Eggtimer Rocketry Eggtimer User Manual page 21

D Main Mode (0-Off, 1-Igniter, 2-Servo CCW, 3-Servo CW)
E Main Altitude <100-2000 by 100, 0 @ Apogee>
F Main On-Time <1-9, 0-Cont.> {only if Main Enable =1}
F Servo PWM <0-9> {only if Main Enable = 2 or 3}
This setting controls the Main (Channel A) deployment channel. This channel is typically used
to deploy the large "main" parachute, at a pre-programmed altitude after apogee. When set to
"0", the channel is turned off, so the other settings don't matter. When set to 1-3, the
deployment channel turns on at the altitude selected by the "Main Altitude" setting, from 100 to
2000 feet or nose-over if "0" is selected. The altitude and elapsed time of Main deployment are
recorded in the Flight Summary memory for downloading. Zeroes in these fields means that the
Main channel wasn't enabled and therefore didn't fire.
If this setting is 2 or 3, the deployment channel sends out a pulse-width modulated stream that
can control standard analog hobby servos. The amount of servo rotation is controlled by the
Servo PWM value, each tick changes the servo pulse width (nominally 1.5 ms at center) by 100
microseconds in each direction, so the total possible range of servo pulse width is .5 to 2.5 ms.
The servo pulses are sent for 3 seconds after deployment, this value is not configurable but is
more than adequate for even the slowest servos.
The effect of the settings are:
Main Enable
0
1
1
Main Enable
2
3
Note that the AUX2 channel will "shadow" CHA if you set CHA to the Igniter ("1") setting, so
if you want to provide redundancy in your deployment channel you can use AUX2 with a
suitable buffer circuit to accomplish this. AUX2 is pre-programmed to fire for two seconds.
Main On Time
n/a
1-9 secs
0
Servo PWM
0-9
0-9
Deployment Channel OFF
Deployment channel activated at Main Altitude
for Main-ON seconds
Deployment channel activated at Main Altitude
and held on continuously until Reset
Deployment channel activated at Main Altitude
in servo mode, counter-clockwise, amount of
rotation controlled by Servo PWM setting
Deployment channel activated at Main Altitude
in servo mode, clockwise, amount of
rotation controlled by Servo PWM setting
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