diff --git a/firmware/include_board/owhw/board.h b/firmware/include_board/owhw/board.h
index fa1cac16..cd15339a 100644
--- a/firmware/include_board/owhw/board.h
+++ b/firmware/include_board/owhw/board.h
@@ -35,6 +35,8 @@
 #define PINS_USIM1		PINS_TC_USIM1, PINS_ISO7816_USIM1, PIN_USIM1_nRST, PIN_SET_USIM1_PRES
 #define PINS_USIM2		PINS_TC_USIM2, PINS_ISO7816_USIM2, PIN_USIM2_nRST, PIN_SET_USIM2_PRES
 
+#define PINS_CARDSIM		{ PIN_SET_USIM1_PRES, PIN_SET_USIM2_PRES }
+
 #define SIMTRACE_VENDOR_ID          0x1d50
 #define SIMTRACE_PRODUCT_ID         0x60e3	/* FIXME */
 #define USB_VENDOR_ID               SIMTRACE_VENDOR_ID
diff --git a/firmware/src_board/owhw.c b/firmware/src_board/owhw.c
new file mode 100644
index 00000000..c020d64d
--- /dev/null
+++ b/firmware/src_board/owhw.c
@@ -0,0 +1,39 @@
+/* Card simulator specific functions */
+/* (C) 2015 by Harald Welte <hwelte@hmw-consulting.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include "chip.h"
+#include "board.h"
+
+static const Pin pins_cardsim[] = PINS_CARDSIM;
+
+void cardsim_set_simpres(uint8_t slot, int present)
+{
+	if (slot > 1)
+		return;
+
+	if (present)
+		PIO_Set(&pins_cardsim[slot]);
+	else
+		PIO_Clear(&pins_cardsim[slot]);
+}
+
+void cardsim_gpio_init(void)
+{
+	PIO_Configure(&pins_cardsim, ARRAY_SIZE(pins_cardsim));
+}