Merge pull request #183 from sourcebots/ultrasound-pins

Explain analogue pins

Author: tpoomlmly

content/api/ultrasound.md

@@ -21,7 +21,7 @@ Ultrasound sensors have a maximum range of 2 metres, if objects are further than
 
 ``` python
 # Get the closest distance to the ultrasound sensor is reading.
-distance_metres = r.arduino.pins[pin].analogue_value
+distance_metres = r.arduino.pins[AnaloguePin.A0].analogue_value
 ```
 
 ### Physical

content/robots/crane.md

@@ -29,8 +29,8 @@ The layout of the [encoders](/api/encoder) are as follows:
 
 ## Ultrasound sensor
 
-The crane has one [ultrasound sensor](/api/ultrasound) pointing downwards from the magnet. The ultrasound sensor is attached to Arduino pin 0.
+The crane has one [ultrasound sensor](/api/ultrasound) pointing downwards from the magnet. The ultrasound sensor is attached to Arduino pin `AnaloguePin.A0`.
 
 ## Radio
 
-The crane robot has a [radio](/api/radio) receiver attached to the hook, which can be used to detect which container is below it.
+The crane robot has a [radio](/api/radio) receiver attached to the hook, which can be used to detect which container is below it.

content/robots/forklift.md

@@ -40,13 +40,13 @@ In addition to other sensors, the forklift also has a [microswitch touch sensor]
 
 The forklift has many [ultrasound sensors](/api/ultrasound) attached to various points in the robot, here is the layout of the ultrasound sensors:
 
-- Sensor 0: Front Left
-- Sensor 1: Front Right
-- Sensor 2: Left
-- Sensor 3: Right
-- Sensor 4: Front
-- Sensor 5: Back
+- `AnaloguePin.A0`: Front Left
+- `AnaloguePin.A1`: Front Right
+- `AnaloguePin.A2`: Left
+- `AnaloguePin.A3`: Right
+- `AnaloguePin.A4`: Front
+- `AnaloguePin.A5`: Back
 
 ## Radio
 
-The forklift robot has a [radio](/api/radio) receiver attached to its centre.
+The forklift robot has a [radio](/api/radio) receiver attached to its centre.

content/robots/physical.md

@@ -20,4 +20,4 @@ The servo will only let you move the grabber in a safe range. `-1` will open the
 
 ## Ultrasound
 
-The forklift has an [ultrasound sensor](/api/ultrasound) attached to the front of the robot. This sensor uses pin 4 as the trigger pin and 5 as the echo.
+The forklift has an [ultrasound sensor](/api/ultrasound) attached to the front of the robot. This sensor uses digital pin 4 as the trigger pin and 5 as the echo.