OLED W Click

How does it work?

OLED W Click is based on the MI9639BO-W, a 19.3×7.8mm 96x39px white light monochrome passive matrix OLED display from Multi-Inno Technology. The MI9639BO-W display features an SSD1306, a 128×64 dot-matrix OLED/PLED segment/common driver with a controller. The controller has built-in functionalities like contrast control (256-step brightness control), normal or inverse image display, vertical and horizontal scrolling functions, and much more accessible through the configurable host interface.

OLEDs are emissive and don’t require a separate backlight as LCD technology does, reducing the OLED display’s overall power consumption compared to LCDs. It also does not suffer from contrast loss due to the backlight’s bleed-through in the “off” pixels. OLEDs, being emissive, have a consistent contrast ratio with no limitation in viewing angle. In addition, they don’t suffer from temperature-related response time delays and contrast changes. Like any OLED display, the MI9639BO-W is made from a thin film of an organic compound that emits bright light when exposed to a current with a wide viewing angle and low power consumption, representing an ideal solution for displaying text or icons.

OLED W Click allows using both I2C and SPI interfaces. The selection can be made by positioning SMD jumpers labeled SEL COMM in an appropriate position. Note that all the jumpers’ positions must be on the same side, or the Click board™ may become unresponsive. In addition, it uses two more pins. The first is related to the reset function, routed to the RST pin on the mikroBUS™ socket. When this pin is in a low logic state, the initialization of the SSD1306 is executed. The second pin is labeled as D/C and routed to the PWM pin on the mikroBUS™ socket representing the I2C slave address selection pin in a case of selected I2C communication.

NOTE: If the noise accidentally occurs at the displaying window during the operation, please reset the display to recover the display function.

In addition to the display’s main power supply, taken from the +3.3V microBUS™ power rail, the MI9639BO-W has another power pin, more precisely, the power supply for its DC/DC converter circuit. This pin represents the power supply pin for the internal buffer of the DC/DC voltage converter, which is why this Click board™ uses a low dropout linear regulator AP7331 from Diodes Incorporated, providing a 3.6V power supply out of 5V mikroBUS™ rail.

This Click board™ is designed to be operated only with a 3.3V logic voltage level, while 5V is used as a supply voltage of the LDO. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

Specifications

Pinout diagram

This table shows how the pinout on OLED W Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	D/C	I2C Slave Address Selection
Reset	RST	2	RST	INT	15	NC
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
SPI Data IN	SDI	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

OLED W Click electrical specifications

Software Support

We provide a library for the OLED W Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for OLED W Click driver.

Key functions

• oledw_send This function sends commands or data to OLED W click.

• oledw_display_picture This function allows user to display picture for page addressing mode.

• oledw_set_contrast This function sets the display contrast level (0 to 255).

Example Description

This example demonstrates the use (control) of the OLED W display.

 void application_task ( void ) { 
     uint8_t i; 

     oledw_display_picture( &oledw, oledw_img ); 
     Delay_ms( 500 ); 
     oledw_send( &oledw, OLEDW_INVERTDISPLAY, OLEDW_COMMAND ); 
     Delay_ms( 500 ); 
     oledw_send( &oledw, OLEDW_NORMALDISPLAY, OLEDW_COMMAND ); 
     Delay_ms( 500 ); 
     oledw_send( &oledw, OLEDW_INVERTDISPLAY, OLEDW_COMMAND ); 
     Delay_ms( 500 ); 
     oledw_send( &oledw, OLEDW_NORMALDISPLAY, OLEDW_COMMAND ); 
     Delay_ms( 300 ); 

     for (i = 0xAF; i > 0x00; i--) { 
         oledw_set_contrast( &oledw, i ); 
         Delay_ms( 5 ); 
     } 

     for (i = 0x00; i < 0xAF; i++) { 
         oledw_set_contrast( &oledw, i ); 
         Delay_ms( 5 ); 
     } 

     oledw_scroll_right( &oledw, 0x00, 0x05 ); 
     Delay_ms( 1000 ); 
     oledw_stop_scroll( &oledw ); 
     oledw_display_picture( &oledw, oledw_img ); 

     oledw_scroll_left( &oledw, 0x00, 0x05 ); 
     Delay_ms( 1000 ); 
     oledw_stop_scroll( &oledw ); 
     oledw_display_picture( &oledw, oledw_img ); 

     oledw_scroll_diag_right( &oledw, 0x00, 0x05 ); 
     Delay_ms( 1000 ); 
     oledw_stop_scroll( &oledw ); 
     oledw_display_picture( &oledw, oledw_img ); 

     oledw_scroll_diag_left( &oledw, 0x00, 0x05 ); 
     Delay_ms( 1000 ); 
     oledw_stop_scroll( &oledw ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.OLEDW

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.