Bitmap image scale doubling vertically on Oled SSD1306 display

[rossage99]

Hi there,

Currently undertaking a project in which i'm looking to display a QR code via an Oled display. I'm looking to achieve this through converting a png of a generated qr code and then converting it into bitmap code. I have had success getting the image onto the screen and while the image has scaled correctly horizontally, vertically it's stretching to twice the length it should be and is only displaying the upper half of the image (see attached image named screen distort)

I've tried playing around with all of the settings in the Image2CPP tool and while I can adjust the canvas size to fit the whole image onto the screen, it's half the size i want and still distorted vertically, or I can adjust the image to scale properly to half the screen size but it displays two qr codes side by side instead of one. I have also tried changing the screen address from 0x3c to 0x3d in case i was using the wrong one but no luck there.

here is the code im using;

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

const unsigned char myBitmap [] PROGMEM = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x77, 0x61, 0x98, 0x3e, 0x00, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x36, 0x61, 0x98, 0x1c, 0x00, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xff, 0x38, 0x01, 0xe1, 0xec, 0xff, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xff, 0x38, 0x01, 0xe1, 0xec, 0xff, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x30, 0x7f, 0xe7, 0x9c, 0xc0, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x30, 0x7f, 0xe7, 0xbc, 0xc0, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x30, 0x66, 0x78, 0x7c, 0xc0, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x30, 0x66, 0x78, 0x7c, 0xc0, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x37, 0x86, 0x18, 0x04, 0xc0, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x37, 0x86, 0x18, 0x04, 0xc0, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xff, 0x3e, 0x19, 0xe7, 0x84, 0xff, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xfe, 0x3e, 0x19, 0xe7, 0x84, 0x7f, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x36, 0x66, 0x66, 0x64, 0x00, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x76, 0x66, 0x46, 0xe6, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x67, 0x81, 0xe7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x23, 0x81, 0xe7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x0f, 0x36, 0x01, 0x81, 0xf3, 0xc0, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x1f, 0xf6, 0x20, 0x07, 0xb0, 0xc1, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x3f, 0xf6, 0x60, 0x07, 0x90, 0xc3, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0xf0, 0x70, 0x00, 0xc3, 0xf0, 0x30, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0xf0, 0x30, 0x01, 0xe1, 0xf0, 0x30, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf8, 0x0f, 0xf8, 0x3f, 0xff, 0xe7, 0xff, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x0f, 0xf8, 0x7f, 0xff, 0xe7, 0xff, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x03, 0x00, 0x66, 0x78, 0xf3, 0xb3, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0x03, 0x00, 0x66, 0x78, 0x73, 0x33, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0xf3, 0x8f, 0x86, 0x60, 0x30, 0x30, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0xf3, 0xcf, 0x86, 0x60, 0x10, 0x30, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xcf, 0x06, 0x19, 0xe7, 0x84, 0xf3, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xcf, 0x02, 0x19, 0xe7, 0x84, 0xf3, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xcc, 0xc1, 0x9e, 0x07, 0x90, 0xcf, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xcc, 0xc1, 0x9e, 0x07, 0x90, 0xcf, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x3c, 0x37, 0xe6, 0x18, 0x07, 0x0f, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x3c, 0x77, 0xe6, 0x18, 0x07, 0x8f, 0x0f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x0f, 0xfe, 0x7e, 0x79, 0x83, 0xf3, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x0f, 0xfe, 0x7e, 0x79, 0x83, 0xf3, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xf0, 0x0e, 0x78, 0x00, 0x73, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfb, 0xe0, 0x0e, 0x38, 0x00, 0x73, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x03, 0xc6, 0x18, 0x18, 0x63, 0xc0, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0x03, 0xc2, 0x18, 0x38, 0x61, 0xc0, 0x7f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xfc, 0xfc, 0x31, 0xf8, 0x7e, 0x60, 0x0f, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xfc, 0x71, 0xfc, 0xf8, 0xe0, 0x07, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf1, 0xff, 0xf9, 0xe7, 0xc3, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x79, 0xff, 0xe7, 0x86, 0xc7, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x39, 0xfe, 0x67, 0x84, 0xcf, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xfe, 0x3e, 0x00, 0x67, 0x87, 0xcf, 0xdf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xff, 0x3e, 0x00, 0x67, 0x87, 0xcf, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x3e, 0x0f, 0xe0, 0x40, 0x0c, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x3e, 0x1f, 0xe0, 0x60, 0x0c, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x37, 0x99, 0x98, 0x67, 0x0c, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x37, 0x99, 0x98, 0x67, 0x0c, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x30, 0x66, 0x60, 0x13, 0xff, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0x03, 0x30, 0x66, 0x60, 0x13, 0xff, 0xcf, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xff, 0x33, 0xe1, 0xfe, 0x63, 0xc3, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf3, 0xff, 0x33, 0xe1, 0xfe, 0x61, 0xc3, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x31, 0x9f, 0xe7, 0xe0, 0xcf, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x71, 0x9f, 0xe7, 0xe0, 0xcf, 0x3f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};

void setup() {

display.begin(SSD1306_SWITCHCAPVCC, 0x3c);
display.clearDisplay();
delay(2000);

}

void loop() {

display.drawBitmap(0,0,myBitmap, 128,64,WHITE);
display.display();

}

I have attached an image of the Image2Cpp settings i've used, if anyone can offer any help on this issue it would be greatly appreciated!

Thanks

[david_prentice]

It displays fine on my SSD1306 if you use a conventional constructor:

Adafruit_SSD1306 display(128, 64, &Wire);

I get a non-interleaved picture with your constructor like you.

Using the above constructor and building for a Uno:

Using library SPI at version 1.0 in folder: C:\Program Files (x86)\Arduino-1.8.13\hardware\arduino\avr\libraries\SPI 
Using library Wire at version 1.0 in folder: C:\Program Files (x86)\Arduino-1.8.13\hardware\arduino\avr\libraries\Wire 
Using library Adafruit_GFX_Library at version 1.10.7 in folder: C:\Users\David Prentice\Documents\Arduino\libraries\Adafruit_GFX_Library 
Using library Adafruit_SSD1306 at version 2.4.3 in folder: C:\Users\David Prentice\Documents\Arduino\libraries\Adafruit_SSD1306 
Using library Adafruit_BusIO at version 1.6.0 in folder: C:\Users\David Prentice\Documents\Arduino\libraries\Adafruit_BusIO 
"C:\\Users\\David Prentice\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-size" -A "C:\\Users\\DAVIDP~1\\AppData\\Local\\Temp\\arduino_build_599435/Adafruit_SSDxxxx.ino.elf"
Sketch uses 14094 bytes (43%) of program storage space. Maximum is 32256 bytes.
Global variables use 344 bytes (16%) of dynamic memory, leaving 1704 bytes for local variables. Maximum is 2048 bytes.

David.

p.s. there is not much point in using the OLED_RESET argument if there is no RST connection.
p.s. there is no point in making a 128x64 bitmap when you have a 64x64 QR code. (you can plot anywhere on the screen with foreground and background colours)

[rossage99]

Brilliant!

I thought it would be a relatively simple fix, I just wasn't sure where to make the adjustments.
Thanks very much David, much appreciated.

[david_prentice]

Your constructor should have worked with older versions i.e. default 128x64 128x32 and I2C
Adafruit are forever updating their libraries.

I have not studied the current library code.

David.

Edit. The answer is simple. The library defaults to:

#define SSD1306_128_32 ///< DEPRECATED: old way to specify 128x32 screen

Hence the short form constructor assumed a 128x32 screen.
Yes, I had forgotten. In the olden days you had to edit the H file for SSD1306_128_64

The current constructors are more flexible e.g. geometry.