This project has been evolving for several years and is still used regularly with the depron indoor model shown below, powered by a single cell 130mAh Li-po battery and a 7mm pager motor and it includes an integral ESC using a 15A surface mount MOSFET. To save weight the timer/profiler is built in 'rats nest' fashion, so it's not worthy of a close-up view! I'm considering venturing into a full surface mount PCB version in the fullness of time.

The timer/profiler started off with a (single) button/LED user interface with 8 flight phases each of which could be set by the user:-

  1. start delay
  2. motor soft start
  3. climb power
  4. climb duration
  5. cruise power
  6. power reduction period
  7. cruise duration
  8. descent

Setting by pushbutton was time consuming and confusing, so an infra-red receiver device was added to the timer/profiler and the software revised such that all the parameters could be set using the numeric keypad of a TV remote controller (shown in the pictures above)

In the idle mode, a brief press of the button 1 to 8 associated with the desired flight phase puts the programmer into adjustment mode and the desired parameter is then entered - eg '3' selects CLIMB POWER then '8', '5' set it to 85%.

A longer press of the appropriate button puts the programmer into reporting mode and it flashes the LED to read out the current parameter value - eg a long '2' selects SOFT START and the LED flashes 3 times to show that the current setting is 3 secs. Motor power values are counted in 5's to reduce the amount of flashes.

A long press of '9' causes the LED to blink out the battery voltage from a base of 3 volts - so 7 blinks reports the battery condition as 3.7v. A low voltage cutout prevents the battery being discharged below 3.3v

The red (power) button on the remote starts a flight and it can be used to terminate a flight as the (side mounted) infra-red red sensor presents itself to the flier once per circuit. Similarly the UP and DOWN buttons can be used to tickle the power level to prevent an over enthusiastic plane climbing into the ceiling - but that's not strictly free-flight - shhhhh! 

A planned further enhancement is to compensate for the gradually declining battery voltage during a session of 9 or 10 one minute flights to maintain a consistent flight pattern.

Currently I'm working on a purpose designed programmer using an LCD display where a menu button steps through each of the flight phases in turn and a '+' and '-' button can be used to set the parameter in question.