diff --git a/atusb/fw/atusb.c b/atusb/fw/atusb.c
index 6264d7c..f526844 100644
--- a/atusb/fw/atusb.c
+++ b/atusb/fw/atusb.c
@@ -28,6 +28,7 @@
 int main(void)
 {
 	board_init();
+	board_app_init();
 	reset_rf();
 
 	user_get_descriptor = sernum_get_descr;
diff --git a/atusb/fw/board.h b/atusb/fw/board.h
index 1188a6b..90fb584 100644
--- a/atusb/fw/board.h
+++ b/atusb/fw/board.h
@@ -83,5 +83,6 @@ void timer_init(void);
 int gpio(uint8_t port, uint8_t data, uint8_t dir, uint8_t mask, uint8_t *res);
 
 void board_init(void);
+void board_app_init(void);
 
 #endif /* !BOARD_H */
diff --git a/atusb/fw/board_app.c b/atusb/fw/board_app.c
index ba1dd67..67e6353 100644
--- a/atusb/fw/board_app.c
+++ b/atusb/fw/board_app.c
@@ -11,6 +11,7 @@
  */
 
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include <avr/io.h>
@@ -19,6 +20,8 @@
 #define F_CPU   8000000UL
 #include <util/delay.h>
 
+#include "usb.h"
+#include "at86rf230.h"
 #include "board.h"
 #include "spi.h"
 
@@ -131,3 +134,25 @@ int gpio(uint8_t port, uint8_t data, uint8_t dir, uint8_t mask, uint8_t *res)
 
 	return 1;
 }
+
+
+ISR(INT0_vect)
+{
+	static uint8_t irq;
+
+	if (eps[1].state != EP_IDLE)
+		return;
+	spi_begin();
+	spi_send(AT86RF230_REG_READ | REG_IRQ_STATUS);
+	irq = spi_recv();
+	spi_end();
+	usb_send(&eps[1], &irq, 1, NULL, NULL);
+}
+
+
+void board_app_init(void)
+{
+	/* enable INT0, trigger on rising edge */
+	EICRA = 1 << ISC01 | 1 << ISC00;
+	EIMSK = 1;
+}
diff --git a/atusb/fw/descr.c b/atusb/fw/descr.c
index d32d455..147e180 100644
--- a/atusb/fw/descr.c
+++ b/atusb/fw/descr.c
@@ -56,7 +56,7 @@ const uint8_t config_descriptor[] = {
 #if 0
 	LE(9+9+7+7),		/* wTotalLength */
 #else
-	LE(9+9+9),		/* wTotalLength */
+	LE(9+9+7+9),		/* wTotalLength */
 #endif
 	2,			/* bNumInterfaces */
 	1,			/* bConfigurationValue (> 0 !) */
@@ -70,11 +70,7 @@ const uint8_t config_descriptor[] = {
 	USB_DT_INTERFACE,	/* bDescriptorType */
 	0,			/* bInterfaceNumber */
 	0,			/* bAlternateSetting */
-#if 0
-	2,			/* bNumEndpoints */
-#else
-	0,
-#endif
+	1,			/* bNumEndpoints */
 	USB_CLASS_VENDOR_SPEC,	/* bInterfaceClass */
 	0,			/* bInterfaceSubClass */
 	0,			/* bInterfaceProtocol */
@@ -89,7 +85,9 @@ const uint8_t config_descriptor[] = {
 	0x02,			/* bmAttributes (bulk) */
 	LE(EP1_SIZE),		/* wMaxPacketSize */
 	0,			/* bInterval */
+#endif
 
+#if 1
 	/* EP IN */
 
 	7,			/* bLength */