<![CDATA[How to scale a bitmap drawn with M5.Display.drawBitmap() on M5Stack?]]>I am working with an M5Stack Core S3 using the <M5Unified.h> library. I successfully display a 32×32 bitmap stored as a uint16_t array (RGB565 format) using M5.Display.drawBitmap() (see my code below). The bitmap represents a small animal, but at its native resolution it appears too small on the display (see the result below). At the moment, M5.Display.drawBitmap() draws the image at a 1:1 pixel ratio, and I don’t see an obvious way to apply scaling. How to scale the image by an integer factor (for example, 2 or 3) so that it appears larger on the display?

My result:
20251221_122614.jpg

My main.cpp code:

#include <M5Unified.h>

constexpr int IMG_W = 32;
constexpr int IMG_H = 32;

const uint16_t myBitmap[IMG_W * IMG_H] = {
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xffff, 0x0823, 0x0000, 0x0000, 0x0000, 0x0823, 0xffff, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xffff, 0xffff, 0x0823, 0x0823, 0x0823, 0xffff, 0xffff, 0x0823, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xff39, 0x0823, 0x0823, 0xff39, 0xff39, 0xff39, 0x0823, 0x0823, 0xff39, 0xff39, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xff39, 0xf653, 0x0823, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0x0823, 0xff39, 0xf653, 0xff39, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xff39, 0x0823, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0x0823, 0xff39, 0xff39, 0xf653, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xff39, 0x0823, 0xff39, 0x0823, 0xff39, 0xff39, 0x0823, 0xff39, 0xff39, 0x0823, 0xff39, 0xf653, 0x0823, 0x0823, 0x0823, 0x0823, 0x0823, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0x0823, 0xff39, 0x0823, 0xff39, 0xff39, 0x0823, 0xff39, 0xff39, 0xf653, 0x0823, 0x0823, 0x0823, 0xf653, 0xff39, 0xff39, 0xff39, 0xff39, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0xf653, 0xf653, 0xf653, 0xf653, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xfd35, 0xfd35, 0xfd35, 0xfd35, 0xff39, 0xff39, 0xff39, 0xf653, 0xf653, 0xf653, 0xf653, 0xf653, 0xf653, 0xff39, 0xff39, 0xff39, 0xff39, 0xff39, 0x0823, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xf410, 0xfd35, 0xf410, 0xfd35, 0xfd35, 0xf653, 0xf653, 0xf653, 0x0823, 0xf653, 0xf653, 0xf653, 0xf653, 0xf653, 0xf653, 0xff39, 0xff39, 0xf653, 0x0823, 0xf653, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xfd35, 0xfd35, 0xfd35, 0xfd35, 0xfd35, 0xf653, 0x0823, 0x0823, 0xe4ed, 0xf653, 0xf653, 0xff39, 0xff39, 0xf653, 0xf653, 0xf653, 0xf653, 0xf653, 0x0823, 0xe4ed, 0xf653, 0x0823, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0x0823, 0x0823, 0x0823, 0x0823, 0x0823, 0xe4ed, 0xe4ed, 0xf653, 0xf653, 0xff39, 0xff39, 0xff39, 0xff39, 0xf653, 0xf653, 0xf653, 0xe4ed, 0x0823, 0x0823, 0xe4ed, 0x0823, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xf653, 0xf653, 0xf653, 0xf653, 0xff39, 0xff39, 0xff39, 0xe4ed, 0xf653, 0xe4ed, 0xe4ed, 0x0823, 0x0000, 0x0823, 0x0823, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0xe4ed, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xf653, 0xe4ed, 0x0823, 0x0823, 0x0823, 0xe4ed, 0xe4ed, 0xe4ed, 0x0823, 0x0823, 0x0823, 0x0823, 0xe4ed, 0xe4ed, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xf653, 0xe4ed, 0x0823, 0x0000, 0x0823, 0xe4ed, 0xe4ed, 0x0823, 0x0000, 0x0000, 0x0000, 0x0823, 0xe4ed, 0xe4ed, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0xf653, 0xe4ed, 0x0823, 0x0000, 0x0823, 0xe4ed, 0xe4ed, 0x0823, 0x0000, 0x0000, 0x0000, 0x0823, 0xe4ed, 0xe4ed, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0x0823, 0x0000, 0x0000, 0x0000, 0x0823, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0823, 0x0823, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,  
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 
};

void setup() {

  auto cfg = M5.config();

  M5.begin(cfg);

  M5.Display.clear(TFT_BLACK);

  M5.Display.drawBitmap(50,50,IMG_W,IMG_H,myBitmap);
 
}

void loop() {

}

My development enviroment:

  • Windows 10 Pro 22H2
  • Visual Studio Code 1.99.1 with PlatformIO 3.3.4
  • M5Stack Core S3
]]>https://community.m5stack.com/topic/7958/how-to-scale-a-bitmap-drawn-with-m5-display-drawbitmap-on-m5stackRSS for NodeWed, 29 Apr 2026 14:12:44 GMTSun, 21 Dec 2025 11:29:39 GMT60