diff --git a/src/main.cpp b/src/main.cpp
index 5f9eb23..cedb462 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -9,6 +9,22 @@ extern "C" {
 #include <myclass.h>
 #include <mare.h>
 
+void setPixel(uint8_t* img, uint16_t x, uint16_t y, bool value){
+    img += (sizeof(uint8_t)*x*(EPD_2IN9_V2_WIDTH>>3)+ sizeof(uint8_t)*(y>>3));
+    if (value) *img &= ~0x01 << (y%8);
+    else *img |= 0x01 << y%8; 
+}
+
+void drawSquare(uint8_t* img, uint16_t x, uint16_t y, uint16_t dimX, uint16_t dimY){
+    for (auto xx(0); xx< dimX; xx++){
+        for (auto yy(0); yy < dimY; yy++)
+        {
+            setPixel(img,x+xx,y+yy,true);
+        }
+        
+    }
+}
+
 int main(){
     stdio_init_all();
     const uint LED_PIN = PICO_DEFAULT_LED_PIN;
@@ -19,7 +35,7 @@ int main(){
     uint8_t img[EPD_2IN9_V2_HEIGHT/8*EPD_2IN9_V2_WIDTH];
 
     for (int x=0; x < EPD_2IN9_V2_HEIGHT/8*EPD_2IN9_V2_WIDTH; ++x){
-        img[x] = 0x01;
+        img[x] = 0xff;
     }
 
     int rv;
@@ -31,10 +47,29 @@ int main(){
     EPD_2IN9_V2_Init();
     EPD_2IN9_V2_Clear();
 
+    //clear delta memory
+    uint8_t delta[EPD_2IN9_V2_HEIGHT][EPD_2IN9_V2_WIDTH/8];
+    for(auto i(0); i < EPD_2IN9B_V3_HEIGHT; ++i){
+        for (auto j(0); j< EPD_2IN9B_V3_WIDTH/8; ++j){
+            delta[i][j]=0xff;
+        }
+    }
+    uint8_t dot(16);
+
     while(true){
-        EPD_2IN9_V2_Display((uint8_t*)img);
-        sleep_ms(10000);
-        EPD_2IN9_V2_Clear();
+        EPD_2IN9_V2_Display_Base((uint8_t*)img);
+        //EPD_2IN9_V2_Clear();
+        for (auto x(0); x <= EPD_2IN9_V2_HEIGHT-dot;x+=dot){
+            for(auto y(0); y <= EPD_2IN9_V2_WIDTH-dot;y+=dot){
+                drawSquare((uint8_t*)delta,x,y,dot,dot); 
+                EPD_2IN9_V2_Display_Partial((uint8_t*)delta);
+            }
+            for(auto i(0); i < EPD_2IN9B_V3_HEIGHT; ++i){
+                for (auto j(0); j< EPD_2IN9B_V3_WIDTH/8; ++j){
+                    delta[i][j]=0xff;
+                }
+            }
+        }
         printf("[%u] Hello, world!\n",i++);
         gpio_put(LED_PIN,s);
         s = s ? false : true;