X-Git-Url: https://zdv2.bktei.com/gitweb/EVA-2020-02.git/blobdiff_plain/2fc10824a04e0d2153705f9e9d5be33654a99493..3592a7e928008b0e89286c91aa72b4db89a50d5f:/exec/bkgpslog-plan.org?ds=sidebyside

diff --git a/exec/bkgpslog-plan.org b/exec/bkgpslog-plan.org
index 519456b..47154eb 100644
--- a/exec/bkgpslog-plan.org
+++ b/exec/bkgpslog-plan.org
@@ -26,7 +26,38 @@ when a new session is started.
 2020-07-02T18:33Z; bktei> Simplify how the output tar file's existence
 is checked and its status as a valid tar file is validated. This was
 done using a new function ~checkMakeTar~.
-** TODO Add VERSION if output tar deleted between writes
+** DONE Add VERSION if output tar deleted between writes
+
+   CLOSED: [2020-07-02 Thu 20:22]
+2020-07-02T20:21Z; bktei> Added bkgpslog-specified function
+magicWriteVersion() to be called whenever a new time-stamped ~VERSION~
+file needs to be generated and appended to the output tar file
+~PATHOUT_TAR~.
+** DONE Rewrite buffer loop to reduce lag between gpspipe runs
+   CLOSED: [2020-07-03 Fri 20:57]
+2020-07-03T17:10Z; bktei> As is, there is still a 5-6 second lag
+between when ~gpspipe~ times out at the end of a buffer round and when
+~gpspipe~ is called by the subsequent buffer round. I believe this can
+be reduced by moving variable manipulations inside the
+asynchronously-executed magicWriteBuffer() function. Ideally, the
+while loop should look like:
+
+#+BEGIN_EXAMPLE
+while( $SECONDS < $SCRIPT_TTL); do
+    gpspipe-r > "$DIR_TMP"/buffer.nmea
+    writeBuffer &
+done
+#+END_EXAMPLE
+2020-07-03T20:56Z; bktei> I simplified it futher to something like
+this:
+#+BEGIN_EXAMPLE
+while( $SECONDS < $SCRIPT_TTL); do
+    writeBuffer &
+    sleep $SCRIPT_TTL
+done
+#+END_EXAMPLE
+Raspberry Pi Zero W shows approximately 71ms of drift per buffer round
+with 10s buffer.
 * bkgpslog narrative
 ** Initialize environment
 *** Init variables