CITRUS Sketch Reference

This reference describes libraries for writing programs for GR-CITRUS and HTTP API for controlling the web compiler. Refer to the information below when using the GR-CITRUS board for the first time.

• Sketch on Web Compiler
• Sketch Using IDE for GR

The GR-CITRUS board is compatible with Arduino Pro Mini. Most of the pin layout is the same and the libraries are used in almost the same manner. The only key difference is, in Arduino, programs are called "sketches". For simplicity, we call a program a "sketch" for GR-CITRUS as well.

Here's a little explanation about sketches. This is a simple sketch that makes one LED on the GR-CITRUS board flash.

    
    #include <Arduino.h>
    void setup(){
        pinMode(PIN_LED0, OUTPUT);
    }
        
    void loop(){
        digitalWrite(PIN_LED0, HIGH);
        delay(200);
        digitalWrite(PIN_LED0, LOW);
        delay(200);
    }
    

Arduino requires a unique description -- setup() and loop() -- to be included in the description.

The setup() function is called only once after start up. The sketch above is preparing to turn on an LED using the pinMode() library.

The loop() function is then executed repeatedly. The sketch uses the digitalWrite() and delay() libraries to make an LED flash.

Whenever creating a sketch for the GR-CITRUS board, always describe #include <Arduino.h> in the first line.

The best thing about Arduino is its extensive number of libraries. These libraries allow you to do just about anything quite easily, from making LEDs flash, to creating sounds, running motors, and connecting to a network. Check out the contents of each library by selecting LIBRARY in the above menu.

The image below describes the pin layout for the GR-CITRUS board. There are many cases where you will use the library with a pin number.

For example, the following description sets pin2 to LOW:

    
    digitalWrite(2, LOW);
    

And, the following description reads from the A0 condition:

    
    analogRead(A0);
    

    
    #include <Arduino.h>
    void setup() 
    {
        Serial.begin(9600);
    }
    void loop(){
        Serial.println("Hello");
        delay(100);
    }
    

    
    #include <Arduino.h>
    #include <servo.h> 
        
    Servo servo0;
    void setup() 
    { 
        servo0.attach(9);
        servo0.write(90);  // set servo to mid-point
    }
    void loop(){
    }
    

Feel free to go to the Renesas Engineering Community with questions, problems or comments. Other users, both veterans and newbies, are there to help!