diff --git a/firmware/common/hackrf_core.c b/firmware/common/hackrf_core.c
index d3329c6f..6212c974 100644
--- a/firmware/common/hackrf_core.c
+++ b/firmware/common/hackrf_core.c
@@ -853,6 +853,9 @@ void pin_setup(void) {
 	/* Safe state: start with VAA turned off: */
 	disable_rf_power();
 
+	scu_pinmux(SCU_PINMUX_GPIO3_10, SCU_GPIO_PDN | SCU_CONF_FUNCTION0);
+	scu_pinmux(SCU_PINMUX_GPIO3_11, SCU_GPIO_PDN | SCU_CONF_FUNCTION0);
+
 	gpio_input(&gpio_sync_in_a);
 	gpio_input(&gpio_sync_in_b);
 
@@ -904,9 +907,8 @@ void led_toggle(const led_t led) {
 	gpio_toggle(&gpio_led[led]);
 }
 
-void hw_sync_start() {
+void hw_sync_syn() {
 	gpio_set(&gpio_sync_out_a);
-	gpio_set(&gpio_sync_out_b);
 }
 
 void hw_sync_stop() {
@@ -914,6 +916,10 @@ void hw_sync_stop() {
 	gpio_clear(&gpio_sync_out_b);
 }
 
+void hw_sync_ack() {
+	gpio_set(&gpio_sync_out_b);
+}
+
 void hw_sync_copy_state() {
 	if(gpio_read(&gpio_sync_in_a)) {
 		gpio_set(&gpio_sync_out_a);
diff --git a/firmware/common/hackrf_core.h b/firmware/common/hackrf_core.h
index 4458a65d..78ccde41 100644
--- a/firmware/common/hackrf_core.h
+++ b/firmware/common/hackrf_core.h
@@ -271,8 +271,9 @@ void led_on(const led_t led);
 void led_off(const led_t led);
 void led_toggle(const led_t led);
 
-void hw_sync_start();
+void hw_sync_syn();
 void hw_sync_stop();
+void hw_sync_ack();
 bool hw_sync_ready();
 void hw_sync_copy_state();
 
diff --git a/firmware/hackrf_usb/hackrf_usb.c b/firmware/hackrf_usb/hackrf_usb.c
index adcdbcab..393a1cb8 100644
--- a/firmware/hackrf_usb/hackrf_usb.c
+++ b/firmware/hackrf_usb/hackrf_usb.c
@@ -253,26 +253,19 @@ int main(void) {
 
 	unsigned int phase = 0;
 
-	hw_sync_start();
+	led_off(LED3);
+	hw_sync_syn();
 	while(true) {
 		// Check whether we need to initiate a CPLD update
 		if (start_cpld_update)
 			cpld_update();
 
 
-		hw_sync_copy_state();
-
-		// check for hardware sync
 		if(hw_sync_ready()) {
 			synced = true;
-			//hw_sync_start();
-		} else if(hw_sync_count++ > 1000000) {
-			//hw_sync_stop();
-			led_toggle(LED3);
-			hw_sync_count = 0;
-		} else if(hw_sync_count == 500000) {
-			//hw_sync_start();
-		}
+			hw_sync_ack();
+			led_on(LED3);
+		} 
 
 		//int gpio_sync_in_flag = gpio_get(gpio_sync_in);