Compensate periodic USB disconnects of TEMPer

README.md

@@ -5,6 +5,11 @@ Creates Munin graphs from the data delivered from an attached TEMPer USB Thermom
 For data collection the `pcsensor` utility is needed (by default it resides in */usr/local/bin/*), it can be obtained in source or binary form from different places like [here](https://github.com/jeroensteenhuis/pcsensor).
 Script was tested with pcsensor version 1.0.1.
 
+"USB disconnect, device number X"
+---------------------------------
+
+If you are querying your TEMPerV1.4 device periodically every 5 minutes (I assume), it disconnects from USB bus every 85 minutes (or every ~17 queries) and is instantly reconnected and detected by the kernel. This script compensates this by a retry after a second after a failed invocation of `pcsensor`.
+
 Install
 -------
 

pcsensor

@@ -18,6 +18,10 @@ if [ "${1}" = "config" ]; then
 	echo "temp.label temperatue"
 	echo "temp.type GAUGE"
 else
-	echo -n "temp.value "
-	${PCSENSOR} -cm | head -n1
+	TEMP=`${PCSENSOR} -cm`
+	if [[ $? != 0 ]]; then
+		sleep 1
+		TEMP=`${PCSENSOR} -cm`
+	fi
+	echo "temp.value $TEMP"
 fi