Arduino club

1. Arduino club What we’re really doing

2. basics The setup() and loop() functions

3. void setup() • Like the main() you’re used to • For setting pin modes • pinMode(pinNumber,MODE); • MODE can be ‘INPUT’ or ‘OUTPUT’ • pinNumber is the number of the pin • Useful to start serial connection here • Serial.begin(9600); • Only run once, when the arduino board powers on

4. void loop() • Also like main() • This is where you put your actual program • This loops until the board loses power, or breaks

5. Controlling pins But I want to make my LED flash! D:

6. digitalWrite() • Basically, turns things on and off • digitalWrite(pinNumber,STATE); • pinNumber can be any pin that was set, in the the setup, to be an output • STATE can either be ‘HIGH’ or ‘LOW’ (on or off)

7. digitalRead() • Checks if inputs are high, or low • digitalRead(pinNumber) • pinNumber can be any pin that you set as an INPUT in the setup loop • Will return either HIGH or LOW

8. delay() • Pauses the program for a set amount of time • delay(time); • Time is in milliseconds, so 1 second would be delay(1000)

9. Wiring Make sure you don’t blow things up

10. LEDs • Require 220Ω resistor (red, red, brown)

11. Conditionals

12. "If" Statements These allow us to perform an action, if a condition is met, and otherwise perform another action #include<stdio.h> inti; void main(){ printf("Enter a number! \n"); scanf("%d",&i); if (i == 0){ printf("that number was zero \n"); } else { printf("that number was not zero \n"); } }

13. Logic Operators • == means equal to • != means not equal to • && means AND • || means OR • > means greater than • < means less than • >= means greater than or equal to • <= means less than or equal to

14. Buttons • Need to be connected to ground as well as +volts

15. Loops

16. "While" Loops These allow us to loop code indefinitely until a condition is met: #include<stdio.h> //You get the point int x = 0; //Declares x variable void main(){ //Starts main while(x<100){ //Starts while loop with condition x++; //Increases x by one printf("%d \n",x); //Prints value of x } }

17. "For" Loops • Used for performing actions a set amount of times • Also useful for looping through an ARRAY • Started by: "for (initialization, condition, increment) {(functions in here)}" • Initialization is run only once, and is usually decleration of the condition variable • Condition decides when the for loop will stop, once it is false the loop will be exited • The increment decides how the condition variable will be increased/decreased #include<stdio.h> /* includes stdio library, necessary */ void main(){ // starts main function for (int x = 0; x<100; x++){ // sets how the for loop will run printf("%d \n", x); /* prints "x" until it"s equal to 100, then stops */ } }

18. "For" Loops with Arrays We can also iterate through an array with a for loop, as shown below: #include<stdio.h> //Necessary int myNum[2]={1,3}; //Defines array int arraySize=sizeof(myNum)/sizeof(int); //Works out length of the array int i=0; //Defines i for iterating void main(){ //Starts main for(i=0;i<arraySize;i++){ //Starts for loop printf("%d \n",myNum[i]); //Outputs each field } }

19. A Note about Iterating • Iterators usually take the form of: • Variable++ • This will increase "Variable" by one every iteration • Variable-- • This will decrease "Variable" by one every iteration • We aren’t limited to this, an iterator can have any mathematic function applied to it, however these are the most common