2 Vertical Acceleration:: Select a value, and then choose whether
3 acceleration away from the ground should be above or below that
4 value. Acceleration is positive upwards, so accelerating towards the
5 ground would produce negative numbers. Acceleration during descent is
6 noisy and inaccurate, so be careful when using it during these phases
9 Ascent rate:: Select a value, and then choose whether ascent rate
10 should be above or below that value. Ascent rate is positive upwards,
11 so moving towards the ground would produce negative numbers. Ascent
12 rate during descent is a bit noisy and so be careful when using it
13 during these phases of the flight.
15 Height above pad:: Select a value, and then choose whether the height
16 above the launch pad should be above or below that value.
18 Orientation:: TeleMega and EasyMega contain a 3-axis gyroscope and
19 accelerometer which is used to compute the orientation of the
20 rocket. A record of orientations over the last 0.64 seconds is kept
21 and the largest value within this period is compared with the
22 specified value. Note that the tilt angle is not the change in angle
23 from the launch pad, but rather absolute relative to gravity—the
24 3-axis accelerometer is used to compute the angle of the rocket on the
25 launch pad and initialize the system.
29 Because this value is computed by integrating
30 rate gyros, it gets progressively less
31 accurate as the flight goes on. It should have
32 an accumulated error of less than 0.2°/second
33 (after 10 seconds of flight, the error should
36 The usual use of the orientation configuration
37 is to ensure that the rocket is traveling
38 mostly upwards when deciding whether to ignite
39 air starts or additional stages. For that,
40 choose a reasonable maximum angle (like 20°)
41 and set the motor igniter to require an angle
42 of less than that value.
45 Flight Time:: Time since boost was detected. Select a value and choose
46 whether to activate the pyro channel before or after that amount of
49 Ascending:: A deprecated configuration value which was the same as
50 setting Ascent rate > 0. Existing configurations using this will be
51 cleared and must be reconfigured by the user.
53 Descending:: A deprecated configuration value which was the same as
54 setting Ascent rate < 0. Existing configurations using this will be
55 cleared and must be reconfigured by the user.
57 After Motor:: The flight software counts each time the rocket starts
58 accelerating and then decelerating (presumably due to a motor or
59 motors burning). Use this value for multi-staged or multi-airstart
62 Delay:: Once the other parameters all become true, a timer is
63 started for the specified amount of time. While the timer is running,
64 the other parameters are checked repeatedly and if any of them become
65 false, then the pyro channel is disabled and will not fire. If the
66 timer expires and all of the other parameters have remained true for
67 the entire time, then the pyro channel is fired.
69 Flight State:: The flight software tracks the flight
70 through a sequence of states:
72 * Boost. The motor has lit and the rocket is
73 accelerating upwards. Ascent rate will be greater than zero.
74 Vertical acceleration will be greater than zero.
76 * Fast. The motor has burned out and the
77 rocket is decelerating, but it is going
78 faster than 200m/s. Ascent rate will be greater than zero. Vertical
79 acceleration will be less than zero.
81 * Coast. The rocket is still moving upwards
82 and decelerating, but the Ascent rate is less
83 than 200m/s. Ascent rate will greater than zero. Vertical
84 acceleration will be less than zero.
86 * Drogue. The rocket has reached apogee and
87 is heading back down, but is above the
88 configured Main altitude. Ascent rate will be less than zero during
89 this state. Vertical acceleration will be negative until the rocket
90 reaches a terminal descent rate, at which point Vertical
91 acceleration will be zero. Both Ascent rate and Vertical
92 acceleration are very noisy in this state, so be careful when
93 trying to use them to control pyro channels.
95 * Main. The rocket is still descending, and
96 is below the Main altitude. Ascent rate will be less than zero
97 during this state. Vertical acceleration may be briefly less than
98 zero as the rocket slows from drogue descent to main descent, but
99 it will settle down to a zero value once the rocket has reached the
100 terminal velocity under the main chute. Ascent rate and Vertical
101 acceleration should be much less noisy once the main chute has
104 * Landed. The rocket is no longer moving.
106 You can select a state to limit when the pyro channel may activate;
107 note that the check is based on when the rocket transitions *into* the
108 state, and so checking for “greater than Boost” means that the rocket
109 is currently in boost or some later state.
111 When a motor burns out, the rocket enters either Fast or Coast state
112 (depending on how fast it is moving). If the computer detects upwards
113 acceleration again, it will move back to Boost state.