contrib: script to sample 20 mins of battery status from android app

contrib/app_android-battery-sampler.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+# Use wireless debugging with this script
+# Phone should be fully charged and unplugged
+
+adb root
+
+log_elapsed() {
+    now=$(date +%s)
+    elapsed=$(( now - start ))
+    volt=$(adb shell cat /sys/class/power_supply/battery/voltage_now)
+    echo $elapsed, $volt
+}
+
+start=$(date +%s)
+
+for i in $(seq 1 20); do
+    log_elapsed
+    sleep 60
+done
+
+log_elapsed
+