Reply To: Mirror lockup

Forums General Questions and Comments Mirror lockup Reply To: Mirror lockup


The mirror lockup trigger is in the makeDrops sketch at line 68.

All it does is set the shutter and focus pins HIGH, wait for the pulse time and then set the pins LOW. The sketch then waits for the mirror lockup delay time.

I use a Canon camera which requires both focus and shutter to be HIGH to trigger bulb mode so I use both together for all trigger events. If your camera has different requirements change the following to suit.

cameraTriggerTime_Stop is cameraTriggerTime_Start + the trigger pulse time. The trigger pulse time is set to 50ms as default.

// activate mirror lockup
if (mirrorLockup && !aborted)
digitalWrite( cam_TrigFocusPin, HIGH );
digitalWrite( cam_TrigShutterPin, HIGH );
delay( cameraTriggerTime_Stop – cameraTriggerTime_Start );
digitalWrite( cam_TrigFocusPin, LOW );
digitalWrite( cam_TrigShutterPin, LOW );

done = false;
long unsigned startTime = millis();
while (startTime == millis()) // This makes sure we are starting at the beginning of a millisecond
startTime = millis();

while (!done)
if (millis() – startTime >= mirrorLockupDelay ) { done = true; }


  • This reply was modified 5 years, 6 months ago by Martyn.