X-Git-Url: http://challenge-bot.com/repos/?p=challenge-bot;a=blobdiff_plain;f=guide%2Fchallenge-bot.scm;h=f019671a68c73d422c60b65040032595a5a8a6c0;hp=84bbeb678210bc757358ac62d5237a4f2327c756;hb=6143e39f4fe1607ba81629185450848d5226d578;hpb=b863c7aebaa06ae08eb42d05d1f520ad3c2447e3

diff --git a/guide/challenge-bot.scm b/guide/challenge-bot.scm
index 84bbeb6..f019671 100644
--- a/guide/challenge-bot.scm
+++ b/guide/challenge-bot.scm
@@ -592,8 +592,21 @@
     (item [what kind of screw is used?])))
   (section
    :title [sonars]
-   (subsection
-    :title [deck placement])))
+   (p [we are almost done with mechanical assembly!
+          this next step is to add the sonar sensors to the robot.
+          sonar sensors are what the robot uses to detect distances.
+          it sends out a signal, then listens for a response and
+          keeps track of how long it takes.])
+   (figure
+    :legend "sonar sensors"
+    (video :file "6-sonar-sensors-to-deck.ogv"))
+   (p [check])
+   (enumerate
+    (item [are your sonar sensors pointy pins facing in toward the
+               arduino?])
+    (item [was it difficult to get the sonar into the holder?])
+    (item [what would happen if it was easy to slip the sonar sensor
+                into the sonar holder?]))))
  (chapter
   :title [wiring and software]
   (section