diff --git a/midi2cv/drivers/gpio.cc b/midi2cv/drivers/gpio.cc
index 6185578..191df01 100644
--- a/midi2cv/drivers/gpio.cc
+++ b/midi2cv/drivers/gpio.cc
@@ -1,11 +1,10 @@
 #include "gpio.h"
 
-#include <gpio.h>
+#include <stm32f37x_conf.h>
+
 
 void GPIO::Init() {
-  gpio_mode_setup(0, 0, 0, 0);
 }
 
-
-void GPIO::Write() {
+void GPIO::Write(GPIO_TypeDef* port, uint16_t pin, bool state) {
 }
diff --git a/midi2cv/drivers/gpio.h b/midi2cv/drivers/gpio.h
index c3be452..a890880 100644
--- a/midi2cv/drivers/gpio.h
+++ b/midi2cv/drivers/gpio.h
@@ -3,6 +3,37 @@
 
 
 #include "stmlib/stmlib.h"
+#include <stm32f37x_conf.h>
+
+#define PORT_RST_OLED GPIOB
+#define PIN_RST_OLED GPIO_Pin_0
+#define PORT_SS_DAC0 GPIOB
+#define PIN_SS_DAC0 GPIO_Pin_6
+#define PORT_SS_DAC1 GPIOB
+#define PIN_SS_DAC1 GPIO_Pin_7
+#define PORT_RST_USB GPIOB
+#define PIN_RST_USB GPIO_Pin_8
+#define PORT_SS_USB GPIOB
+#define PIN_SS_USB GPIO_Pin_9
+#define PORT_SS_OLED GPIOB
+#define PIN_SS_OLED GPIO_Pin_11
+#define PORT_SDC_OLED GPIOB
+#define PIN_SDC_OLED GPIO_Pin_12
+
+#define PORT_GATE_OUT_1 GPIOA
+#define PIN_GATE_OUT_1 GPIO_Pin_0
+#define PORT_GATE_OUT_2 GPIOA
+#define PIN_GATE_OUT_2 GPIO_Pin_1
+#define PORT_GATE_OUT_3 GPIOA
+#define PIN_GATE_OUT_3 GPIO_Pin_2
+#define PORT_GATE_OUT_4 GPIOA
+#define PIN_GATE_OUT_4 GPIO_Pin_3
+#define PORT_GATE_OUT_5 GPIOA
+#define PIN_GATE_OUT_5 GPIO_Pin_4
+#define PORT_GATE_OUT_6 GPIOA
+#define PIN_GATE_OUT_6 GPIO_Pin_5
+
+#define GPIO_PIN(x) PORT_##x, PIN_##x
 
 class GPIO {
   public:
@@ -10,7 +41,7 @@ class GPIO {
     ~GPIO() {}
 
     void Init();
-    void Write();
+    void Write(GPIO_TypeDef* port, uint16_t pin, bool state);
   private:
     DISALLOW_COPY_AND_ASSIGN(GPIO);
 };
diff --git a/stmlib b/stmlib
index 035540a..3394699 160000
--- a/stmlib
+++ b/stmlib
@@ -1 +1 @@
-Subproject commit 035540af5f0877c3246d28bd952bf2316e65788b
+Subproject commit 3394699e1046c5eef6269db87e965c788a9ebe25