Interfacing OLED SSD1306 with nRF52832 on Zephyr

[Amank0623]

Subject: Query: Interfacing OLED SSD1306 with nRF52832 on Zephyr

Dear Zephyr Dev Zone Community,

I hope this message finds you well. I am currently working on a project that involves interfacing an OLED SSD1306 display with an nRF52832 microcontroller using the Zephyr RTOS. I have encountered some challenges during the integration process and would greatly appreciate your assistance in resolving them.

Specifically, I am facing issues with initializing and communicating with the OLED SSD1306 display through the nRF52832 microcontroller. Despite following the documentation and examples available, I have been unable to achieve successful communication and display output.

Here are some key details about my setup and the issues I'm encountering:

1. Hardware Setup:

   • OLED SSD1306 display (specify model/version if applicable)
   • nRF52832 microcontroller development board
   • Connections made using (I2C/SPI) interface
   • Power supply and wiring configurations

2. Software Environment:

   • Zephyr RTOS version: [Specify version]
   • Development environment/tools used: [Specify IDE, SDK, etc.]
   • Relevant code snippets/configuration files: [Provide snippets of initialization code, device tree configuration, etc.]

3. Issues Encountered:

   • Initialization problems: Difficulty initializing the OLED display driver.
   • Communication errors: Unable to establish communication between the microcontroller and the OLED display.
   • Display output: No output or incorrect display output observed on the OLED screen.

I would greatly appreciate any guidance, tips, or insights you can provide to help me overcome these challenges and successfully interface the OLED SSD1306 display with the nRF52832 microcontroller on the Zephyr RTOS.

Thank you very much for your time and assistance. I look forward to your valuable input and suggestions.

Best regards, Aman

[Øyvind]

Hello, 

What version of the nRF Connect SDK are you using? 

Here are some key details about my setup and the issues I'm encountering:

The information provided does not include what version you are using. 

, I am facing issues with initializing and communicating with the OLED SSD1306 display through the nRF52832 microcontroller.

How are you building the project for the nRF52832 and OLED display? Is this custom HW or are you using our nRF52832 Development Kit? How are you connecting the device? Have you ensured that you are using the correct GPIO? 

As mentioned in  Inquiry about Interfacing Grove LCD (White Blue) with NRF52832 did you test with the Zephyr Display driver sample?

Kind regards,
Øyvind

[Amank0623]

i am using sdk version 2.4.2 and displaying data as well but problem is that data is just coming in the half of the size of  text/char that i have written to be printed

[Øyvind]

Have you seen our blog post Printing to an I2C OLED display using nRF Connect SDK? Here it states, for the overlay file:

For nRF52832: Use compatible = "nordic,nrf-twi"; instead of compatible = "nordic,nrf-twim"; also remove the line zephyr,concat-buf-size = <4096>;

[Amank0623]

yes, i have already change all the things

[Øyvind]

Please provide more details on your setup, i.e. how you have connected, the overlay files etc. And please provide an image or similar to the fault. This way I can try to reproduce on my side.

[Amank0623]

/*overlay file*/

&arduino_i2c {                                                                                
    status = "okay";  
    compatible = "nordic,nrf-twi";                                                                  
  //  zephyr,concat-buf-size = <2048>;                                                      
                                                                                         
    ssd1306fb: ssd1306fb@3c {                                                                          
            compatible = "solomon,ssd1306fb";                                            
            reg = <0x3c>;                                                                
            label = "SSD1306";                                                            
            width = <128>;                                                                
            height = <64>;                                                                
            segment-offset = <0>;                                                        
            page-offset = <0>;                                                            
            display-offset = <0>;                                                        
            multiplex-ratio = <63>;                                                      
            segment-remap;                                                                
            com-invdir;
            inversion-on;                                                                  
            prechargep = <0x22>;                                                          
    };                                                                                    
};

[Amank0623]

/*prj*/

CONFIG_GPIO=y

CONFIG_HEAP_MEM_POOL_SIZE=16384
CONFIG_MAIN_STACK_SIZE=4096

CONFIG_DEBUG_OPTIMIZATIONS=y
CONFIG_ASSERT=y

CONFIG_I2C=y

CONFIG_DISPLAY=y
CONFIG_DISPLAY_LOG_LEVEL_DBG=y
# CONFIG_LOG_STRDUP_BUF_COUNT=

CONFIG_SSD1306=y
CONFIG_SSD1306_REVERSE_MODE=y
# CONFIG_SSD1306_SH1106_COMPATIBLE=n

CONFIG_LOG=y

# Console
CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y
CONFIG_STDOUT_CONSOLE=y
CONFIG_PRINTK=y
CONFIG_EARLY_CONSOLE=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_RTT_CONSOLE=y

# CFB
CONFIG_CFB_LOG_LEVEL_DBG=y
CONFIG_CHARACTER_FRAMEBUFFER=y

[Amank0623]

/*main*/

#include <zephyr/zephyr.h>
#include <zephyr/device.h>
#include <zephyr/drivers/display.h>
#include <zephyr/display/cfb.h>
#include <stdio.h>
#define FRAMEBUFFER_SIZE_MULTIPLIER 2

void main()
{
const struct device *dev;
uint8_t font_width;
uint8_t font_height;
uint16_t display_width;
uint16_t display_height;
// struct char_framebuffer *fb = &char_fb;

dev = device_get_binding("SSD1306");

if (dev == NULL)
{
printk("Device not found\n");
return;
}

if (display_set_pixel_format(dev, PIXEL_FORMAT_MONO10) != 0)
{
printk("Failed to set required pixel format\n");
return;
}

printk("initialized %s\n", "SSD1306");

if (cfb_framebuffer_init(dev))
{
printk("Framebuffer initialization failed!\n");
return;
}

// fb->size = fb->x_res * fb->y_res / fb->ppt * FRAMEBUFFER_SIZE_MULTIPLIER;

int err = (cfb_framebuffer_clear(dev, true));
// printk("%d\n", err);
cfb_framebuffer_invert(dev);
display_blanking_off(dev);

if (cfb_get_font_size(dev, 0, &font_width, &font_height))
{
printk("Failed to get font size\n");
return;
}

display_width = cfb_get_display_parameter(dev, CFB_DISPLAY_WIDTH);
display_height = cfb_get_display_parameter(dev, CFB_DISPLAY_HEIGH);

const char *text = "Hello, World!";
const uint16_t text_width = font_width;
const uint16_t text_height = font_height;

// Adjust starting position to display text at the bottom
const uint16_t *start_x = (display_width - text_width)/2;
const uint16_t *start_y = display_height - text_height/2;

printk("start_x=%d\n", start_x);
printk("start_y=%d\n", start_y);

if (cfb_draw_text(dev, text, start_x, start_y))
 {
printk("Failed to print string\n");
return;
}

// cfb_invert_area(dev,0, 22,text_width,text_height);
 cfb_framebuffer_finalize(dev); // display_blanking_on(dev);
}