Revision 1:
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* Adjustable LCD contrast.
* Battery voltage is logged and displayed on the SAFE screen.
* Button and arming beeps can be turned off individually.
* Corrected the motor layout for 'DualCopter'. Rotation for M1 was incorrect.
* Customizable AUX switch functions.
* Fixed a bug (original FW) that forced you to go via the SAFE screen before mixer changes were reflected on the 'Show Motor Layout' screen.
* Flight mode replaced 'Self-level' on the SAFE screen and will indicate "ACRO", "SL MIX LOW/MED./HIGH" or "NORMAL SL".
* LED flashing in sync with the LVA (Low Voltage Alarm) beeps.
* No access to the Mixer Editor or the Show Motor Layout screen unless a motor layout is selected.
* The Lost Model Alarm will sound after 20 seconds (i.e. after the Auto Disarm countdown) if AUX switch pos. 1 is selected or if there is no AUX input.
* Usage warning and a disclaimer are displayed after a factory reset.


Revision 2:
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* Multiple user profiles.
* Customizable AUX switch functions (now with 5 positions).
* The Confirmation dialogue now has a header ("CONFIRM") and is also more informative.
* A confirmation beep is produced when the AUX switch is moved to a new position.
* ESC throttle calibration is now a lot safer since it will require enabling through the KK2 menu before it can be accessed.
* Camera gimbal can now be tuned and tested without arming the KK2 controller.
* Added the "SL Mixing" parameter to the Stick Scaling screen. This adjusts the stick input sensitivity in "Mixed" mode.
* SL mixing rate is now configurable. The old modes correspond to a value of 5 (LOW), 10 (MEDIUM) and 20 (HIGH).
* LED will flash rapidly for a few seconds after arming if the Low Voltage Alarm value is set too low.
* The AUX switch no longer needs to be in position #1 to trigger the Lost Model Alarm after the Auto Disarm countdown.
* Replaced the "Calibrating ESCs..." text with "ESC CALIBRATION" to make it less confusing.
* Improved button handling on the main menu. Pushing button 4 (MENU) on the SAFE screen and holding it down for too long will no longer activate a menu item.
* Fixed a problem with the Lost Model Alarm. It was not trigged after the Auto Disarm countdown if the Alarm function was assigned to AUX position 1.
* Fixed a bug in the Number Editor (original firmware) that allowed setting a value to zero (CLR) when the lower limit was higher.
* Fixed a bug causing an error message ("Sensor calibration data out of limits") to be displayed after a factory reset.
* Fixed a bug in the original firmware that kept the "Link Roll Pitch" flag from being updated until the user returned to the SAFE screen.
* Fixed a bug that affected SL P-gain when switching from mixed to normal SL mode. SL P-gain remained on its previous value instead of being reloaded.


Revision 3:
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* Quick Tuning feature added.
* M7 and M8 outputs are now controlled by using a 16 bit timer to reduce servo jitter.
* The DualCopter layout was renamed "DualCopter II" and both servos were copied to M7/M8 (reduced servo jitter).
* The TriCopter layout was renamed "Tricopter II" and a second yaw servo was added to M7 (reduced servo jitter).
* PWM output resolution increased from 555 to 625 steps on M1 to M6 and from 555 to 2500 steps on M7 and M8.
* ESCs will now be quiet while browsing the KK2 menus. This feature can be switched on/off from the Mode Settings screen.
* A small text position adjustment on the ESC calibration screen.
* Will now cut throttle if aileron or elevator input signals stop working. This change was suggested by Steveis.
* User profile selection method changed. Holding down a button will now skip through the user profiles on the SAFE screen.
* Bug fixed: Pushing the MENU button on the SAFE screen could change user profile (if the button was released too quickly).
* Bug fixed: LVA setting wasn't checked when re-arming the controller, preventing the LED from flashing if the voltage level was set too low.
* Fixed a bug in the original KK firmware: Disabling OCR1A/B interrupts using a restricted register.
* Fixed a bug in the original KK firmware: Test for ButtonDelay wasn't working correctly.
