ifdef::altusmetrum[] ==== Main Deploy Altitude This sets the altitude (above the recorded pad altitude) at which the 'main' igniter will fire. The drop-down menu shows some common values, but you can edit the text directly and choose whatever you like. If the apogee charge fires below this altitude, then the main charge will fire two seconds after the apogee charge fires. ==== Apogee Delay When flying redundant electronics, it's often important to ensure that multiple apogee charges don't fire at precisely the same time, as that can over pressurize the apogee deployment bay and cause a structural failure of the air-frame. The Apogee Delay parameter tells the flight computer to fire the apogee charge a certain number of seconds after apogee has been detected. ==== Apogee Lockout Apogee lockout is the number of seconds after launch where the flight computer will not fire the apogee charge, even if the rocket appears to be at apogee. This is often called 'Mach Delay', as it is intended to prevent a flight computer from unintentionally firing apogee charges due to the pressure spike that occurrs across a mach transition. Altus Metrum flight computers include a Kalman filter which is not fooled by this sharp pressure increase, and so this setting should be left at the default value of zero to disable it. [WARNING] Firmware versions older than 1.8.6 have a bug which resets the time since launch to zero each time a motor starts burning. Update firmware to get the correct behavior. endif::altusmetrum[] ifdef::radio[] ==== Frequency This configures which of the frequencies to use for both telemetry and packet command mode. Note that if you set this value via packet command mode, the TeleDongle frequency will also be automatically reconfigured to match so that communication will continue afterwards. ==== RF Calibration The radios in every Altus Metrum device are calibrated at the factory to ensure that they transmit and receive on the specified frequency. If you need to you can adjust the calibration by changing this value. Do not do this without understanding what the value means, read the appendix on calibration and/or the source code for more information. To change a TeleDongle's calibration, you must reprogram the unit completely. ==== Telemetry/RDF/APRS Enable Enables the radio for transmission during flight. When disabled, the radio will not transmit anything during flight at all. ==== Limit transmit to 10mW Reduces transmit power to no more than 10mW. This is useful when operating under some UK radio regulations. ==== Telemetry baud rate This sets the modulation bit rate for data transmission for both telemetry and packet link mode. Lower bit rates will increase range while reducing the amount of data that can be sent and increasing battery consumption. All telemetry is done using a rate 1/2 constraint 4 convolution code, so the actual data transmission rate is 1/2 of the modulation bit rate specified here. ==== APRS Interval How often to transmit GPS information via APRS (in seconds). When set to zero, APRS transmission is disabled. ifdef::altusmetrum[] This option is available on TeleMetrum v2 or newer and TeleMega boards. TeleMetrum v1 boards cannot transmit APRS packets. endif::altusmetrum[] Note that a single APRS packet takes nearly a full second to transmit, so enabling this option will prevent sending any other telemetry during that time. ==== APRS SSID Which SSID to report in APRS packets. By default, this is set to the last digit of the serial number, but can be configured to any value from 0 to 9. ==== APRS Format Whether to send APRS data in Compressed or Uncompressed format. Compressed format is smaller and more precise. Uncompressed format is older, but may work better with your device. The Kenwood TH-D72 only displays altitude information with Uncompressed format, while the Yaesu FT1D only displays altitude with Compressed format. Test before you fly to see which to use. ==== APRS Offset The delay from the top of the minute before sending the first APRS packet of the minute. Coordinating values for this parameter between multiple devices can allow a single receiver to reliably receive APRS packets from multiple devices. Note that this offset only takes effect while the GPS signal is locked so that the transmitting device knows the current time. ==== Callsign This sets the call sign included in each telemetry packet. Set this as needed to conform to your local radio regulations. endif::radio[] ifdef::altusmetrum[] ==== Maximum Flight Log Size This sets the space (in kilobytes) allocated for each flight log. The available space will be divided into chunks of this size. A smaller value will allow more flights to be stored, a larger value will record data from longer flights. ==== Ignitor Firing Mode This configuration parameter allows the two standard ignitor channels (Apogee and Main) to be used in different configurations. Dual Deploy:: This is the usual mode of operation; the 'apogee' channel is fired at apogee and the 'main' channel at the height above ground specified by the 'Main Deploy Altitude' during descent. Redundant Apogee:: This fires both channels at apogee, the 'apogee' channel first followed after a two second delay by the 'main' channel. Redundant Main:: This fires both channels at the height above ground specified by the Main Deploy Altitude setting during descent. The 'apogee' channel is fired first, followed after a two second delay by the 'main' channel. Separation & Apogee:: This fires the 'main' channel when the first motor burns out and fires the 'apogee' charge at apogee. ifdef::telemetrum,telemega,easymega,easytimer[] ==== Pad Orientation Because they include accelerometers, TeleMetrum, TeleMega and EasyMega are sensitive to the orientation of the board. By default, they expect the antenna end to point forward. This parameter allows that default to be changed, permitting the board to be mounted with the antenna pointing aft instead. Antenna Up:: In this mode, the antenna (or beeper, for devices without an antenna) of the flight computer must point forward, in line with the expected flight path. Antenna Down:: In this mode, the antenna (or beeper, for devices without an antenna) end of the flight computer must point aft, in line with the expected flight path. endif::telemetrum,telemega,easymega,easytimer[] ==== Beeper Frequency The beeper on all Altus Metrum flight computers works best at 4000Hz, however if you have more than one flight computer in a single airframe, having all of them sound at the same frequency can be confusing. This parameter lets you adjust the base beeper frequency value. endif::altusmetrum[] ifdef::telegps[] ==== Logging Trigger Motion This sets the amount of motion that TeleGPS needs to see before logging the new position. Motions smaller than this are skipped, which saves storage space. ==== Position Reporting Interval The interval between TeleGPS position reports, both over the air and in the log. Increase this to reduce the frequency of radio transmissions and the length of time available in the log. endif::telegps[] ifdef::telemega,easymega,easytimer,telemetrum[] ==== Calibrate Accelerometer This opens a separate window to recalibrate the accelerometers. Follow the instructions, orienting the flight computer with the antenna end, or end opposite the screw terminals, in the case of EasyMega, first up and then down. When the calibration is complete, return to the Configure Altimeter window and save the new calibration values. endif::telemega,easymega,easytimer,telemetrum[] ifdef::telemega,easymega,easytimer[] ==== Configure Pyro Channels .Additional Pyro Channel Configuration image::configure-pyro.png[width=400] This opens a separate window to configure the additional pyro channels available on TeleMega, EasyMega and EasyTimer. One column is presented for each channel. Each row represents a single parameter, if enabled the parameter must meet the specified test for the pyro channel to be fired. Select conditions and set the related value; the pyro channel will be activated when *all* of the conditions are met. Each pyro channel has a separate set of configuration values, so you can use different values for the same condition with different channels. At the bottom of the window, the 'Pyro Firing Time' configuration sets the length of time (in seconds) which each of these pyro channels will fire for. Once you have selected the appropriate configuration for all of the necessary pyro channels, you can save the pyro configuration along with the rest of the flight computer configuration by pressing the 'Save' button in the main Configure Flight Computer window. include::pyro-channels.adoc[] endif::telemega,easymega,easytimer[]