X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=doc%2Faltusmetrum.xsl;h=fb08f5c642fa32f284ba2958a14d76a77b762794;hp=60ad118aa8df21c93cb03ddfe73105c994253fd2;hb=d24ef4aa9429f4884548e5c9fd48d57e640f0d9d;hpb=e76948d382cf6980c3a5b6c48405d71c8811780b diff --git a/doc/altusmetrum.xsl b/doc/altusmetrum.xsl index 60ad118a..fb08f5c6 100644 --- a/doc/altusmetrum.xsl +++ b/doc/altusmetrum.xsl @@ -2009,22 +2009,112 @@ NAR #88757, TRA #12200 time, and would of course appreciate customer feedback on performance in higher altitude flights! + +
+ APRS TeleMetrum v2.0 and TeleMega can send APRS if desired, and the interval between APRS packets can be configured. As each APRS packet takes a full second to transmit, we recommend an interval of at least 5 seconds to avoid consuming too much - battery power or radio channel bandwidth. + battery power or radio channel bandwidth. You can configure + the APRS interval using AltosUI; that process is described in + the Configure Altimeter section of the AltosUI chapter. + + + AltOS uses the APRS compressed position report data format, + which provides for higher position precision and shorter + packets than the original APRS format. It also includes + altitude data, which is invaluable when tracking rockets. We + haven't found a receiver which doesn't handle compressed + positions, but it's just possible that you have one, so if you + have an older device that can receive the raw packets but + isn't displaying position information, it's possible that this + is the cause. + + + The APRS packet format includes a comment field that can have + arbitrary text in it. AltOS uses this to send status + information about the flight computer. It sends four fields as + shown in the following table. + + + Altus Metrum APRS Comments + + + + + + + + Field + Example + Description + + + + + 1 + L + GPS Status U for unlocked, L for locked + + + 2 + 6 + Number of Satellites in View + + + 3 + B4.0 + Altimeter Battery Voltage + + + 4 + A3.7 + Apogee Igniter Voltage + + + 5 + M3.7 + Main Igniter Voltage + + + +
+ + Here's an example of an APRS comment showing GPS lock with 6 + satellites in view, a primary battery at 4.0V, and + apogee and main igniters both at 3.7V. + + L6 B4.0 A3.7 M3.7 + + + + Make sure your primary battery is above 3.8V, any connected + igniters are above 3.5V and GPS is locked with at least 5 or 6 + satellites in view before flying. If GPS is switching between + L and U regularly, then it doesn't have a good lock and you + should wait until it becomes stable. + + + If the GPS receiver loses lock, the APRS data transmitted will + contain the last position for which GPS lock was + available. You can tell that this has happened by noticing + that the GPS status character switches from 'L' to 'U'. Before + GPS has locked, APRS will transmit zero for latitude, + longitude and altitude.
Configurable Parameters Configuring an Altus Metrum altimeter for flight is very - simple. Even on our baro-only TeleMini and EasyMini boards, the use of a Kalman - filter means there is no need to set a “mach delay”. The few - configurable parameters can all be set using AltosUI over USB or - or radio link via TeleDongle. + simple. Even on our baro-only TeleMini and EasyMini boards, + the use of a Kalman filter means there is no need to set a + “mach delay”. The few configurable parameters can all be set + using AltosUI over USB or or radio link via TeleDongle. Read + the Configure Altimeter section in the AltosUI chapter below + for more information.
Radio Frequency @@ -2040,6 +2130,35 @@ NAR #88757, TRA #12200 frequency to successfully communicate with each other.
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+ Callsign + + This sets the callsign used for telemetry, APRS and the + packet link. For telemetry and APRS, this is used to + identify the device. For the packet link, the callsign must + match that configured in AltosUI or the link will not + work. This is to prevent accidental configuration of another + Altus Metrum flight computer operating on the same frequency nearby. + +
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+ Telemetry/RDF/APRS Enable + + You can completely disable the radio while in flight, if + necessary. This doesn't disable the packet link in idle + mode. + +
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+ APRS Interval + + This selects how often APRS packets are transmitted. Set + this to zero to disable APRS without also disabling the + regular telemetry and RDF transmissions. As APRS takes a + full second to transmit a single position report, we + recommend sending packets no more than once every 5 seconds. + +
Apogee Delay