Overview

This project introduces how to send a message from the GR-COTTON board using a USB cable.

cotton-sp-KurumiWriter-hello


Preparation

You will need GR-COTTON and a USB cable (Micro B type).

Make sure the white jumper on the reverse side of GR-COTTON is moved to the “3V3 USB” side. If it is set to the BATT side, remove and reinsert it into the USB side.

cotton-sp-prepare
cotton-sp-prepare

Hello World

GR-COTTON uses a USB cable to send a message to your computer. The sample below demonstrates how to display a repetitive “Hello World” message.

Try changing “Hello World” to something else.

    
    #include <arduino.h>
    
    void setup() {
      Serial.begin(9600);
    }
     
    void loop() {
      Serial.println("Hello World");
      delay(500);
    }
    
    

How to Display Messages

This describes messages displayed in a serial monitor.

The figures below show where to click on KurumiWriter and IDE for GR, respectively.

(Kurumi Writer)

cotton-sp-KurumiWriter-hello

(IDE for GR)

cotton-sp-ide4gr-void

gr-cotton-sp-hello-world-ide4gr-serial


Send a Message Indicating Temperature

GR-COTTON is equipped with an MCU featuring a built-in temperature sensor.

The program below sends a message indicating the temperature measured by the sensor.

    
    #include <arduino.h>
    
    void setup() {
      Serial.begin(9600);
    }
     
    void loop() {
      Serial.println(getTemperature(0));
      delay(500);
    }
    

Variable Values

This sketch displays the variable values being used.

The sample displays decimal, hexadecimal and binary, separated by tabs.

    
    #include <arduino.h>
    
    void setup() {
      Serial.begin(9600);
    }
      
    void loop() {
      static int i = 0;
      Serial.print(i); // decimal
      Serial.print("\t"); // tab
      Serial.print(i, HEX); // hex
      Serial.print("\t"); // tab
      Serial.print(i, BIN); // binary
      Serial.println(); // line feed
      i++; 
      delay(100);
    }