diff --git a/src/hardware.h b/src/hardware.h
new file mode 100644
index 0000000..a1ee216
--- /dev/null
+++ b/src/hardware.h
@@ -0,0 +1,33 @@
+#ifndef _HARDWARE_H
+#define _HARDWARE_H
+
+/* Touch sensors keypad
+ * PCB Layout: see ESP32 Datasheet A.2. PCB Layout
+ */
+#define TOUCH_PAD_NUM 10
+
+//Touch0 GPIO 4
+//Touch1 GPIO 0 /* don't use: pullup on dev board */
+//Touch2 GPIO 2 /* don't use: pullup on dev board */
+//Touch3 GPIO15
+//Touch4 GPIO13
+//Touch5 GPIO12
+//Touch6 GPIO14
+//Touch7 GPIO27
+//Touch8 GPIO33
+//Touch9 GPIO32
+
+#define LED_PIN 21
+
+/* SD card
+ */
+#define PIN_SD_CD 17
+#define PIN_SD_CS 5
+
+/* I2S
+ */
+#define I2S_NUM 0
+
+#define BUF_LENGTH 1024
+
+#endif /* _HARDWARE_H */
diff --git a/src/keyboard.h b/src/keyboard.h
index d6cdf69..4b13ce1 100644
--- a/src/keyboard.h
+++ b/src/keyboard.h
@@ -2,8 +2,8 @@
 #define _KEYBOARD_H
 
 #include "driver/touch_pad.h"
+#include "hardware.h"
 
-#define TOUCH_PAD_NUM 10
 
 static bool s_pad_activated[TOUCH_PAD_NUM];
 
diff --git a/src/main.cpp b/src/main.cpp
index b2be7b1..fe01ebd 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -7,14 +7,13 @@
  */
 #include "Arduino.h"
 
+#include "hardware.h"
 #include "keyboard.h"
 #include "sdcard.h"
 #include "sound.h"
 #include "ringbuf.h"
 
 #define VERSION "0.0"
-#define LED_PIN 21
-#define BUF_LENGTH 1024
 
 #define WIFI_SSID "ssid"
 #define WIFI_PASSWORD "password"
diff --git a/src/sdcard.cpp b/src/sdcard.cpp
index cc84e6e..8b2f6ea 100644
--- a/src/sdcard.cpp
+++ b/src/sdcard.cpp
@@ -10,13 +10,13 @@
 #include "SD.h"
 #include "SPI.h"
 
+#include "hardware.h"
 #include "sdcard.h"
 #include "sound.h"
 
 using namespace std;
 
 static const char* TAG = "SDCard";
-#define PIN_SD_CD 17
 
 SDCard::SDCard() {
 }
@@ -26,7 +26,7 @@ void SDCard::mount() {
     if (!digitalRead(PIN_SD_CD)) {
       Serial.println("No card detected!");
     }
-    if(!SD.begin(5)){
+    if(!SD.begin(PIN_SD_CS)){
         Serial.println("Card Mount Failed");
         return;
     }
diff --git a/src/sound.h b/src/sound.h
index 452f5a9..108f7ad 100644
--- a/src/sound.h
+++ b/src/sound.h
@@ -4,8 +4,7 @@
 #include "Arduino.h"
 
 #include "driver/i2s.h"
-
-#define I2S_NUM 0
+#include "hardware.h"
 
 
 typedef struct {