Magnetic crank trigger?

[art leong]

I run a magnetic crank trigger (not flying magnets). I use a 20 tooth steel trigger wheel (adjustable). And a 05 Honda 2 wire cam sensor (reluctor) for a pickup. My ECU reads the falling part of the signal. So I've been lining up a tooth just past the pickup magnet (about 1/4" in the center of the pickup which is .700 round). When number 1 is at TDC firing. But I have no way of checking the accuracy of my settings. I know how to set the cam sensor timing. By use a function to lock the advance at 20 degrees and dial 20 degrees into my timing light. If the timing marks don't line up I change the light till they do then put in the offset.
But I don't have this function for the crank timing.
If I could get a signal from the crank pickup to my timing light. I could get it right.
Anyone know how I could use the pickup to trigger a timing light? This way I could see exactly what position the tooth is in relation to the pickup.