There is no doubt that you will want to put everything together and get the programming lines, but before you start, we suggest that you go over some basic principles that you will find useful later.

 What is a robot?
The word “robot” comes from the Czech “robota” (“work, work, chore”). The word was introduced in 1920 by the Czech writer Karel ÄŒapek´s in the play “Rossum's Universal Robots”, first performed in 1921. Although Karel ÄŒapek is often considered the inventor of the word , he himself designated his brother Josef, painter and writer, as the real inventor.

 We often imagine a robot as a machine with a human form, which walks, which speaks and makes gestures ... but in reality, it is much simpler.

 "A robot is a" programmable "automatic machine that can interpret information from its physical environment to adapt its behavior. It has the ability to interact with the environment and perform different functions accordingly ... "

 All robots have three types of components:
Control system: such as a controller card.
Sensors: they can read information about the environment or the robot itself.
Actuators: they have an effect on the environment or the robot.

 If we compare robots with humans, the sensors would be our senses. They send information to the control system (the brain) and we change our behavior and our environment through actuators (body parts). A robot must also have a source of energy to function and a physical structure to support the elements of which it is made.

 The control system: the controller card
The brain or the controller board is like a small computer. It is in fact a microcontroller which can be connected to sensors and actuators (muscles, voice, etc.).

 The ZUM card is made up of the following elements:
Microprocessor: The microchip performs all the operations necessary to make your card operational with your program.
Digital inputs: They can only have two values: 0 or 1 (all or nothing, On or Off).
Analog inputs: They can have multiple values: 0, 1, 34, 255, etc.
Micro-USB input: The ZUM card communicates with your computer via this port.
Battery input: The electronic card receives energy from the batteries or the power supply unit so that it can function.
Bluetooth: It allows the electronic card to communicate wirelessly with a computer, smartphone or other devices.
ON / OFF button: It cuts off the power to your electronic card so that you can program the robot without the risk of it starting to work.
Voltage regulators: They adapt the supply voltage to make it equal to that of the electronic card: 5V.
The sensors
A sensor is simply an electronic component that sends a greater or lesser amount of electricity depending on a physical element, such as light, sound or distance, etc. To connect a sensor to your electronic card, you must first check if the sensor is digital or analog.

 A digital sensor
A digital sensor can only have two values: 0 or 1, all or nothing. For example, a button is a digital sensor, which can either have the value 1 or have the value 0 when pressed or not. On the ZUM or similar electronic card, the digital sensors will be connected to the digital pins D0 to D13.

 IMPORTANT: Digital pins 0-> RX and 1-> TX are used to send and receive data, so if you connect them to a sensor or an actuator, the program of the electronic card could not be loaded, or it could not not working properly - Also, because of the D13 LED, the D13 pin does not receive the same voltage, which could cause you problems when using certain elements. Use these pins with caution.

 An analog sensor
An analog sensor can have multiple states and it is able to transform the amount of light, temperature or other physical elements into a value between 0 and 1023. To give an example with a light sensor, it is gives a smaller or larger value relative to the amount of light received. On a ZUM or similar electronic card, the analog sensors will be connected to the analog pins A0-A5.

 The actuators
An actuator is an electronic component that can act on the surrounding environment. For example, a motor that moves a wheel, a light emitting diode that indicates that the device is on, a speaker that emits a warning sound, etc.

 Using a ZUM or similar electronic board, the actuators we use will be connected to a digital pin. Some actuators, such as LEDs, can only have two states, while others, such as servo motors, can have multiple functions, making them analog components. For this type of actuator, our electronic card, which happens to be digital, will make use of a technique commonly used to synthesize continuous signals, called pulse width modulation or PWM. Don't worry about this for now, we'll come back to it later.

 How does a controller board think?
From time to time, it will happen that your project or your robot does not work as you expected. Remember that your controller card is the brain of your machine, but it is much more limited than a human brain.

 A controller card…
Think (process) things one by one, it cannot do two things at once.
Think and repeat the actions very quickly, sometimes so fast that we can't even see how she does it and sometimes we have to tell her to wait a little.
She never does the things that you didn't ask her to do. You need a program to tell it to do whatever you want and give it commands one by one.
When the circuit board completes its to-do list, it usually starts again, repeating the program over and over.

 Throughout this course, you will learn about and use the sensors and actuators that will be of real use to you. Remember, the secret is not the quantity, but to understand what you got and how to use it to the full. Come back to this page whenever you have any doubts, or leave us a comment if you get stuck on something.