diff --git a/include/adc.h b/include/adc.h
new file mode 100644
index 0000000..56b5f45
--- /dev/null
+++ b/include/adc.h
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <inttypes.h>
+
+void ADC0_Init();
+int16_t ADC0_TR_DATA();
diff --git a/src/adc.c b/src/adc.c
new file mode 100644
index 0000000..16dbb8c
--- /dev/null
+++ b/src/adc.c
@@ -0,0 +1,25 @@
+#include "adc.h"
+#include "derivative.h"
+
+void ADC0_Init() {
+    // Enable ADC0 and PORTE clock
+    SIM->SCGC6 |= SIM_SCGC6_ADC0_MASK;
+    SIM->SCGC5 |= SIM_SCGC5_PORTE_MASK;
+
+    // USE AD0 (ADC0_SE4a)
+    PORTE->PCR[21] |= PORT_PCR_MUX(0x0);
+
+    ADC0->CFG1 = ADC_CFG1_ADLSMP_MASK      // Sample time 0 = Short, 1 = Long
+                 | ADC_CFG1_MODE(0x01);    // Conversion mode 00 = 8-bit, 01 = 12-bit, 10 = 10-bit, 11 = 16-bit
+    ADC0->SC3 = ADC_SC3_ADCO_MASK          // Continuous Conversion if AVGE = 1
+                | ADC_SC3_AVGE_MASK        // Hardware average
+                | ADC_SC3_AVGS(0x01);      // Hardware average 00 = 4 samples, 01 = 8, 10 = 16, 11 = 32
+    ADC0->SC1[0] = ADC_SC1_ADCH(0b00100);  // Input channel select, AD4a is selected as input
+}
+
+int16_t ADC0_TR_DATA() {
+    while (!(ADC0->SC1[0] & ADC_SC1_COCO_MASK)) asm("nop");
+    int16_t ADC_Result = ADC0->R[0];
+    ADC0->SC1[0] &= ~ADC_SC1_COCO_MASK;
+    return ADC_Result;
+}
diff --git a/src/tftlcd.c b/src/tftlcd.c
index bd592d8..cac27f8 100644
--- a/src/tftlcd.c
+++ b/src/tftlcd.c
@@ -2,9 +2,9 @@
 #include "systick.h"
 #include "tftlcd.h"
 
-uint16_t PEN_COLOR = 0x0000;   // 画笔颜色
-uint16_t BACK_COLOR = 0xFFFF;  // 背景颜色
-uint16_t DeviceCode;           // 设备模式
+uint16_t PEN_COLOR = BLACK;   // 画笔颜色
+uint16_t BACK_COLOR = WHITE;  // 背景颜色
+uint16_t DeviceCode;          // 设备模式
 
 void LCD_RESET() {
     LCD_RST_CLR;