+[appendix]
== System Operation
=== Firmware Modes
long). “Brap” means a long dissonant tone.
.AltOS Modes
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+ [options="border",cols="1,1,2,2"]
|====
|Mode Name
|Abbreviation
Here's a summary of all of the “pad” and “idle” mode indications.
.Pad/Idle Indications
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|====
|Name |Beeps |Description
to activate the channel. The conditions
available are:
- Acceleration:: Select a value, and then choose
- whether acceleration should be above or below
- that value. Acceleration is positive upwards,
- so accelerating towards the ground would
- produce negative numbers. Acceleration during
- descent is noisy and inaccurate, so be careful
- when using it during these phases of the
- flight.
-
- Vertical speed:: Select a value, and then
- choose whether vertical speed should be above
- or below that value. Speed is positive
- upwards, so moving towards the ground would
- produce negative numbers. Speed during descent
- is a bit noisy and so be careful when using it
- during these phases of the flight.
-
- Height:: Select a value, and then choose
- whether the height above the launch pad should
- be above or below that value.
-
- Orientation:: TeleMega and EasyMega contain a
- 3-axis gyroscope and accelerometer which is
- used to measure the current angle. Note that
- this angle is not the change in angle from the
- launch pad, but rather absolute relative to
- gravity; the 3-axis accelerometer is used to
- compute the angle of the rocket on the launch
- pad and initialize the system.
-
- [NOTE]
- ====
- Because this value is computed by integrating
- rate gyros, it gets progressively less
- accurate as the flight goes on. It should have
- an accumulated error of less than 0.2°/second
- (after 10 seconds of flight, the error should
- be less than 2°).
-
- The usual use of the orientation configuration
- is to ensure that the rocket is traveling
- mostly upwards when deciding whether to ignite
- air starts or additional stages. For that,
- choose a reasonable maximum angle (like 20°)
- and set the motor igniter to require an angle
- of less than that value.
- ====
-
- Flight Time:: Time since boost was
- detected. Select a value and choose whether to
- activate the pyro channel before or after that
- amount of time.
-
- Ascending:: A simple test saying whether the
- rocket is going up or not. This is exactly
- equivalent to testing whether the speed is
- > 0.
-
- Descending:: A simple test saying whether the
- rocket is going down or not. This is exactly
- equivalent to testing whether the speed is
- < 0.
-
- After Motor:: The flight software counts each
- time the rocket starts accelerating and then
- decelerating (presumably due to a motor or
- motors burning). Use this value for
- multi-staged or multi-airstart launches.
-
- Delay:: This value doesn't perform any checks,
- instead it inserts a delay between the time
- when the other parameters become true and when
- the pyro channel is activated.
-
- Flight State:: The flight software tracks the flight
- through a sequence of states:
-
- * Boost. The motor has lit and the rocket is
- accelerating upwards.
-
- * Fast. The motor has burned out and the
- rocket is decelerating, but it is going
- faster than 200m/s.
-
- * Coast. The rocket is still moving upwards
- and decelerating, but the speed is less
- than 200m/s.
-
- * Drogue. The rocket has reached apogee and
- is heading back down, but is above the
- configured Main altitude.
-
- * Main. The rocket is still descending, and
- is below the Main altitude
-
- * Landed. The rocket is no longer moving.
-
- You can select a state to limit when the pyro
- channel may activate; note that the check is
- based on when the rocket transitions *into*
- the state, and so checking for “greater than
- Boost” means that the rocket is currently in
- boost or some later state.
-
- When a motor burns out, the rocket enters
- either Fast or Coast state (depending on how
- fast it is moving). If the computer detects
- upwards acceleration again, it will move back
- to Boost state.
+ include::pyro-channels.raw[]
+
projects / fw / altos / blobdiff