rc ranges

640.md

@@ -135,6 +135,40 @@ And for a slow speed backwards we can use
 m1.setMotorSpeed(-50)
 ```
 
+##### Alterate speed range
+
+If you plan to move from a DC driven robot to an ESC motor powered robot then it makes sense to use the same conventions that will work on both, so you can also use the 1000 to 2000 speed range with the 640 board
+
+To get your motor going forwards at full speed you should set its speed to 2000
+
+``` python
+m1.setMotorSpeed(2000)
+```
+
+For full speed reverse you should set the speed to 1000
+
+``` python
+m1.setMotorSpeed(1000)
+```
+
+And to stop the motor we can set the speed to the mid point which is 1500
+
+``` python
+m1.setMotorSpeed(1500)
+```
+
+As before, any number between 1500 and the maximum in each direction will drive the motor at a slower speed, so for half speed forward you'd set the speed to 1750
+
+``` python
+m1.setMotorSpeed(1750)
+```
+
+and half speed in revers would be 1250
+
+``` python
+m1.setMotorSpeed(1250)
+```
+
 #### Select a Servo
 
 #### Servo control