#Vex limit switch arduino how to#
#Vex limit switch arduino serial#

Once the board has read the input, make it print this information back to the computer as a decimal value. You can accomplish all this with just one line of code: Call this variable sensorValue, and set it to equal whatever is being read on digital pin 2. Since the information coming in from the switch will be either a '1' or a '0', you can use an intdatatype. The first thing you need to do in the main loop of your program is to establish a variable to hold the information coming in from your switch.

This is a digital input, meaning that the switch can only be in either an on state (seen by your Arduino as a '1', or HIGH) or an off state (seen by your Arduino as a '0', or LOW), with nothing in between. When your button is pressed, 5 volts will freely flow through your circuit, and when it is not pressed, the input pin will be connected to ground through the 10k ohm resistor. Now that your setup has been completed, move into the main loop of your code. Next, initialize digital pin 2, the pin that will read the output from your button, as an input:

#Vex limit switch arduino serial#

In the program below, the very first thing that you do will in the setup function is to begin serial communications, at 9600 bits of data per second, between your board and your computer with the line: That's why you need a pull-down resistor in the circuit. This is because the input is 'floating' - that is, it doesn't have a solid connection to voltage or ground, and it will randomly return either HIGH or LOW. If you disconnect the digital i/o pin from everything, its reading may change erratically. When the button is closed (pressed), it makes a connection between its two legs, connecting the pin to 5 volts, so that the pin reads as HIGH, or 1. When the pushbutton is open (unpressed) there is no connection between the two legs of the pushbutton, so the pin is connected to ground (through the pull-down resistor) and reads as LOW, or 0. Pushbuttons or switches connect two points in a circuit when you press them. The other leg of the button connects to the 5 volt supply. That same leg of the button connects through a pull-down resistor (here 10k ohm) to ground. The third wire goes from digital pin 2 to one leg of the pushbutton. The first two, red and black, connect to the two long vertical rows on the side of the breadboard to provide access to the 5 volt supply and ground. Hardware RequiredР”Р„ momentary switch, button, or toggle switchР”В¬onnect three wires to the board.

#Vex limit switch arduino how to#

This example shows you how to monitor the state of a switch by establishing serial communication between your Arduino and your computer over USB.