publisher lesson modification

book/duckiesky_high_school/17-sac2/20-ros/20-ros-publisher.md

@@ -102,7 +102,12 @@ Navigate back to the previous terminal, run the code. We can see it is still pri
 
 Q: What about the publisher we just created?
 
-A: Open another terminal, run `rostopic list` and see the `distance` topic we just created. Then we run `rostopic info distance` to see the message type (Float32) and where it is published from (infrared_node). Lastly, run `rostopic echo distance` to show the message we just created in the terminal! (It should be Float32 messages with data label)
+A: Open another terminal, run `rostopic list` and see the `distance` topic we just created. Then we run `rostopic info distance` to see the message type (Range) and where it is published from (infrared_node). Lastly, run `rostopic echo distance` to show the message we just created in the terminal! (It should be Range messages with data label)
+
+Q: How can we show **our** calibrated value (instead of the default) on the web interface?
+
+A: According to [the operations manual](https://docs.duckietown.org/daffy/opmanual_sky/out/flight.html), before taking flight, after students start the flight code by hitting `./start`, they might hit "tick 5" to go to the infrared node and hit 'Ctrl + C' to stop it. Next, they might run their own script `python ~/ws/src/pidrone_pkg/ir.py`. Now the image shown on the web interface uses the value from the publisher they just wrote! 
+
 
 **Useful Resources and References**
 

book/duckiesky_high_school/19-sac3/20-imu/21-imu-intro.md

@@ -148,9 +148,6 @@ Pause for group discussion and presentation.
 
 A: We need sensors that interact with the outside world, such as GPS, to know the location.
 
-TODO: show these values and drone visualization in cleanflight
-
-
 **Useful Resources and References**
 
 Between times 0:21 and 5:00 of [this video](https://www.youtube.com/watch?v=whSw42XddsU).