Update servo board content

Author: 8BitJosh

programming/servos.md

@@ -6,64 +6,60 @@ title: Servos Board API
 Servos Board API
 ================
 
-The `servo_board` object is used to control a collection of Servo Boards.
+The kit can control multiple servos.
+One servo board can control up to 12 servos.
+See the [Servo Board](/docs/kit/servo_board) hardware page for more details about this board.
 
-When a single Servo Board is connected to your robot, you can control it
-using the `servo_board` object.
 
-~~~~~ python
-R.servo_board.something...
-~~~~~
-
-The serial number of each detected Servo Board is printed to the log when your robot starts.
-It will look something like this:
-
-~~~~~ not-code
-sr.robot3.robot INFO - Found Student Robotics Servo Board v4 - srABC1
-~~~~~
+Accessing the Servo Board
+-------------------------
 
-If you have more than one Servo Board attached, you need to specify which one you want to control. This is done using the serial number of the board. For example: if you had a board that was labelled "srABC1",
+The servo board can be accessed using the `servo_board` property of the `Robot` object.
 
 ~~~~~ python
-R.servo_boards["srABC1"].something...
+from sr.robot3 import *
+robot = Robot()
+
+my_servo_board = robot.servo_board
 ~~~~~
 
-<div class="warning" markdown="1">
-  When you have more than one servo board connected to your kit,
-  you must use `R.servo_boards` and index by serial number. This is so
-  that the kit knows which servo board you want to control.
-</div>
 
 Setting servo positions
 -----------------------
 
-Each of the twelve servo outputs can be controlled separately. The servo outputs
-are numbered 0-11, see the [Servo Board](/docs/kit/servo_board#connectors) docs
-for details of which output is which.
+Each of the twelve servo outputs can be controlled separately.
+The servo outputs are numbered 0-11, see the [Servo Board](/docs/kit/servo_board#connectors) docs for details of which output is which.
+
+This board object has an array containing the servos connected to it, which can be accessed as servos[0], servos[1], servos[2], etc.
+The servo board is labelled so you know which servo is which.
 
 The position of servos can range from `-1` to `1` inclusive:
 
 ~~~~~ python
-# R.servo_board.servos[SERVO_NUMBER].position = POS
+# Set servo 0 position to 0.2
+robot.servo_board.servos[0].position = 0.2
 
-# set servo 1's position to 0.2
-R.servo_board.servos[1].position = 0.2
-
-# Set servo 2's position (on the Servo Board with serial number srABC) to -0.55
-R.servo_boards["srABC"].servos[2].position = -0.55
+# Set servo 2 position to -0.55
+robot.servo_board.servos[2].position = -0.55
 ~~~~~
 
 You can read the last value a servo was set to using similar code:
 
 ~~~~~ python
-# get the last setting of the second servo on the first Servo Board
-last_setting = R.servo_board.servos[1].position
+# Print the last setting of servo number 1
+print(robot.servo_board.servos[1].position))
 ~~~~~
 
-<div class="info" markdown="1">
-While it is possible to retrieve the last position a servo was set to,
-this does not guarantee that the servo is currently in that position.
-</div>
+Disabling servo outputs
+-----------------------
+
+Setting a position to `None` will disable an output.
+This is the state all the servo outputs are in when the board turns on, where no servo pulses are being sent to the outputs.
+
+~~~~~ python
+# disable servo output 5
+robot.servo_board.servos[5].position = None
+~~~~~
 
 [How the set position relates to the servo angle](#ServoAngle) {#ServoAngle}
 -----------------------------------------------