Motors

Motors can be used for all sorts of things, besides just moving your robot. For instance, they could also be used as part of a mechanism to collect cubes. However you decide to use them, they’re really simple to control.

When you control motors, you can choose how much power you want to give them. This is expressed as a percentage, so 0% means a stopped motor and 100% means a motor at full power.

Note

If you have large motors you should avoid using 100% power when the motor is stalled or stationary, otherwise the rush of current may cause the robot to shut down the motor output. Instead of jumping from 0% to 100% start at a lower value such as 50% and work your way up.

If you want to spin your motors in reverse, just stick a negative sign in front of your percentage.

Python

You can control motors using the motors property of the Robot object. To set the power of the first motor to 60% use:

R.motors[0] = 60

Remember that indexes start at 0; To control the second motor instead, replace motors[0] with motors[1].

To stop both motors:

R.motors[0] = 0
R.motors[1] = 0

Here’s a more complete example:

import robot

R = robot.Robot()

# set motor 1 to 60% power
R.motors[0] = 60

# set motor 2 to 60% power in the backwards direction
R.motors[1] = -60

# turn both motors off
R.motors[0] = 0
R.motors[1] = 0

Tip

By default the BrainBox is designed to work safely with the TT motors supplied, these are 6V motors. If you choose to use motors that have a different nominal voltage, then you can specify this when initalising the robot object. For example when using 9V motors:

R = robot.Robot(max_motor_voltage=9)

We do not recommend running motors above their design voltage, it may (sometimes dramatically) shorten the lifespan of your motors. If you choose to overvolt your motors you should be prepared to swap them with spares and design your robot to ensure you have access to replace them.

Blockly

Blocks for controlling motors can be found in the Movement section. It follows a similar structure to how the python is layed out, with motors being set to a value between -100 and 100 to control their rotation speed.