This tutorial includes:
What is the bind method?
In order for your code to be able to use any motor or sensor, you must specify what port that motor / sensor is currently at. The purpose of the bind method is to make this process easier.
What the bind method does:
The bind method takes in a string that represents the name of the motor / sensor you want to bind. To be specific, a constexpr char array that represents the port name.
Why does the documentation say that the bind method takes in an ev3dev::address_type ?
The reason for this, is that the ev3dev::address_type is a typedef, in other words, an alternative name for constexpr char. The other tutorials will tell you that you can use Ev3Wrap::<type>::OUTPUT_A instead of a constexpr char array. These are in fact static variables that contain the port names.
How to speed it up
When in a competition, it is often the case that you want your code to start as fast as possible, and the bind method is usually the bottleneck in most cases.
Dissecting the inner workings of the bind method
The bind method defaults its port to INPUT_AUTO if no port is specified. While this is good for debugging purposes, it is very slow as it has to search through all the ports to find the one that is not in use. The sensors can also have different communication standards, for example although both the IrSeeker and the CompassSensor uses the same i2c standard, the IrSeeker’s address defaults to the 8th byte and the CompassSensor’s address defaults to the 1st byte.
TL:DR How do you speed it up?
Manually specify the port instead of making it detect the port automatically
The Leap to V2.5.0
In Version 2.5.0, the port naming system has been updated. The bind method itself isn’t affected by this change, however, if you wanted to do
Ev3Wrap::Motor::bind(ev3dev::OUTPUT_A);
You would have to do
Ev3Wrap::Motor::bind(Ev3Wrap::Motor::OUTPUT_A);
instead. The port name definitions have been moved to Ev3Wrap::<sensornamehere>::INPUT_*, from ev3dev::INPUT_*. The main goal of this change is to make the bind method easier to use for i2c sensors. (they may have different starting bytes and driver port names)