diff --git a/lib/sdk11/components/libraries/bootloader_dfu/bootloader.c b/lib/sdk11/components/libraries/bootloader_dfu/bootloader.c
index e145409..6fb0c0d 100644
--- a/lib/sdk11/components/libraries/bootloader_dfu/bootloader.c
+++ b/lib/sdk11/components/libraries/bootloader_dfu/bootloader.c
@@ -141,10 +141,7 @@ static void wait_for_events(void)
         }
 
         // Forced startup dfu mode timeout without any received packet
-        if (_terminate_startup_dfu)
-        {
-          return;
-        }
+        if (_terminate_startup_dfu) return;
     }
 }
 
diff --git a/src/Makefile b/src/Makefile
index 15cd311..9382e25 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -43,6 +43,13 @@ MK_DIS_FIRMWARE = "$(SD_NAME) $(SD_VERSION_FULL)"
 #******************************************************************************
 NRFUTIL = nrfutil
 
+
+ifneq ($(JLINK),)
+NRFJPROG = nrfjprog -s $(JLINK)
+else
+NRFJPROG = nrfjprog 
+endif
+
 ifeq ($(OS),Windows_NT)
 PROGFILES = C:/Program Files (x86)
 GNU_INSTALL_ROOT = $(PROGFILES)/GNU Tools ARM Embedded/6 2017-q2-update
@@ -355,11 +362,11 @@ all: $(BUILD)/$(OUTPUT_FILENAME).out size
 
 flash: $(BUILD)/$(OUTPUT_FILENAME).hex
 	@echo Flashing: $<
-	nrfjprog --program $< --sectoranduicrerase -f nrf52 --reset
+	$(NRFJPROG) --program $< --sectoranduicrerase -f nrf52 --reset
 	
 sd:
 	@echo Flashing: $(SD_HEX)
-	nrfjprog --program $(SD_HEX) -f nrf52 --chiperase  --reset	
+	$(NRFJPROG) --program $(SD_HEX) -f nrf52 --chiperase  --reset	
 
 
 ## Create build directories
diff --git a/src/main.c b/src/main.c
index 6c9e5e1..d302f4f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -40,7 +40,6 @@
 #include "bootloader.h"
 #include "bootloader_util.h"
 
-
 #include "nrf.h"
 #include "nrf_soc.h"
 #include "nrf_nvic.h"
@@ -64,14 +63,9 @@
 #include "tusb.h"
 #include "usb/msc_uf2.h"
 
-
 void usb_init(void);
 void usb_teardown(void);
 
-/* tinyusb function that handles power event (detected, ready, removed)
- * We must call it within SD's SOC event handler, or set it as power event handler if SD is not enabled. */
-extern void tusb_hal_nrf_power_event(uint32_t event);
-
 #else
 
 #define usb_init()
@@ -251,16 +245,16 @@ static uint32_t ble_stack_init(bool init_softdevice)
   // Enable Softdevice
   nrf_clock_lf_cfg_t clock_cfg =
   {
-#if 0
-      .source       = NRF_CLOCK_LF_SRC_RC,
-      .rc_ctiv      = 16,
-      .rc_temp_ctiv = 2,
-      .accuracy     = NRF_CLOCK_LF_ACCURACY_20_PPM
-#else
+#ifdef NRF52840_XXAA // TODO use xtal source for feather52832
       .source       = NRF_CLOCK_LF_SRC_XTAL,
       .rc_ctiv      = 0,
       .rc_temp_ctiv = 0,
       .accuracy     = NRF_CLOCK_LF_ACCURACY_20_PPM
+#else
+      .source       = NRF_CLOCK_LF_SRC_RC,
+      .rc_ctiv      = 16,
+      .rc_temp_ctiv = 2,
+      .accuracy     = NRF_CLOCK_LF_ACCURACY_20_PPM
 #endif
   };
 
@@ -367,16 +361,22 @@ int main(void)
     // Initiate an update of the firmware.
     APP_ERROR_CHECK( bootloader_dfu_start(_ota_update, 0) );
   }
+#ifdef NRF52832_XXAA
+  else
+  {
+    /* Adafruit Modification
+     * Even DFU is not active, we still force an 1000 ms dfu serial mode when startup
+     * to support auto programming from Arduino IDE */
+    (void) bootloader_dfu_start(false, BOOTLOADER_STARTUP_DFU_INTERVAL);
+  }
+#endif
 
   /*------------- Adafruit Factory reset -------------*/
   bool is_freset = ( !button_pressed(BOOTLOADER_BUTTON) && button_pressed(FRESET_BUTTON) );
 
-  if (is_freset)
-  {
-    adafruit_factory_reset();
-  }
+  if (is_freset) adafruit_factory_reset();
 
-  /*------------- Stop timer and jump to application -------------*/
+  /*------------- Hardware reset and jump to application -------------*/
   app_timer_stop(blinky_timer_id);
 
   led_off(LED_BLUE);
@@ -521,6 +521,7 @@ uint32_t proc_soc(void)
     pstorage_sys_event_handler(soc_evt);
 
 #ifdef NRF52840_XXAA
+    extern void tusb_hal_nrf_power_event(uint32_t event);
     /*------------- usb power event handler -------------*/
     int32_t usbevt = (soc_evt == NRF_EVT_POWER_USB_DETECTED   ) ? NRFX_POWER_USB_EVT_DETECTED:
                      (soc_evt == NRF_EVT_POWER_USB_POWER_READY) ? NRFX_POWER_USB_EVT_READY   :