diff --git a/application.c b/application.c
index fab11db..e06fdbd 100644
--- a/application.c
+++ b/application.c
@@ -260,6 +260,8 @@ static void command_target_reset(void* argument)
 		} else if (0 == strcmp("PPH", argument)) { // set reset to push-pull active high
 			active_low = false; // remember we are active high
 			gpio_set_output_options(GPIO_PORT(TARGET_RST), GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, GPIO_PIN(TARGET_RST)); // set output as push-pull
+		} else {
+			printf("unknown argument: %s\n", argument);
 		}
 	}
 
@@ -857,6 +859,7 @@ void main(void)
 #endif
 
 	board_setup(); // setup board
+	exti_set_trigger(GPIO_EXTI(BUTTON_PIN), EXTI_TRIGGER_BOTH); // trigger when button is pressed or released
 	usb_cdcacm_setup(); // setup USB CDC ACM (for printing)
 	puts("\nwelcome to the CuVoodoo SWJ finder\n"); // print welcome message
 
@@ -1009,9 +1012,13 @@ void main(void)
 		}
 		if (button_flag) { // user pressed button
 			action = true; // action has been performed
-			puts("button pressed\n");
+			sleep_ms(50); // wait a bit to remove noise and double trigger
+			if (gpio_get(GPIO_PORT(BUTTON_PIN), GPIO_PIN(BUTTON_PIN))) { // button released
+				command_target_reset("0"); // release reset
+			} else {
+				command_target_reset("1"); // assert reset
+			}
 			led_toggle(); // toggle LED
-			sleep_ms(100); // wait a bit to remove noise and double trigger
 			button_flag = false; // reset flag
 		}
 		if (wakeup_flag) { // time to do periodic checks