Arduino for ODROID-GO - Hello World
- Make sure that you've followed the Arduino setup guide.
You will write code to display “Hello, ODROID-GO” on your ODROID-GO by following this guide.
Basic code structure for Arduino
When you first run the Arduino IDE, you will see a screen like below.
That editor is called sketch, and this is your playground.
The default source code is:
void setup() { // put your setup code here, to run once: } void loop() { // put your main code here, to run repeatedly: }
There are 2 functions with some comments that let you know what it performs in the code.
We will use this simple structure.
Arduino for ODROID-GO
We're providing a library for Arduino development: odroid_go.h.
The library helps you to control the components on the board such as LCD, a lot of buttons, speaker, etc.
This library should be included first.
To prepare the board for use, it should be initialized. To initialize the board, use the GO.begin() function.
If you want to control the buttons or the speaker on the board, you have to use the GO.update() function to apply the changes from the code.
The GO.update() function isn't used in this guide since only the LCD will be used to display a simple string.
Okay, let's see the code.
#include <odroid_go.h> void setup() { // put your setup code here, to run once: GO.begin(); } void loop() { // put your main code here, to run repeatedly: }
The GO.begin() function has to be in the setup() function since its called only once.
The GO instance has not only the 2 core functions but also a lot of helper functions that let you control the components on the board.
Now, let's use the GO.lcd functions to show “Hello, ODROID-GO”.
Hello World
We will use the GO.lcd.print function to show a string.
#include <odroid_go.h> void setup() { // put your setup code here, to run once: GO.begin(); GO.lcd.print("Hello, ODROID-GO"); } void loop() { // put your main code here, to run repeatedly: }
The sketch looks fine, but the text on the LCD will be too small to see.
Let's increase the font size to 2 by using the GO.lcd.setTextSize() function.
#include <odroid_go.h> void setup() { // put your setup code here, to run once: GO.begin(); GO.lcd.setTextSize(2); GO.lcd.print("Hello, ODROID-GO"); } void loop() { // put your main code here, to run repeatedly: }
You can also change the text color with GO.lcd.setTextColor(). Change the text to green.
#include <odroid_go.h> void setup() { // put your setup code here, to run once: GO.begin(); GO.lcd.setTextSize(2); GO.lcd.setTextColor(GREEN); GO.lcd.print("Hello, ODROID-GO"); } void loop() { // put your main code here, to run repeatedly: }
Additionally, as an advanced feature, we've added a function called displayGO() which includes using several effects.
New functions introduced:
- GO.lcd.setRotation(): rotates output screen. The rotation parameter can be 0 to 7.
- GO.lcd.clearDisplay(): resets all texts on the screen.
- GO.lcd.setTextFont(): sets font style after calling this. A given font names in number.
#include <odroid_go.h> uint8_t idx; uint8_t rotate; void setup() { // put your setup code here, to run once: GO.begin(); GO.lcd.println("Hello, ODROID-GO"); delay(1000); } void displayGO() { GO.lcd.clearDisplay(); GO.lcd.setRotation(rotate + 4); GO.lcd.setCursor(30, 40); if (idx) { GO.lcd.setTextSize(1); GO.lcd.setTextFont(4); GO.lcd.setTextColor(MAGENTA); } else { GO.lcd.setTextSize(2); GO.lcd.setTextFont(1); GO.lcd.setTextColor(GREEN); } GO.lcd.print("Hello, ODROID-GO"); idx = !idx; rotate++; rotate %= 4; delay(1000); } void loop() { // put your main code here, to run repeatedly: displayGO(); }
You can verify/compile or upload a sketch from the toolbar or Sketch menu.
Also, you can use helpful shortcuts.
- CTRL-R: Verify and compile.
- CTRL-U: Upload.
Before uploading the binary, you have to select the proper port at the Tools - Port menu.
If the procedure goes well, you can see “Hello, ODROID-GO” on your device.