document what the 'Age' value in the AltosUI display means

[fw/altos] / doc / altusmetrum.xsl

diff --git a/doc/altusmetrum.xsl b/doc/altusmetrum.xsl
index b2677a029ed9c66f3c33b3861fddb0382ece3ee0..0fd19e60639eb40bd98c3c5a0c108243d147e422 100644 (file)
--- a/doc/altusmetrum.xsl
+++ b/doc/altusmetrum.xsl
@@ -277,6 +277,19 @@ NAR #88757, TRA #12200
       apogee and main ejection charges.  All Altus Metrum products are 
       designed for use with single-cell batteries with 3.7 volts nominal.
     </para>
+    <para>
+      The battery connectors are a standard 2-pin JST connector and
+      match batteries sold by Spark Fun. These batteries are
+      single-cell Lithium Polymer batteries that nominally provide 3.7
+      volts.  Other vendors sell similar batteries for RC aircraft
+      using mating connectors, however the polarity for those is
+      generally reversed from the batteries used by Altus Metrum
+      products. In particular, the Tenergy batteries supplied for use
+      in Featherweight flight computers are not compatible with Altus
+      Metrum flight computers or battery chargers. <emphasis>Check
+      polarity and voltage before connecting any battery not purchased
+      from Altus Metrum or Spark Fun.</emphasis>
+    </para>
     <para>
       By default, we use the unregulated output of the Li-Po battery directly
       to fire ejection charges.  This works marvelously with standard
@@ -481,7 +494,7 @@ NAR #88757, TRA #12200
       <para>
         You can monitor the operation of the radio link by watching the 
         lights on the devices. The red LED will flash each time a packet
-        is tramsitted, while the green LED will light up on TeleDongle when 
+        is transmitted, while the green LED will light up on TeleDongle when 
         it is waiting to receive a packet from the altimeter.
       </para>
     </section>
@@ -756,6 +769,15 @@ NAR #88757, TRA #12200
             incorrect data from being reported.
           </para>
         </listitem>
+        <listitem>
+          <para>
+            The age of the displayed data, in seconds since the last 
+           successfully received telemetry packet.  In normal operation
+           this will stay in the low single digits.  If the number starts
+           counting up, then you are no longer receiving data over the radio
+           link from the flight computer.
+          </para>
+        </listitem>
       </itemizedlist>
       <para>
         Finally, the largest portion of the window contains a set of
@@ -2199,7 +2221,7 @@ NAR #88757, TRA #12200
        </listitem>
        <listitem>
          <para>
-           RF interface for battery charging, configuration, and data recovery.
+           RF interface for configuration, and data recovery.
          </para>
        </listitem>
        <listitem>