Introduction

• This page describes how to operate a sample that displays strings on OLED using SSD1309 as an example.
• For basic information such as how to install the Arduino IDE and Arduino libraries, and how to write sketches to the board, see Quick Start Guide.

Environments and products

• This page uses the following environments and products for explanations.
  • Arduino IDE 2.3.2
  • Arduino Library v2.3.1
  • U8g2 2.34.22
  • RL78/G23-64p Fast Prototyping Board
  • SSD1309 (Operating voltage: 5V)
    • If you use SSD1309 with an operating voltage of 3.3V, you need to change the drive voltage.
    • Please see below for instructions on how to change the drive voltage.
      How to drive the board's port output to 3.3V.

Install U8g2

• Start Arduino IDE and select the library icon

• Enter "U8g2" in the library manager form, search for it, and press the "Install" button

• The "U8g2" library will be downloaded and installed in the Arduino IDE

Write a sketch

• Select「File」→「Examples」→「U8g2」→「full_buffer」→「HelloWorld」

• Change the sketch below
  • Line 159 "//U8G2_SSD1309_128X64_NONAME0_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=/ 13, / data=/ 11, / cs=/ 10, / dc=/ 9, / reset=*/ 8 );” delete the "//" part at the beginning to remove the comment

• Line 371 change "Hello World!" in "u8g2.drawStr(0,10,"Hello World!");" to "RL78/G23 and SSD1309"
• Write "u8g2.drawStr(0,20,"RENESAS!");" next line

Pin connection

• Connect the pins of RL78/G23-64p FPB and SSD1309 as shown below
  • If you are using an SSD1309 with an operating voltage of 3.3V, connect VCC to the 3V3 pin of the FPB.

■SSD1309 and RL78/G23-64p FPB pin correspondence table

SSD1309 pin	RL78/G23-64p FPB pin
CS	10
DC	9
RES	8
SDA	11
SCL	13
VCC	5V
GND	GND

■Connection diagram of SSD1309 and RL78/G23-64p FPB

Compile, upload and string display

• Compile and upload
  • Select "Upload" in the Arduino IDE will start compile and upload

• An OLED string will be displayed as shown below