diff --git a/main.c b/main.c
index e964d62..dcd45c8 100644
--- a/main.c
+++ b/main.c
@@ -1,3 +1,4 @@
+#include "adc.h"
 #include "derivative.h"
 #include "systick.h"
 #include "tftlcd.h"
@@ -5,20 +6,47 @@
 #include <stdio.h>
 #include <string.h>
 
+#define ADC_M 2048
+
 int main(void) {
     // Initialize
-    SysTick_Config(CORCLK / 1000);  // Period of systick timer : 1ms
-    uart_init(UART_MSG, 9600);      // Initialize UART1 with PC
-    uart_rie_enable(UART_MSG);      // Enable UART1 receive interrupt
-    LCD_Init();                     // Initialize LCD
+    uart_init(UART_MSG, 9600);  // Initialize UART1 with PC
+    uart_rie_enable(UART_MSG);  // Enable UART1 receive interrupt
+    LCD_Init();                 // Initialize LCD
+    adc0_Init();                // Initialize ADC0
 
     uart_printf(UART_MSG, "System Clock: %lu\r\n", CORCLK);
     uart_printf(UART_MSG, "Bus Clock: %lu\r\n", BUSCLK);
 
+    LCD_ShowString(LCD_W / 3, 0, "Audio Sample", 16, 0, 1);
+    LCD_DrawLine(0, 16, LCD_W - 1, 16);
+
+    uint16_t x0 = 16, y0 = 32;
+    uint16_t x1 = LCD_W - 8, y1 = LCD_H - 16;
+    uint16_t ym = (y0 + y1) / 2;
+    LCD_DrawLine(x0, y0, x0, y1);
+    LCD_DrawLine(x0, ym, x1, ym);
+    LCD_ShowChar(0, y0, 'A', 16, 0);
+    LCD_ShowChar(x1, ym, 'T', 16, 0);
+
+    LCD_SetColor(BACK_COLOR);
+
+    int16_t res;
+    uint16_t pos[x1 - x0 - 1];
+    uint16_t x = x0 + 1, y;
     uint32_t timer = 0;
+
     for (;;) {
-        if (timer_expired(&timer, 1000)) {
-            uart_printf(UART_MSG, "UART RD: %d, tick: %lu\r\n", UART_MSG->S1 & UART_S1_RDRF_MASK ? 1 : 0, ms_ticks);
+        if (timer_expired_10us(&timer, 5)) {
+            LCD_DrawPoint(x, pos[x - x0 - 1], BACK_COLOR);
+
+            res = adc0_TR_DATA() - 1550;
+            y = ym + res * (y1 - ym) / ADC_M;
+            LCD_DrawPoint(x, y, RED);
+            LCD_DrawPoint(x, ym, BLACK);
+
+            pos[x - x0 - 1] = y;
+            x = x + 1 < x1 ? x + 1 : x0 + 1;
         }
     }
 }