Driving LEDs

The pyro driver transistors are quite capable of driving an LED rather than a flashbulb etc, simply connect an LED and a resistor between +V (rather than +VIg for a pyro device) and the pyro channel - you should not try and drive an LED directly from an 80C32 port - they can't handle the current. The circuit looks like:

Which value should you use for R? It depends on the current required for the LED, just use Ohm's law - for example a 20mA LED with a 9v supply, you will lose maybe a volt in the diode/transistor so 8v/20mA = 400 Ohms. Be carefull the whole flight computer pulls 40mA, LEDs are a good way to run down the battery.