler for the dive mode calculation plans
  (fTTS, bailout) has been completely rewritten for better maintainability.

[3.08]
MD5: aa73b8aad928d4a827a97978027ab726
BUGFIX: "Sticky" button behaviour on some hardware versions (Only OSTC 2 (2017), TR and OSTC plus)

[3.07]
MD5: 4ee3a98b70f73c1d1aa11d5b91e2f70f
BUGFIX: Add surface part at end of dive to surface interval properly
BUGFIX: Average depth in logbook did not took salinity setting into account
CHANGE: Change color of temperature values in logbook to yellow

[3.06]
MD5: 6f6e2bf49297f359459aac2b2a90115a
BUGFIX: Hardware versions 13-xx-xx and 58-xx-xx could hang up with single-language versions of 3.03 or 3.05

[3.05]
MD5: 2fcfaa793b1bca51cb55f4e068bcd4a3

CHANGE: In the Tech version, max. ppO2 limits can now be adjusted up to 2.0 bar.
  Caution: know what you are doing! Recommended max settings are 1.4 bar for
  work gases and 1.6 bar for deco gases.
CHANGE: CCR mode diluent ppO2 versus setpoint check can be disabled now.
CHANGE: Fine tuning of the better gas cue behavior.
CHANGE: Improved smoothing of compass display.
NEW: Attention and warning thresholds for gas density put into the options
  table (adjustment via external software only, no mapping in OSTC menu
  as of now).
CHANGE: Renamed OC gas type 'normal' to 'work' (gas for the working phase of the
  dive). Along with this, it received a down-arrow symbol to depict it as
  a gas for use at depth, similar to the '=' symbol that was introduced some
  time ago to visually depict deco gases (imagine the horizontal lines as
  deco stops).

  EXAMPLE 1: Single gas dive:
  set gas to use as 'first' and all other gases to 'disabled'.

  EXAMPLE 2: Gas-change, extended no-stop dive:
  set gas to start with to 'first', all other gases to be used later in the dive
  to 'work' and the unused gases to 'disabled'.

  EXAMPLE 3: Deco-dive with one gas for descent & bottom phase, and deco gases:
  set bottom gas to 'first', deco gases to 'deco' and the unused to 'disabled'.

  EXAMPLE 4: Deco-dive with a deco gas used as travel gas on ascent, bottom, and deco gases:
  configure the deco gas twice: once as travel gas and once as deco dive. Set the
  same change depths for both instances and put the travel gas before the deco
  gas in the gas list (i.e: gas 1: travel, gas 2: work (bottom) gas, gases 3-5:
  deco gases). Set the travel gas to 'first', the bottom gas to 'work', and the
  deco gases to 'deco'. Take care to adjust the pressure available on the deco gas
  which is used for travel gas, too, to the amount of gas that is planned to remain
  after having drawn the travel portion from it!

CHANGE: When ppO2 is above normal threshold, but still inside the deco max threshold, and
  the dive has not yet progressed to doing the deco stops, the ppO2 warning has been
  degraded to an attention, i.e. associated messages appear in yellow now instead of
  red as before.
CHANGE: In the simulator, the +5 minutes function can now be triggered in succession without
  needing to reopen the options menu each time.
BUGFIX: Setting the change depth of the first gas to zero caused some unintended behavior.
  This is captured now. Anyhow, since firmware 3.2 it is required to set proper change
  depths for gases and diluents, including the ones set as 'first'!
CHANGE: The deco calculator now automatically picks the best gas suitable for the set bottom
  depth. If no suitable gas is found (i.e. configured), calculation will be aborted with
  an error message. By this change it is possible to calculate dives that use a travel
  gas (set as 'first') and a bottom gas (set as 'work'), as the deco calculator will now
  pick the proper bottom gas for calculating the bottom segment.
  Note: the deco calculator does not calculate the descent phase but actually spends all
  of the set bottom time at bottom depth. While this puts the deco calculation results
  on the safe side, beware that the needs on the travel gas will not show up in the gas
  needs calculation results.
CHANGE: OSTC TR: The timeouts for attentions and warnings in connection with discontinued
  reception of transmitter data have been relaxed a bit:
  - For up to 2 minutes without updating the last value received will be retained.
  - After 2 minutes without reception of any updates the pressure value will be marked
    as outdated.
  - After 4 minutes without reception of any updates a transmitter will be declared lost.
CHANGE: OSTC TR: pressure logging has been implemented. Logged pressure data can be retrieved
  by downloading the logbook data using external logbook software.
CHANGE: Descent speed in the simulator has been increased from 19 to 24 meters per minute.
  This speed is not configurable, nor the simulator's ascent speed of 9 meters/min!
CHANGE: In dive mode, the battery voltage will be shown when reaching 30%, and a warning will
  be issued when the percentage reaches 25% with 1.5 Volt batteries or 15% with LiIon
  batteries.
CHANGE: Added a hysteresis to the dive start / dive end depth threshold.
BUGFIX: Bugfix in none-helium compile variant.
NEW: Added an option "extended stops" (named "Gas Change/...before 1.Stop" in Deco Setup
  -> Deco Parameters -> more). If set to YES, a gas switch will be planned immediately
  on the change depth of the gas, even if a stop on that depth is not required by deco
  constraints. When set to NO, the gas switch will be planned to be done on the next
  regular deco stop.
  With extended stops enabled and a setting of "Gas Change (time):+0'" the switch will
  be planned with no actual halt at the change depth (i.e. "switch on the fly"). With
  change time set to > 0', a dedicated stop will be placed at the change depth for the
  given number of minutes. This gas change stop may not be needed by deco constraints,
  but it will influence the following deco stop depths and times as it introduces some
  added time at depth.
CHANGE: Complete rework of the alternative dive mode screen layout.
NEW: Included RX firmware update into tech version.
CHANGE: Reworked code for ascent and deco stops calculation. Does produce different results
  compared to the code used in 3.00.3! With this implementation of an GF-controlled
  deco schedule it becomes visible when deco stops disappear due to a high GF slope
  (difference between GF low and GF high) combined with a moderate depth of the first
  deco stop.
BUGFIX: When switching between GF and aGF, the depth of the first stop (determined by GF low)
  will be recalculated now.
NEW: New tissue graphics option (compile option as of now): shows absolute tissue pressures
  (N2 + He added) and saturation per tissue. In the saturation bargraphs, the green line
  marks GF low position, the yellow line GF high and the red one 100%.
BUGFIX: GF low can not be set higher than GF high any more as such a setting would produce
  an illogical deco schedule.
BUGFIX: In case the compass is not calibrated, the heading is now displayed as "---°"
  instead of ".00°".
BUGFIX: In the surface tissue graphics, tissues whose supersaturation exceed 100% are shown
  in red color now.
CHANGE: If any tissue is beyond 100%, no desaturation and no-fly times will be shown anymore.
BUGFIX: After use of the dive simulator and the deco calculator the interim tissue desaturation
  is catched up now.
NEW: Added support for display type 2.
CHANGE: The Deco Engine has been reworked to now run for up to 700 ms each second (configurable,
  800 ms may be feasible also), split into two compute chunks per second. This increases
  reactivity to buttons presses and compass display, while boosting deco calculation turn-
  around times significantly.
CHANGE: The simulator now uses the current ambient pressure as surface pressure instead of a fixed
  1.000 hPa as done before. So in mountain diving, when being at the dive site the simulator
  will show the same NDL times and deco schedules as will be shown in a real dive.
CHANGE: When exiting the surface menu, the return to the normal surface screen has been sped up
  and the display of the power-up logo screen is skipped now also.
CHANGE: When submerged, the unit will now proceed from surface mode display to dive mode display
  without intermediate display of the power-up logos.
NEW: A cue is given when it is time to go up to th next deco stop by highlighting the next stop
  data until ascent is done.
BUGFIX: When being shallower than the indicated stop depth, i.e. because the deco needs to be
  accelerated, the reduced ambient pressure is figured in into the deco calculations such
  that the displayed stop time, TTS and gas needs do immediately reflect the reduced depth. 
BUGFIX: When set to imperial units, all depth will be shown in feet now not only in dive mode but
  also throughout the whole surface menus.
BUGFIX: When in a leap year, the 29th of February is now correctly handled when adjusting time and
  date on exactly that day.
BUGFIX: Bugfix: with the option 'always show ppO2' set, in CCR and pSCR mode a "Dil:x.xx" ppO2
  message was sometimes shown twice, once as an info and additionally as an attention or
  warning. This has been fixed now: in case of an active attention or warning the secondary
  info message gets suppressed.
BUGFIX:: the Simulator +5 min function had a punch-through effect on the real world last
  dive time (displayed surface interval).
BUGFIX: Tissue desaturation is now also computed while in surface and menu modes.

[3.01]
MD5: a54fcffc08fa50d1254a63a49fe93004

BUGFIX: Some language corrections
BUGFIX: Battery display in internal logbook
BUGFIX: Compass issues fixed

[3.00]
MD5: c227ac834f57fd831b71378cecaf2a7f

CHANGE: Battery selection menu simplified
BUGFIX: Minor language and layout corrections


[2.99]
MD5: 51307831e6874c540ceaf8708ee73c0f

- GF low can not be set higher than GF high any more as such a setting would produce
  an illogical deco schedule.

- Moved positions of the GF values in the custom view such that 100/100 can be shown
  without numbers graphically overlapping.

- The resettable stop watch shown in the compass custom view now has both of its
  digits for the seconds shown as intended.

- As it will always be unknown how much power will exactly be available from a battery,
  the threshold for a battery low warning has been rised from 10% to 30%. When in dive
  mode, the display brightness will be set to ECO upon reaching this threshold, too, to
  conserve as much battery power as possible. Anyhow, when the battery warning comes on,
  it has to be expected that the OSTC may shut down without further notice at any time
  due to depleted battery. It is therefore strongly advised to not start a dive with a
  battery reading below 50%.

- The color-coding of the ppO2 shown in the custom view has been aligned with the color-
  coding used in the ppO2 warning and attention message.

- Fixed the erratic gas needs of 999 bar when current depth is shallower than the depth
  of the currently indicated stop.

- OSTC TR: in custom view 'measured pressure / SAC / needed pressure': if needed pressure is > 400 bar,
  display will show ">400" in warning color.

- Improved detection of charging-completed.

- Gases whose ppO2 at current depth is between ppO2 max "normal" and ppO2 max deco are now color-coded
  in yellow while not in deco yet (they were colored red before).

- Faster display response when changing deco-related parameters.

- Changed color coding of current GF (supersaturation) value:

  + GF factors enabled:
    - attention (yellow) if current GF value >= GF-high value
    - warning   (red   ) if current GF value >= 100%

  + none-GF mode:
    - attention (yellow) if current GF value >=  90%
    - warning   (red   ) if current GF value >= 100%

  => Resulting overall indications when violating a stop depth (in none-GF mode, 90% is used for GF_high):

  1) When shallower than indicated stop depth but still deeper than ceiling *):   Attention on stop depth        (yellow)

  2) When shallower than indicated stop depth and shallower than ceiling:         Warning   on stop depth        (red)
     As the current GF will be >= GF-high in this situation, additionally:        Attention on current GF factor (yellow)
                                                                                  Attention on depth             (yellow, blinking)

  3) When shallower than indicated stop depth and ceiling, and outside ZHL-model: Warning   on stop depth        (red)
                                                                                  Warning   on current GF factor (red)
                                                                                  Warning   on depth             (red, blinking)

     *) In GF mode, the ceiling depth is calculated at GF-high, in none-GF mode at 100% supersaturation.


- Updated calculation of ascent time:

  + When there is a ceiling but not yet a stop obligation (deco will vanish during ascent):

      ascent time = current depth / ascent speed                                    rounded up to next full minute

  + When in deco with indicated stops:

      ascent time =    (current depth - depth of last stop) / ascent speed          rounded up to next full minute
                    +  1 minute for each meter from depth of last stop to surface
                    +  sum of all stop times

  + when in deco with indicated stop(s) and shallower than the last stop:

      ascent time =    1 minute for each meter from current depth to surface
                    +  time of the pending stop(s)

- De-cluttered and ordered dive mode custom views by topics:

   1  average depth and stopwatch         - all modes
   2  compass                             - all modes
   3  ppO2 sensors                        - CCR & pSCR only
   4  sensor check                        - CCR  mode  only
   5  pSCR data                           - pSCR mode  only
   6  tank pressure and SAC rate          - OSTC TR    only
   7  gas needs for ascent                - deco modes only
   8  gas needs for return                - cave mode  only, not yet available
   9  deco plan                           - deco modes only
  10  ceiling, current GF and tissues     - deco modes only
  11  CNS values                          - deco modes only
  12  ppO2, END/EAD and CNS               - deco modes only
  13  GF factors                          - deco modes only
  14  clock, battery and surface pressure - all modes

                                            deco modes = OC, CCR and pSCR

- Eliminated a use of the GF-high parameter in none-GF mode.

- Improved rounding of first stop depth.

- Improved calculation of NDL time.

- Improved and streamlined calculation of CNS values at end of dive.

- Improved switch-over from being within NDL to being in deco, and vice-versa. A stop time of ".." minutes will be shown
  when there is already a ceiling obligation but deco calculation reveals that it will vanish during the ascent, given
  the ascent speed limit is obeyed.

- Fixed a bug in the calculation of the initial ascent.

- Made overall deco calculations once more a little bit faster.

- Stabilized timebase for blinking of setpoint display.

- Improved handling of the condition when a bailout plan can not be computed due to no breathable bailout gas available.

- Upfixed alternative divemode screen layout handling, fixed message suppression and automatic custom view switching in
  combination with alternative layout.

- Added an option for selecting if the max. depth or the average depth shall be shown in the main divemode screen.

- Improved stability of the timebases used for calculating the average depths.

- Removed erratic NDL outputs in gauge mode.

- Fixed display of resettable dive time when it exceeds 99 minutes, 59 seconds:
  + up to  99 mins, 59 sec display shows minutes:seconds
  + after 100 mins         display shows hours:minutes

- Improved energy saving by shutting down compass and accelerometer circuitry whenever compass is not shown.

- For those that like underwater navigation with compass: when the compass is shown, the temperature display will
  be replaced by a display of the resettable dive timer.

- When configuring a manually set gas while the dive ("gas 6"), it's display will be color-coded according to the
  set O2 ratio, the current depth and the ppO2 max thresholds, the latter automatically switching between normal
  and deco ppO2 max on dive condition. After adjustment of O2 and He ratios, the gas can be finally taken by
  selecting the "gas: xxx" item from the menu.

- The better gas cue is now also given when switching while the dive to the manually set gas ("gas 6"). As long as
  there is a regularly configured gas or diluent that fits for the current depth, a cue will be given towards this
  regular gas/diluent. This cue can be suppressed by setting the cued gas/dil as lost.

- The tissue graphics in dive mode now also displays the number of the leading tissue whenever the current gradient
  factor is > 0% or when in deco. (remaining todo: there is a light flicker in the output)

- Reworked the way the current firmware version and status (beta, release) is displayed, removed the "SP" notation.

- Known limitation: after 18 hours, 12 minutes and 16 seconds of dive time:
  + The average depths will show erroneous values.
  + The resettable dive time will wrap around to 0.

[2.98]
MD5: f00ba50eb1e4ff7927aa0ec16a640b0b

- Stable Version -
BUGFIX: "lost gas" was re-activated in rare cases
BUGFIX: Internal deco planner did not display results in imperial units
BUGFIX: CNS display was out of scale (much too high) for some cases in the logbook
BUGFIX: pSCR ppO2 fixed
CHANGE: Battery names in "New Battery" menu (OSTC Plus and OSTC 3 only)


[2.97]
MD5: ec864820ee576841a2805227d7b39a99

- Stable Version - SP1
BUGFIX: Re-enable Sensors after sleep in PSCR mode
BUGFIX: handle two deco gases configured to the same change depth
CHANGE: minor italian translation update
CHANGE: Sync safety stop countdown output with divetime

[2.97]
MD5: 2f97a168530d2c86a43bbe382dde92ad

- Stable Version -
NEW: On-the-fly Gas needs calculations for all active gases
NEW: Internal deco calculator shows deco plan and gas beeds for Bailout case
NEW: CNS now, CNS in xx minutes, CNS if bailout plan is used and CNS when surfaced (Including all deco stops) is shown
NEW: Bailout TTS is computed in CCR mode (optionally) with gas needs for all bailout gases and all deco stops
NEW: Warning if an isobaric counter diffusion occurs (also in internal planner)
NEW: Warning "X-ZHL16-X" if deco model is used beyond theoretical limits
NEW: Show "Deco Zone" if we are in deco and at least one tissue is off-gassing
CHANGE: Internal deco routines heavily optimised for speed and code size
CHANGE: Limit button sensitivity to 80%
BUGFIX: Auto-Gain for newer compass versions did not work (Which decreased accuracy of heading)
CHANGE: Make disabled gases darker in surface mode (Common issue for color-blind divers)
CHANGE: French and Italien language updates
NEW: Independent saturation/desaturation multipliers for GF and non-GF Deco modes
CHANGE: Non-updated values are shown in dark blue (e.g. after a gas change) until values are valid again
CHANGE: USB OSTC (OSTC 3 and OSTC cR) will enter USB mode from Menu only

[2.27]
MD5: fc46b26261869dc6694fe3978766308e

- Stable Version -
BUGFIX: Display of negative (°C) water temperatures
NEW: One dezimal for water temperatures below 10°C
BUGFIX: Battery handling in OSTC Plus hardware

[2.26]
MD5: 4d547332a9feceeb1a528fefbc9279ed

- Stable Version -
BUGFIX: O2 Sensor readings were not updated in fixed setpoint mode
CHANGE: Minor logbook layout fix
BUGFIX: "lost gas" showed current set of gases (Diluents in CC, OC in Bailout) for both "lost gas" menus
NEW: Show Compass calibration results in Compass menu
BUGFIX: Simulator in CC mode
BUGFIX: Changing the dive mode and starting the simulator (without leaving the menu first) caused false calculations in the simulator
BUGFIX: PSCR Mode "OC Gases" showed Diluents, not OC gases
BUGFIX: CCR Mode ("First Diluent") was chosen based on OC "First Gas" number
CHANGE: CCR Calibration gas range limited to O2% 21-25 and 95-100 to save button presses
NEW: Show a warning for each sensor if the sensor is end-of-life after calibration (Less then 8mV in Air at sea level)
CHANGE: Minor optimizations
BUGFIX: Lost Diluent now possible in CCR and PSCR mode
NEW: ppO2 blinks in sensor mode when min/max boundaries are hit
CHANGE: Show actual GF (Not relative) in custom views in dive mode
BUGFIX: Do not check ppO2 for disabled gases
CHANGE: Apply safety margin parameters to both models (GF and non-GF)
BUGFIX: Impossible fixed-ppO2 (e.g. 1,6bar in 3m) used for tissue calculations
BUGFIX: Menu tree cleaned up (Exited to CCR menu from simulator settings)
BUGFIX: Do not show GF in divemode for non-GF deco mode
BUGFIX: Skip MOD Test for CCR in Sensor modes (OSTC cR and OSTC3 only)
CHANGE: Swap positions of ppO2(O2) and ppO2(Dil) in customview 10 on screen: "left = lean" and "right = rich"
BUGFIX: A wrong configured gas was suggested as "Better gas" on the configured depth even if this resulted in a ppO2 high or low condition
BUGFIX: O2 as diluent in CCR caused wrong calculations (Deco, EAD, END) in less then 6m depth
BUGFIX: Ignore "Toggle GF" Menu entry (in divemode) when using the non-GF deco mode
BUGFIX: Minor dive mode layout fixes in CCR Mode
CHANGE: Minor German language fixes
NEW: Warning for Diluent beeing out of safe ppO2 range in CCR modes
NEW: New Customview 9 in OSTC cR or OSTC3 shows mV readings after Sensor calibration
NEW: Third and fourth logbook page per dive showing Gaslist and Setpoints in standard font size
BUGFIX: several minor graphic issues in logbook fixed
BUGFIX: Rare button issues in OSTC Plus hardware
BUGFIX: Compass sensitivity for newer models
BUGFIX: PSCR mode showed bailout gaslist instead of diluent gaslist
BUGFIX: PSCR mode "Better Gas" showed bailout gases instead of diluents
NEW: More customviews in surface mode for PSCR mode
NEW: Last Dive customviews in surface mode with divetime, depth and interval
BUGFIX: Reset to MOD in Diluent Menu did reset Setpoint change depth
NEW: Two ppO2 max settings. One for travel/bottom and one for deco gases

[2.15]
MD5: 1644ab15225c01e2f2e772044f6221b5

- Stable Version -
NEW: Deep Sleep mode for OSTC Plus and OSTC 2 (2017) (Entered automatically)
NEW: Logbook detail page in larger font (And nicer layout)
CHANGE: Sleep mode current slightly reduced for all hwOS devices
NEW: Logbook now records battery information
NEW: Markers in internal logbook drawn as small "m" next to the profile

[2.13]
MD5: a1f5efe559530da84074ebf9b513046f

- Stable Version -
BUGFIX: Layout fixes in Gauge mode (German and French language only)

[2.12]
MD5: 426cb47b7e79b5b6da6a50e82693440b

- Stable Version -
CHANGE: Indicate "Bailout" for bailout deco plan in internal deco planer
CHANGE: Easier to understand "New Battery" menu (OSTC model dependent)
BUGFIX: Minor layout corrections in imperial units dive screen
NEW: New Customview 11 in dive mode shows ppO2, EAD/END and CNS
CHANGE: Customview 4 shows Clock, Battery Information and Tissue Information
CHANGE: Show warnings either in Customview (If active) _or_ next to warning sign
NEW: Show battery type in information menu (T0:1.5V AA, T1:3.6V AA, T2:3.6V/0.8A LiIon, T3:Internal 18650, T4:Internal 16650)
NEW: Show battery type in surface mode next to battery voltage

[2.10]
MD5: 00d22d2b2aff7dac331d40a278a7b496

- Stable Version -
NEW: Adjustable timeout for Divemode
CHANGE: Firmware now split in two variants (EN/DE) and (FR/IT)
NEW: New battery option for AA 3,7V rechargable (For OSTC 3)
NEW: Show Uptime (Time since last firmware boot) in information menu
NEW: Store more battery info into logbook memory
BUGFIX: Minor text alignment fixes


[2.09]
MD5: d4aa68d2c418852adbdb57a5538f500b

- Stable Version -
BUGFIX: Compatibility with "hwOS Config" fixed
NEW: New hardware descriptor command 0x60 added (For PC programs)

[2.08]
MD5: 1d8b13d8ed4ae52326a521471407532f

CHANGE: Logbook marker temporally disabled in internal logbook
BUGFIX: Characters with descenders were not drawn correctly in rare cases
NEW: Support for different compass chip (Internal hardware change)
CHANGE: Language fixes

[2.07]
MD5: 9b2f71a511890dad0e5624067354a6fb

Release version for new OSTC2 (Minor internal hardware changes)
CHANGE: Remove ppO2 [Dil] from OC dive mode screen

[2.05]
MD5: 8e73ae695057856502b42e431c571d2d

- Stable Version -
NEW: Support for new logbook memory chip (minor hardware change)
BUGFIX: Button sensitivity was not reset after update in some cases

[2.04]
- Beta Version -
NEW: New Customview shows ppO2(O2) and ppO2(Diluent) during CCR mode

[2.03]
MD5: 89e0bc9bd949588e3f1845efdd9dfe1c

- Stable Version -
BUGFIX: Fix missing ccr setup menu (From 2.02)

[2.02]
MD5: 234a56fb8b9add06a9c6344dfbfe2579

- Stable Version -
BUGFIX: Fix rare issue after battery change (OSTC3 did not start properly)

[2.01]
MD5: f7908ef65e0637a0d54de4f499b3b3db

- Stable Version -
BUGFIX: Divetime >99mins was not displayed (Only OSTC2 with serial > 10500)
BUGFIX: Minor layout fixes in divemode (Dynamic gaslist and stopwatch)
BUGFIX: Minor language updates

[2.00]
MD5: e01ad26895b65097605af33e95089211

- Stable Version -
NEW: Logbook marker can be set in dive mode menu (OC only)
NEW: Logbook shows markers with small orange boxes in the profile
NEW: "Lost Gas" feature allows disabling gases during the dive
CHANGE: Show velocity from 5m/min or more (Ascend or descent)
BUGFIX: Make sure SP1 is always selected on start in Auto-SP mode
CHANGE: New segmented speed graph in divemode
NEW: Safety Stop can be configured (Start-, End- and reset-depth + length of stop) via PC

[1.93]
MD5: a0ee9c3854b68916445cfe62144bd157

- Stable Version -
BUGFIX: minor text allignment in CCR mode
CHANGE: fix timing issues during Bluetooth download (Bluetooth models only)

[1.92]
MD5: c99ef3ef813aba656a67929aa785698b

- Stable Version -
CHANGE: Logbook now shows end-of-dive date and time for dives made with firmware <1.92 indicated by an icon in the logbook
CHANGE: Logbook shows start-of-dive date and time for dives made with firmware >=1.92
BUGFIX: Text alignment in logbook
NEW: Show actual dive count in logbook list view (If <1000)
BUGFIX: Minor language and text aligment fixes

[1.91]
MD5: 2eb16d81d1bc7087d7f8ef576118a7ef

- Stable Version -
BUGFIX: German texts in ppo2 menu were too long for screen resulting in resulting in text display issues


[1.90]
MD5: 4cb7790756da1716db3cf566fe4cca74

- Stable Version -
CHANGE: Do not show ppO2 in warning area if already shown in custom view
BUGFIX: Logbook list view for more then 100 stored dives
BUGFIX: BLE timings for MAC issues
BUGFIX: Battery consumption calculation in sleep mode (3,6V battery only)
NEW: Bearing can be set in surface mode
BUGFIX: +5min for stopwatch during simulation did not work
CHANGE: minor language updates

[1.88]
MD5: 1df606e0cbca68c691e8570334238d72

- Stable Version -
BUGFIX: Start with Sensor use from sleep (cR only)
CHANGE: Apply button settings when button menu is closed
NEW: Reset button settings on a magnet reset (cR and OSTC 2)

[1.87]
MD5: eeafcf36c60afc862f166dd66cbbff2c

- Stable Version -
NEW: Hardware support (Screen)
NEW: Additional temperature calibration via PC interface

[1.86]
MD5: 0231f20838277ed9ea4257140a3aa2bb

- Stable Version -
CHANGE: French update
BUGFIX: Rotate button sensitivity with screen (OSTC 2 and cR)
CHANGE: GF and aGF high range increased to 45-110%
NEW: New option to download "Compact Headers". Improved BLE support (OSTC 2 and OSTC 3+)
NEW: Quit Simulator automatically when starting a real dive
BUGFIX: Auto-Brightness clipped to lowest settings in bright sunlight on some devices
CHANGE: Auto SP now available on OSTC 2
CHANGE: change button sensitivity range and default (OSTC2 and cR)
NEW: MOD Warning (Can be disabled)
NEW: Depth dependent ascend speed (Can be disabled)
NEW: Graphical speed indicator (Can be disabled)
NEW: Option to always show the ppO2, shows ppO2 for Diluent in CC mode
NEW: Mode Auto SP: Automatically switches the SP during descent (CC Mode)
NEW: Deco planer computes gas consumption for all gases and can compute bailout plans for CC modes

[1.81]
MD5: 180a23d1a92b94e5da08e4c85bd42389

- Stable Version -
BUGFIX: Fix download issue for dives made with 1.80 firmware

[1.80]
MD5: 6521c3a43391386e61821bddffa0dc80

- Stable Version -
CHANGE: Automatically abort connection fail after 2mins (Bluetooth only)
BUGFIX: Fast Gas change near the ppO2 limit could cause switching to a non-available Gas #0
CHANGE: Code now called hwOS officially
BUGFIX: There was a 1:4096 chance that a portion of a dive was not stored correctly resulting in download issues

[1.78]
MD5: 77a9fdb019479976f5790cd923cd012a

- Stable Version -
BUGFIX: Increase timing tolerance for S8 HUD (cR only)
CHANGE: increase min input voltage from 1,2mV to 1,9mV (cR only)
CHANGE: adjust menu for different hardware versions (OSTC 2)

[1.77]
MD5: 7a6a606844f1533c59452dfe51ca1d8b

- Stable Version -
BUGFIX: Charge done indicator (cR and 2 Hardware)
BUGFIX: Analog sensors were ignored in 1.76

[1.76]
MD5: 76098d8f34563447853dd01a2cede108

- Stable Version -
CHANGE: aGF pair has same range then normal GF pair
BUGFIX: Always update CCR sensor data in Sensor-Menu
NEW: Graphical compass display in dive mode
NEW: Bearing option in divemode
CHANGE: New warning icon


[1.75]
MD5: b70e56f26f8b910162fbf2e637915b81

- Stable Version -
BUGFIX: Show average depth with one dezimal digit only
NEW: Show start gas in OC mode permanently
NEW: Show OSTC2-like active gas boxes in surface mode

[1.74]
MD5: 3d8df57bb7b33e735d31788de2248a59

- Stable Version -
BUGFIX: Show dives with >999mins divetime correctly
NEW: Support for optical hwHUD without the LED module (OSTC3 only)

[1.72]
MD5: d8a4dc6c3453e5cce0cabbde45e82c25

- Stable Version -
BUGFIX: Store new dives after power-loss during divemode correctly
NEW: Make button sensitivity configurable (cR hardware)

[1.70]
MD5: 5102d91240ef615dd8169e2c8bf3a15a

- Stable Version -
NEW: Show plan parameters in decoplan result page
NEW: On-board simulator can increase divetime in 5min steps
BUGFIX: Layout fixes

[1.62]

- Beta Version -
CHANGE: (Slightly) reduce current consumption in Eco and sleep mode
NEW: Allow auto-return from setpoint fallback

[1.61]

- Beta Version -
BUGFIX: O2 > 99% was not configurable from the PC
BUGFIX: Quit Apnea mode on the surface manually
BUGFIX: Check min and max values after PC configuration properly
CHANGE: Longer timeout (4 min) for calibration menu and Surface mode (CCR Modes)
NEW: Show Bailout Gas List in Surface mode (CCR Modes)
CHANGE: Faster update rate for sensor display in surface mode

[1.60]

- Stable Version -
BUGFIX: END/EAD updated when adjusting current gas during the dive

[1.54]

- Beta Version -
BUGFIX: Future TTS in sensor mode (CCR Mode)
CHANGE: Clarify Travel Gases with "---" as change depth
CHANGE: Enable "Change Depth" Menu only for deco gases
CHANGE: Draw a frame around the dive mode menu
BUGFIX: Average depth computation

[1.53]

- Beta Version -
BUGFIX: Flip compass with flipped screen, too
BUGFIX: Surface interval was paused during simulator
BUGFIX: False max. temp in Logbook, false Bailout and Gas 6 flags in logbook
CHANGE: Improve internal logbook usability
CHANGE: Compass readout smoothed

[1.52]

- Beta Version -
NEW: Safe tissue data, date and time during firmware update
CHANGE: Postion of min. and (NEW:) max. temperature in logbook
BUGFIX: Fast diluent (w/o dive mode menu) change did not work correctly

[1.51]

- Beta Version -
BUGFIX: Clear Setpoint-Fallback warning when in bailout
NEW: 180° display rotation option
NEW: Show ppO2 for change depth during gas setup
CHANGE: Re-arranged Settings Menu
BUGFIX: PC configuration issues fixed

[1.50]

Stable release

[1.46]

- Beta Version -
NEW: Setpoint-Fallback option for external O2 sensor failure

[1.45]

- Beta Version -
CHANGE: Minor German language update
BUGFIX: Clock setting (Bug from 1.44beta)

[1.44]

- Beta Version -
NEW: Update warnings every second
NEW: Show "Stop" in front of Safety Stop
BUGFIX: Start dive mode simulator in correct depth
BUGFIX: Surface interval was not displayed correctly in some cases
NEW: Store tissue load, date and time, surface interval, desat. time and nofly time every hour and reload them after battery change
NEW: Show clock in Apnea mode, minor layout changes in Apnea mode
NEW: Simplify gas change (Two button presses only)

[1.41]

- Beta Version -
NEW: Ceiling display (GF_hi based) in divemode
NEW: Support for C3 hardware
CHANGE: Show heading with leading zeros
BUGFIX: Do not show "GF info" for non-GF modes
BUGFIX: Minor display allignment changes

[1.40]

CHANGE: Minor language updates
NEW: Show a Safety Stop if enabled (Menu "Deco Parameters")
BUGFIX: dive profile recording issue in OC mode
BUGFIX: OSTC settings via USB issues
BUGFIX: CNS in deco planner

[1.30]

NEW: Show event "Bailout" in internal logbook
CHANGE: Always compute bailout plan based on all active gases
CHANGE: Re-select last diluent when returning from bailout to OC
BUGFIX: Show "*" always in front of the initial Setpoint 1

[1.26]

BUGFIX: compass calibration does now timeout automatically after 60s
BUGFIX: decoplan re-calculation in bailout case

[1.25]

BUGFIX: No average depth for end-of-dive portion (<1m)
BUGFIX: Show "CC Diluents" in logbook instead of OC Gas List
NEW: automatic compass gain makes calibration quicker
CHANGE: Battery percent setpoints adjusted to worst case current consumption

[1.24]

CHANGE: Minor french translation
CHANGE: No warning sign for selected aGF
CHANGE: Show battery warning sign for less then 10% battery capacity only
CHANGE: Color schemes improved

[1.23]

BUGFIX: Reset Logbook did not reset Logbook TOC properly

[1.22]

BUGFIX: Potential bug to freeze the OSTC3 after battery change or update

[1.21]

CHANGE: French Translations, again
BUGFIX: Fix cursor in "New Battery" menu
NEW: Show serial number and firmware version in main menu
CHANGE: "Reset all" returns to surface mode
CHANGE: Single press surfacemode menu

[1.20]

Stable release

[1.12]

BUGFIX: Maintain last selected customview in surface mode
BUGFIX: Set Day for months <31 days
CHANGE: Some French Translations
CHANGE: Default Future TTS=0 (Disabled)
NEW: Expand "gas change window" up to 1m below programmed
    change depth (If ppO2 within user-set max. threshold)
BUGFIX: Intermittent USB connection on MAC

[1.11]

NEW: allow logbook erase from reset menu
NEW: show battery voltage in info menu

[1.10]

Stable release

[1.04]

NEW: 1.6 hardware support
CHANGE: Backlight level in eco mode
BUGFIX: Display Desat.-Time >100 hours

[1.03]

NEW: user-selectable color schemes
BUGFIX: div. language corrections
NEW: Dynamic Gaslist in OC mode (Divemode, Customview 7)
CHANGE: Change "O2" warning to "ppO2"
NEW: "End-of-Dive" countdown when surfaced

[1.02]

CHANGE: Time and Date in normal (Not tiny) font
BUGFIX: Minor french language fix

[1.01]

BUGFIX: deco gas init in OC planner

[1.00]

BUGFIX: Percent display with 1,5V batteries

[0.99]

BUGFIX: alternating brightness at very low ambient light
CHANGE: GF high lowest setting 60%
BUGFIX: NOAA tables for CNS are in ATA, not bar
CHANGE: change apnea timeout, do no longer store apnea dives in logbook
BUGFIX: Simulator in CC mode
BUGFIX: Apnea total divetime
BUGFIX: Battery percent value with 3,6V battery
NEW: Surface customview with important deco settings

[0.98]

New: Add cardinal (and ordinal) directions for the compass

[0.97]

NEW: compass gain option to work with more magnetic battery types
BUGFIX: fix imperial units in logbook

[0.96]

NEW: calm compass reading for minor heading changes
NEW: reduce eco low brightness threshold (for cave diving)

[0.95]

BUGFIX: Show "MOD:" instead of "EAD:" in gas setup

[0.94]

CHANGE: Show Max. Depth with 0.1m precision

[0.91]

BUGFIX: Battery percents in cold water

[0.93]

BUGFIX: Custom text <60 chars
BUGFIX: Logbook PC protocol
Italian language updates
BUGFIX: Timeout in decoplanner result page

