KURUMI Sketch Reference

Let’s have a bit of fun creating unique gadgets with the GR-KURUMI board and web compiler provided by the Gadget Renesas project. The board comes mounted with a very small microcontroller (MCU). By programming this IC, you can make lights flash, emit various noises and trigger objects to move.

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

• My First KURUMI
• Manual for the Web Compiler

The GR-KURUMI board is compatible with Arduino. The pin layout and outline are nearly the same as Arduino Pro Mini, the small one. And the library is also nearly the same.

In Arduino, programs are called "sketches," which is why we have tried to make things easier by calling them "sketches" here as well.

Here's a little explanation about sketches. Take a look at the sample sketch below. This is a simple sketch that turns on a red LED on the GR-KURUMI board.

#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 sketch. The setup() function is called only once after reset or power-on. Then, the loop() function is executed repeatedly. For example, the sketch to the right turns the LED on and off using the pinMode(), digitalWrite() and delay() functions. The pinMode() in the setup() defines which pin to use for driving the LED. Then, the digitalWrite() turns the LED on and off. The delay() defines on and off time. When using the KURUMI board, always describe #include <RLduino78.h>, the library that includes all these Arduino compatible functions, in the first line.

The best thing about Arduino is its plentiful choice of libraries. These libraries make it easy to not only turn on LEDs, but also emit noises, run motors and connect to networks. Check out the lineup in the Library tab from the menu above.

The image below describes the pin layout for the GR-KURUMI board. There are many cases where you will use the library with a pin number. For example, the following description:

digitalWrite(2, LOW);

This means to set pin2 to LOW. And, from A0 to A7 can be used to read the analog value. For example, the following description:

analogRead(A0);

This means to read from the A0 condition. From A0 to A7 are same as from 14 to 21. And, pin22 is connected to the red LED on the GR-KURUMI board, pin23 is the green LED and pin24 is the blue.

March 30, 2018: Updated Serial and Ethernet. Added SoftwareSerial.

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

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

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