diff --git a/.gitignore b/.gitignore
index 8b6e4de0ae..04c7fff6f4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,7 +7,6 @@
 *.bin
 *.map
 *.hex
-!ports/nrf/**/bootloader/**/*.hex
 *.dis
 *.exe
 
diff --git a/.travis.yml b/.travis.yml
index 93d981518c..ecc94ba648 100755
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,7 +30,8 @@ env:
   - TRAVIS_BOARD=pirkey_m0
   - TRAVIS_BOARD=gemma_m0
   - TRAVIS_BOARD=hallowing_m0_express
-  - TRAVIS_BOARD=feather52832
+  - TRAVIS_BOARD=feather_nrf52832
+  - TRAVIS_BOARD=feather_nrf52840_express
 
 addons:
   artifacts:
@@ -54,7 +55,7 @@ before_script:
   - ([[ -z "$TRAVIS_BOARD" || $TRAVIS_BOARD = "feather_huzzah" ]] || (wget https://s3.amazonaws.com/adafruit-circuit-python/gcc-arm-embedded_7-2018q2-1~trusty1_amd64.deb && sudo dpkg -i gcc-arm-embedded*_amd64.deb))
 
   # For nrf builds
-  - ([[ $TRAVIS_BOARD != "feather52832" && $TRAVIS_BOARD != "pca10056" ]] || sudo ports/nrf/drivers/bluetooth/download_ble_stack.sh)
+  - ([[ $TRAVIS_BOARD != "feather_nrf52832" && $TRAVIS_BOARD != "feather_nrf52840_express" && $TRAVIS_BOARD != "pca10056" ]] || sudo ports/nrf/drivers/bluetooth/download_ble_stack.sh)
   # For huzzah builds
   - if [[ $TRAVIS_BOARD = "feather_huzzah" ]]; then wget https://github.com/jepler/esp-open-sdk/releases/download/2018-06-10/xtensa-lx106-elf-standalone.tar.gz && tar xavf xtensa-lx106-elf-standalone.tar.gz; PATH=$(readlink -f xtensa-lx106-elf/bin):$PATH; fi
   # For coverage testing (upgrade is used to get latest urllib3 version)
diff --git a/extmod/vfs_fat.c b/extmod/vfs_fat.c
index e2982c7199..945ba9e804 100644
--- a/extmod/vfs_fat.c
+++ b/extmod/vfs_fat.c
@@ -320,7 +320,7 @@ STATIC mp_obj_t fat_vfs_stat(mp_obj_t vfs_in, mp_obj_t path_in) {
     } else {
         mode |= MP_S_IFREG;
     }
-    mp_int_t seconds = timeutils_seconds_since_2000(
+    mp_uint_t seconds = timeutils_seconds_since_epoch(
         1980 + ((fno.fdate >> 9) & 0x7f),
         (fno.fdate >> 5) & 0x0f,
         fno.fdate & 0x1f,
@@ -335,9 +335,9 @@ STATIC mp_obj_t fat_vfs_stat(mp_obj_t vfs_in, mp_obj_t path_in) {
     t->items[4] = MP_OBJ_NEW_SMALL_INT(0); // st_uid
     t->items[5] = MP_OBJ_NEW_SMALL_INT(0); // st_gid
     t->items[6] = mp_obj_new_int_from_uint(fno.fsize); // st_size
-    t->items[7] = MP_OBJ_NEW_SMALL_INT(seconds); // st_atime
-    t->items[8] = MP_OBJ_NEW_SMALL_INT(seconds); // st_mtime
-    t->items[9] = MP_OBJ_NEW_SMALL_INT(seconds); // st_ctime
+    t->items[7] = mp_obj_new_int_from_uint(seconds); // st_atime
+    t->items[8] = mp_obj_new_int_from_uint(seconds); // st_mtime
+    t->items[9] = mp_obj_new_int_from_uint(seconds); // st_ctime
 
     return MP_OBJ_FROM_PTR(t);
 }
diff --git a/lib/timeutils/timeutils.c b/lib/timeutils/timeutils.c
index eb3dc80d4b..b93a85dee9 100644
--- a/lib/timeutils/timeutils.c
+++ b/lib/timeutils/timeutils.c
@@ -158,6 +158,17 @@ mp_uint_t timeutils_seconds_since_2000(mp_uint_t year, mp_uint_t month,
         + (year - 2000) * 31536000;
 }
 
+void timeutils_seconds_since_epoch_to_struct_time(mp_uint_t t, timeutils_struct_time_t *tm) {
+    t -= EPOCH1970_EPOCH2000_DIFF_SECS;
+    timeutils_seconds_since_2000_to_struct_time(t, tm);
+}
+
+mp_uint_t timeutils_seconds_since_epoch(mp_uint_t year, mp_uint_t month, mp_uint_t date,
+                                        mp_uint_t hour, mp_uint_t minute, mp_uint_t second) {
+    mp_uint_t t = timeutils_seconds_since_2000(year, month, date, hour, minute, second);
+    return t + EPOCH1970_EPOCH2000_DIFF_SECS;
+}
+
 mp_uint_t timeutils_mktime(mp_uint_t year, mp_int_t month, mp_int_t mday,
     mp_int_t hours, mp_int_t minutes, mp_int_t seconds) {
 
@@ -211,5 +222,5 @@ mp_uint_t timeutils_mktime(mp_uint_t year, mp_int_t month, mp_int_t mday,
             year++;
         }
     }
-    return timeutils_seconds_since_2000(year, month, mday, hours, minutes, seconds);
+    return timeutils_seconds_since_epoch(year, month, mday, hours, minutes, seconds);
 }
diff --git a/lib/timeutils/timeutils.h b/lib/timeutils/timeutils.h
index 9b1abeb8f3..0ca6bb1679 100644
--- a/lib/timeutils/timeutils.h
+++ b/lib/timeutils/timeutils.h
@@ -27,6 +27,8 @@
 #ifndef MICROPY_INCLUDED_LIB_TIMEUTILS_TIMEUTILS_H
 #define MICROPY_INCLUDED_LIB_TIMEUTILS_TIMEUTILS_H
 
+#define EPOCH1970_EPOCH2000_DIFF_SECS    946684800
+
 typedef struct _timeutils_struct_time_t {
     uint16_t    tm_year;    // i.e. 2014
     uint8_t     tm_mon;     // 1..12
@@ -48,6 +50,11 @@ void timeutils_seconds_since_2000_to_struct_time(mp_uint_t t,
 mp_uint_t timeutils_seconds_since_2000(mp_uint_t year, mp_uint_t month,
     mp_uint_t date, mp_uint_t hour, mp_uint_t minute, mp_uint_t second);
 
+void timeutils_seconds_since_epoch_to_struct_time(mp_uint_t t, timeutils_struct_time_t *tm);
+
+mp_uint_t timeutils_seconds_since_epoch(mp_uint_t year, mp_uint_t month, mp_uint_t date,
+                                       mp_uint_t hour, mp_uint_t minute, mp_uint_t second);
+
 mp_uint_t timeutils_mktime(mp_uint_t year, mp_int_t month, mp_int_t mday,
     mp_int_t hours, mp_int_t minutes, mp_int_t seconds);
 
diff --git a/lib/tinyusb b/lib/tinyusb
index 7b35cd0203..583326e535 160000
--- a/lib/tinyusb
+++ b/lib/tinyusb
@@ -1 +1 @@
-Subproject commit 7b35cd0203bc409d7c1aefc075672103cb4a913e
+Subproject commit 583326e535454f16b06ebdb9cc06869602a5564c
diff --git a/ports/atmel-samd/fatfs_port.c b/ports/atmel-samd/fatfs_port.c
index e1eba350a2..67c6c9d35d 100644
--- a/ports/atmel-samd/fatfs_port.c
+++ b/ports/atmel-samd/fatfs_port.c
@@ -28,8 +28,13 @@
 #include "py/runtime.h"
 #include "lib/oofatfs/ff.h"        /* FatFs lower layer API */
 #include "lib/oofatfs/diskio.h"    /* FatFs lower layer API */
+#include "lib/timeutils/timeutils.h"
+#include "shared-bindings/rtc/RTC.h"
 
 DWORD get_fattime(void) {
-    // TODO(tannewt): Support the RTC.
-    return ((2016 - 1980) << 25) | ((9) << 21) | ((1) << 16) | ((16) << 11) | ((43) << 5) | (35 / 2);
+    timeutils_struct_time_t tm;
+    common_hal_rtc_get_time(&tm);
+
+    return ((tm.tm_year - 1980) << 25) | (tm.tm_mon << 21) | (tm.tm_mday << 16) |
+           (tm.tm_hour << 11)          | (tm.tm_min << 5)  | (tm.tm_sec >> 1);
 }
diff --git a/ports/nrf/README.md b/ports/nrf/README.md
index 6cc97703af..c21bd5d63b 100644
--- a/ports/nrf/README.md
+++ b/ports/nrf/README.md
@@ -36,9 +36,9 @@ the following links:
 > **NOTE**: These board specific readmes may be more up to date than the
   generic board-neutral documentation further down.
 
-* Adafruit [Feather nRF52](boards/feather52/README.md): 512KB Flash, 64KB SRAM
-* Adafruit [Feather nRF52840](boards/feather52840/README.md): 1MB Flash, 256KB SRAM
-* Nordic PCA10056 see [Feather nRF52840](boards/feather52840/README.md)
+* Adafruit [Feather nRF52](boards/feather_nrf52832/README.md): 512KB Flash, 64KB SRAM
+* Adafruit [Feather nRF52840](boards/feather_nrf52840_express/README.md): 1MB Flash, 256KB SRAM
+* Nordic PCA10056 see [Feather nRF52840](boards/pca10056/README.md)
 
 For all other board targets, see the generic notes below.
 
@@ -74,12 +74,12 @@ Note: further tuning of features to include in bluetooth or even setting up the
 
 ## Target Boards and Make Flags
 
-Target Board (BOARD) | Bluetooth Stack (SD)    | Bluetooth Support      | Flash Util
----------------------|-------------------------|------------------------|-------------------------------
-pca10040             | s132                    | Peripheral and Scanner | [Segger](#segger-targets)
-feather52832         | s132                    | Peripheral and Scanner | [UART DFU](#dfu-targets)
-pca10056             | s140                    | Peripheral and Scanner | [Segger](#segger-targets)
-feather52840         | s140                    | Peripheral and Scanner | [UART DFU](#dfu-targets)
+Target Board (BOARD)     | Bluetooth Stack (SD)    | Bluetooth Support      | Flash Util
+-------------------------|-------------------------|------------------------|-------------------------------
+pca10040                 | s132                    | Peripheral and Scanner | [Segger](#segger-targets)
+pca10056                 | s140                    | Peripheral and Scanner | [Segger](#segger-targets)
+feather_nrf52832         | s132                    | Peripheral and Scanner | [UART DFU](#dfu-targets)
+feather_nrf52840_express | s140                    | Peripheral and Scanner | UF2 bootloader
 
 ## Segger Targets
 
@@ -107,10 +107,10 @@ run follow command to install [adafruit-nrfutil](https://github.com/adafruit/Ada
 * dfu-gen: Generates a Firmware zip to be used by the DFU flash application.
 * dfu-flash: Triggers the DFU flash application to upload the firmware from the generated Firmware zip file.
 
-Example on how to generate and flash feather52832 target:
+Example on how to generate and flash feather_nrf52832 target:
 
-    make BOARD=feather52832 SD=s132
-    make BOARD=feather52832 SD=s132 dfu-gen dfu-flash
+    make BOARD=feather_nrf52832 SD=s132
+    make BOARD=feather_nrf52832 SD=s132 dfu-gen dfu-flash
 
 ## Bluetooth LE REPL
 
diff --git a/ports/nrf/boards/adafruit_nrf52840_s140_v6.ld b/ports/nrf/boards/adafruit_nrf52840_s140_v6.ld
index fbc87801f4..8a700d6109 100644
--- a/ports/nrf/boards/adafruit_nrf52840_s140_v6.ld
+++ b/ports/nrf/boards/adafruit_nrf52840_s140_v6.ld
@@ -1,5 +1,5 @@
 /*
-    GNU linker script for NRF52840 w/S140 6.0.0 SoftDevice
+    GNU linker script for NRF52840 w/S140 6.x.x SoftDevice
 
     MEMORY MAP
     ------------------------------------------------------------------------
@@ -17,7 +17,7 @@
     0x00000000..0x00000FFF   (4KB) Master Boot Record
 */
 
-/* Specify the memory areas (S140 6.0.0) */
+/* Specify the memory areas (S140 6.x.x) */
 MEMORY
 {
     FLASH (rx)      : ORIGIN = 0x00000000, LENGTH = 0x100000
diff --git a/ports/nrf/boards/feather52832/mpconfigboard.mk b/ports/nrf/boards/feather52832/mpconfigboard.mk
deleted file mode 100644
index a42decd89e..0000000000
--- a/ports/nrf/boards/feather52832/mpconfigboard.mk
+++ /dev/null
@@ -1,10 +0,0 @@
-MCU_SERIES = m4
-MCU_VARIANT = nrf52
-MCU_SUB_VARIANT = nrf52
-SD ?= s132
-SOFTDEV_VERSION ?= 2.0.1
-
-LD_FILE = boards/feather52832/custom_nrf52832_dfu_app_$(SOFTDEV_VERSION).ld
-
-BOOT_SETTING_ADDR = 0x7F000
-NRF_DEFINES += -DNRF52832_XXAA
diff --git a/ports/nrf/boards/feather52840/mpconfigboard.h b/ports/nrf/boards/feather52840/mpconfigboard.h
deleted file mode 100644
index ba9405a9d9..0000000000
--- a/ports/nrf/boards/feather52840/mpconfigboard.h
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2016 Glenn Ruben Bakke
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#define FEATHER52840
-
-#define MICROPY_HW_BOARD_NAME       "Feather52840"
-#define MICROPY_HW_MCU_NAME         "nRF52840"
-#define MICROPY_PY_SYS_PLATFORM     "Feather52840"
-
-#define MICROPY_HW_UART_RX          NRF_GPIO_PIN_MAP(0, 8)
-#define MICROPY_HW_UART_TX          NRF_GPIO_PIN_MAP(0, 6)
-#define MICROPY_HW_UART_HWFC        (0)
-
-#define PORT_HEAP_SIZE              (128 * 1024)
-#define CIRCUITPY_AUTORELOAD_DELAY_MS 500
diff --git a/ports/nrf/boards/feather52832/README.md b/ports/nrf/boards/feather_nrf52832/README.md
similarity index 94%
rename from ports/nrf/boards/feather52832/README.md
rename to ports/nrf/boards/feather_nrf52832/README.md
index 9fecee8069..b5acd63603 100644
--- a/ports/nrf/boards/feather52832/README.md
+++ b/ports/nrf/boards/feather_nrf52832/README.md
@@ -38,12 +38,12 @@ run following command to install [adafruit-nrfutil](https://github.com/adafruit/
 #### REPL over UART (default settings)
 
 To build a CircuitPython binary with default settings for the
-`feather52832` target enter:
+`feather_nrf52832` target enter:
 
-> **NOTE:** `BOARD=feather52832` is the default option and isn't stricly required.
+> **NOTE:** `BOARD=feather_nrf52832` is the default option and isn't stricly required.
 
 ```
-$ make BOARD=feather52832 V=1
+$ make BOARD=feather_nrf52832 V=1
 ```
 
 #### REPL over BLE UART (AKA 'NUS')
@@ -113,7 +113,7 @@ image, as described earlier in this readme.
 > The name of the serial port target will vary, depending on your OS.
 
 ```
-$ make BOARD=feather52832 SERIAL=/dev/tty.SLAB_USBtoUART dfu-gen dfu-flash
+$ make BOARD=feather_nrf52832 SERIAL=/dev/tty.SLAB_USBtoUART dfu-gen dfu-flash
 ```
 
 By default, CircuitPython will build with **BLE** support enabled using
@@ -121,7 +121,7 @@ By default, CircuitPython will build with **BLE** support enabled using
 SD family or version you can enter the optional fields as shown below:
 
 ```
-$ make BOARD=feather52832 SERIAL=/dev/tty.SLAB_USBtoUART SD=s132 SOFTDEV_VERSION=5.0.0 dfu-gen dfu-flash
+$ make BOARD=feather_nrf52832 SERIAL=/dev/tty.SLAB_USBtoUART SD=s132 SOFTDEV_VERSION=5.0.0 dfu-gen dfu-flash
 ```
 
 ## Working with CircuitPython
diff --git a/ports/nrf/boards/feather52832/board.c b/ports/nrf/boards/feather_nrf52832/board.c
similarity index 100%
rename from ports/nrf/boards/feather52832/board.c
rename to ports/nrf/boards/feather_nrf52832/board.c
diff --git a/ports/nrf/boards/feather52832/custom_nrf52832_dfu_app_2.0.1.ld b/ports/nrf/boards/feather_nrf52832/custom_nrf52832_dfu_app_2.0.1.ld
similarity index 100%
rename from ports/nrf/boards/feather52832/custom_nrf52832_dfu_app_2.0.1.ld
rename to ports/nrf/boards/feather_nrf52832/custom_nrf52832_dfu_app_2.0.1.ld
diff --git a/ports/nrf/boards/feather52832/custom_nrf52832_dfu_app_5.0.0.ld b/ports/nrf/boards/feather_nrf52832/custom_nrf52832_dfu_app_5.0.0.ld
similarity index 100%
rename from ports/nrf/boards/feather52832/custom_nrf52832_dfu_app_5.0.0.ld
rename to ports/nrf/boards/feather_nrf52832/custom_nrf52832_dfu_app_5.0.0.ld
diff --git a/ports/nrf/boards/feather52832/examples/ble_scan.py b/ports/nrf/boards/feather_nrf52832/examples/ble_scan.py
similarity index 100%
rename from ports/nrf/boards/feather52832/examples/ble_scan.py
rename to ports/nrf/boards/feather_nrf52832/examples/ble_scan.py
diff --git a/ports/nrf/boards/feather52832/examples/blinky.py b/ports/nrf/boards/feather_nrf52832/examples/blinky.py
similarity index 100%
rename from ports/nrf/boards/feather52832/examples/blinky.py
rename to ports/nrf/boards/feather_nrf52832/examples/blinky.py
diff --git a/ports/nrf/boards/feather52832/examples/i2c_scan.py b/ports/nrf/boards/feather_nrf52832/examples/i2c_scan.py
similarity index 100%
rename from ports/nrf/boards/feather52832/examples/i2c_scan.py
rename to ports/nrf/boards/feather_nrf52832/examples/i2c_scan.py
diff --git a/ports/nrf/boards/feather52832/examples/pulseio.py b/ports/nrf/boards/feather_nrf52832/examples/pulseio.py
similarity index 100%
rename from ports/nrf/boards/feather52832/examples/pulseio.py
rename to ports/nrf/boards/feather_nrf52832/examples/pulseio.py
diff --git a/ports/nrf/boards/feather52832/mpconfigboard.h b/ports/nrf/boards/feather_nrf52832/mpconfigboard.h
similarity index 100%
rename from ports/nrf/boards/feather52832/mpconfigboard.h
rename to ports/nrf/boards/feather_nrf52832/mpconfigboard.h
diff --git a/ports/nrf/boards/feather_nrf52832/mpconfigboard.mk b/ports/nrf/boards/feather_nrf52832/mpconfigboard.mk
new file mode 100644
index 0000000000..c370b724e7
--- /dev/null
+++ b/ports/nrf/boards/feather_nrf52832/mpconfigboard.mk
@@ -0,0 +1,11 @@
+MCU_SERIES = m4
+MCU_VARIANT = nrf52
+MCU_SUB_VARIANT = nrf52
+SD ?= s132
+SOFTDEV_VERSION ?= 2.0.1
+
+LD_FILE = boards/feather_nrf52832/custom_nrf52832_dfu_app_$(SOFTDEV_VERSION).ld
+BOOT_FILE = boards/feather_nrf52832/bootloader/feather52_bootloader_$(SOFTDEV_VERSION)_s132_single
+
+BOOT_SETTING_ADDR = 0x7F000
+NRF_DEFINES += -DNRF52832_XXAA
diff --git a/ports/nrf/boards/feather52832/pins.csv b/ports/nrf/boards/feather_nrf52832/pins.csv
similarity index 100%
rename from ports/nrf/boards/feather52832/pins.csv
rename to ports/nrf/boards/feather_nrf52832/pins.csv
diff --git a/ports/nrf/boards/feather52840/README.md b/ports/nrf/boards/feather_nrf52840_express/README.md
similarity index 100%
rename from ports/nrf/boards/feather52840/README.md
rename to ports/nrf/boards/feather_nrf52840_express/README.md
diff --git a/ports/nrf/boards/feather52840/board.c b/ports/nrf/boards/feather_nrf52840_express/board.c
similarity index 100%
rename from ports/nrf/boards/feather52840/board.c
rename to ports/nrf/boards/feather_nrf52840_express/board.c
diff --git a/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h b/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h
new file mode 100644
index 0000000000..ce21e73861
--- /dev/null
+++ b/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h
@@ -0,0 +1,75 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Glenn Ruben Bakke
+ * Copyright (c) 2018 Dan Halbert for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#define FEATHER52840
+
+#define MICROPY_HW_BOARD_NAME       "Adafruit Feather nRF52840 Express"
+#define MICROPY_HW_MCU_NAME         "nRF52840"
+#define MICROPY_PY_SYS_PLATFORM     "Feather52840"
+
+// #define MICROPY_HW_NEOPIXEL         NRF_GPIO_PIN_MAP(0, 13)
+
+// #define MICROPY_QSPI_DATA0          NRF_GPIO_PIN_MAP(1, 9)
+// #define MICROPY_QSPI_DATA1          NRF_GPIO_PIN_MAP(0, 11)
+// #define MICROPY_QSPI_DATA2          NRF_GPIO_PIN_MAP(0, 12)
+// #define MICROPY_QSPI_DATA3          NRF_GPIO_PIN_MAP(0, 14)
+// #define MICROPY_QSPI_SCK            NRF_GPIO_PIN_MAP(0, 8)
+// #define MICROPY_QSPI_CS             NRF_GPIO_PIN_MAP(1, 8)
+
+// #define MICROPY_HW_UART_RX          NRF_GPIO_PIN_MAP(0, 8)
+// #define MICROPY_HW_UART_TX          NRF_GPIO_PIN_MAP(0, 6)
+// #define MICROPY_HW_UART_HWFC        (0)
+
+#define CIRCUITPY_AUTORELOAD_DELAY_MS 500
+
+// If you change this, then make sure to update the linker scripts as well to
+// make sure you don't overwrite code
+#define PORT_HEAP_SIZE              (128 * 1024)
+// TODO #define CIRCUITPY_INTERNAL_NVM_SIZE 8192
+
+#define BOARD_FLASH_SIZE (FLASH_SIZE - 0x4000 - CIRCUITPY_INTERNAL_NVM_SIZE)
+
+// TODO #include "external_flash/devices.h"
+
+#define EXTERNAL_FLASH_DEVICE_COUNT 1
+#define EXTERNAL_FLASH_DEVICES GD25Q16C
+
+#define EXTERNAL_FLASH_QSPI_DUAL
+
+// TODO include "external_flash/external_flash.h"
+
+#define BOARD_HAS_CRYSTAL 1
+
+#define DEFAULT_I2C_BUS_SCL         NRF_GPIO_PIN_MAP(1, 11)
+#define DEFAULT_I2C_BUS_SDA         NRF_GPIO_PIN_MAP(1, 12)
+
+#define DEFAULT_SPI_BUS_SCK         NRF_GPIO_PIN_MAP(0, 20)
+#define DEFAULT_SPI_BUS_MOSI        NRF_GPIO_PIN_MAP(0, 23)
+#define DEFAULT_SPI_BUS_MISO        NRF_GPIO_PIN_MAP(0, 22)
+
+#define DEFAULT_UART_BUS_RX         NRF_GPIO_PIN_MAP(1, 0)
+#define DEFAULT_UART_BUS_TX         NRF_GPIO_PIN_MAP(0, 24)
diff --git a/ports/nrf/boards/feather52840/mpconfigboard.mk b/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.mk
similarity index 92%
rename from ports/nrf/boards/feather52840/mpconfigboard.mk
rename to ports/nrf/boards/feather_nrf52840_express/mpconfigboard.mk
index 1edc09a607..5c4fde4838 100644
--- a/ports/nrf/boards/feather52840/mpconfigboard.mk
+++ b/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.mk
@@ -2,7 +2,7 @@ MCU_SERIES = m4
 MCU_VARIANT = nrf52
 MCU_SUB_VARIANT = nrf52840
 SD ?= s140
-SOFTDEV_VERSION ?= 6.0.0
+SOFTDEV_VERSION ?= 6.1.0
 
 BOOT_SETTING_ADDR = 0xFF000
 
diff --git a/ports/nrf/boards/feather52840/pins.csv b/ports/nrf/boards/feather_nrf52840_express/pins.csv
similarity index 100%
rename from ports/nrf/boards/feather52840/pins.csv
rename to ports/nrf/boards/feather_nrf52840_express/pins.csv
diff --git a/ports/nrf/boards/nrf52_prefix.c b/ports/nrf/boards/nrf52_prefix.c
index e6c622da77..0c96eb61ef 100644
--- a/ports/nrf/boards/nrf52_prefix.c
+++ b/ports/nrf/boards/nrf52_prefix.c
@@ -4,7 +4,7 @@
 
 #include "py/obj.h"
 #include "py/mphal.h"
-#include "pin.h"
+#include "nrf_pin.h"
 
 #define PIN(p_name, p_port, p_pin, p_adc_channel) \
 { \
diff --git a/ports/nrf/boards/pca10056/mpconfigboard.mk b/ports/nrf/boards/pca10056/mpconfigboard.mk
index 1edc09a607..5c4fde4838 100644
--- a/ports/nrf/boards/pca10056/mpconfigboard.mk
+++ b/ports/nrf/boards/pca10056/mpconfigboard.mk
@@ -2,7 +2,7 @@ MCU_SERIES = m4
 MCU_VARIANT = nrf52
 MCU_SUB_VARIANT = nrf52840
 SD ?= s140
-SOFTDEV_VERSION ?= 6.0.0
+SOFTDEV_VERSION ?= 6.1.0
 
 BOOT_SETTING_ADDR = 0xFF000
 
diff --git a/ports/nrf/common-hal/board/__init__.c b/ports/nrf/common-hal/board/__init__.c
index 257b8108d4..287f546d5c 100644
--- a/ports/nrf/common-hal/board/__init__.c
+++ b/ports/nrf/common-hal/board/__init__.c
@@ -25,4 +25,4 @@
  */
 
 // Pins aren't actually defined here. They are in the board specific directory
-// such as boards/feather52832/pins.csv
+// such as boards/feather_nrf52832/pins.csv
diff --git a/ports/nrf/common-hal/microcontroller/Pin.h b/ports/nrf/common-hal/microcontroller/Pin.h
index 66cd011da2..1694a82493 100644
--- a/ports/nrf/common-hal/microcontroller/Pin.h
+++ b/ports/nrf/common-hal/microcontroller/Pin.h
@@ -27,7 +27,7 @@
 #ifndef MICROPY_INCLUDED_NRF_COMMON_HAL_MICROCONTROLLER_PIN_H
 #define MICROPY_INCLUDED_NRF_COMMON_HAL_MICROCONTROLLER_PIN_H
 
-#include "pin.h"
+#include "nrf_pin.h"
 #include "py/mphal.h"
 
 #define mcu_pin_obj_t pin_obj_t
diff --git a/ports/nrf/drivers/bluetooth/download_ble_stack.sh b/ports/nrf/drivers/bluetooth/download_ble_stack.sh
index 52bd4b22dc..385dbb451b 100755
--- a/ports/nrf/drivers/bluetooth/download_ble_stack.sh
+++ b/ports/nrf/drivers/bluetooth/download_ble_stack.sh
@@ -35,18 +35,16 @@ function download_s132_nrf52_5_0_0
     cd -
 }
 
-function download_s140_nrf52_6_0_0
+function download_s140_nrf52_6_1_0
 {
     echo ""
     echo "####################################"
-    echo "### Downloading s140_nrf52_6.0.0 ###"
+    echo "### Downloading s140_nrf52_6.1.0 ###"
     echo "####################################"
     echo ""
-
-    mkdir -p "${1}/s140_nrf52_6.0.0"
-    cd "${1}/s140_nrf52_6.0.0"
-
-    wget https://www.nordicsemi.com/eng/nordic/download_resource/60624/20/49271410/116072
+     mkdir -p "${1}/s140_nrf52_6.1.0"
+    cd "${1}/s140_nrf52_6.1.0"
+     wget https://www.nordicsemi.com/eng/nordic/download_resource/60624/25/88218841/116072
     mv 116072 temp.zip
     unzip -u temp.zip
     rm temp.zip
@@ -59,15 +57,15 @@ if [ $# -eq 0 ]; then
     echo "No Bluetooth LE stack defined, downloading all."
     download_s132_nrf52_2_0_1 "${SCRIPT_DIR}"
     download_s132_nrf52_5_0_0 "${SCRIPT_DIR}"
-    download_s140_nrf52_6_0_0 "${SCRIPT_DIR}"
+    download_s140_nrf52_6_1_0 "${SCRIPT_DIR}"
 else
     case $1 in
         "s132_nrf52_2_0_1" )
             download_s132_nrf52_2_0_1 "${SCRIPT_DIR}" ;;
         "s132_nrf52_5_0_0" )
             download_s132_nrf52_5_0_0 "${SCRIPT_DIR}" ;;
-        "s140_nrf52_6_0_0" )
-            download_s140_nrf52_6_0_0 "${SCRIPT_DIR}" ;;
+        "s140_nrf52_6_1_0" )
+            download_s140_nrf52_6_1_0 "${SCRIPT_DIR}" ;;
     esac
 fi
 
diff --git a/ports/nrf/pin.h b/ports/nrf/nrf_pin.h
similarity index 100%
rename from ports/nrf/pin.h
rename to ports/nrf/nrf_pin.h
diff --git a/ports/nrf/supervisor/serial.c b/ports/nrf/supervisor/serial.c
index 4256b39f1c..a822dc9936 100644
--- a/ports/nrf/supervisor/serial.c
+++ b/ports/nrf/supervisor/serial.c
@@ -30,7 +30,7 @@
 #include "ble_uart.h"
 #else
 #include "nrf_gpio.h"
-#include "pin.h"
+#include "nrf_pin.h"
 #endif
 
 #if !defined( NRF52840_XXAA) || ( defined(CFG_HWUART_FOR_SERIAL) && CFG_HWUART_FOR_SERIAL == 1 )
diff --git a/ports/nrf/usb/usb.c b/ports/nrf/usb/usb.c
index 7168cf53d1..f8b5fd6632 100644
--- a/ports/nrf/usb/usb.c
+++ b/ports/nrf/usb/usb.c
@@ -58,7 +58,7 @@ void usb_init(void) {
 
         sd_power_usbregstatus_get(&usb_reg);
     }else
-#else
+#endif
     {
         // Power module init
         const nrfx_power_config_t pwr_cfg = { 0 };
@@ -72,7 +72,6 @@ void usb_init(void) {
 
         usb_reg = NRF_POWER->USBREGSTATUS;
     }
-#endif
 
     if ( usb_reg & POWER_USBREGSTATUS_VBUSDETECT_Msk ) {
         tusb_hal_nrf_power_event(NRFX_POWER_USB_EVT_DETECTED);
@@ -82,6 +81,21 @@ void usb_init(void) {
         tusb_hal_nrf_power_event(NRFX_POWER_USB_EVT_READY);
     }
 
+    // create serial number based on device unique id
+    extern uint16_t usb_desc_str_serial[1 + 16];
+
+    char nibble_to_hex[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+
+    for (int i = 0; i < 2; i++) {
+        for (int j = 0; j < 8; j++) {
+            uint8_t nibble = (NRF_FICR->DEVICEID[i] >> j * 4) & 0xf;
+
+            // Invert order since it is LE, +1 for skipping descriptor header
+            uint8_t  const idx = (15 - (i * 8 + j)) + 1;
+            usb_desc_str_serial[idx] = nibble_to_hex[nibble];
+        }
+    }
+
     tusb_init();
 
 #if MICROPY_KBD_EXCEPTION
diff --git a/ports/nrf/usb/usb_desc.c b/ports/nrf/usb/usb_desc.c
index 31f80b80d2..10d603528b 100644
--- a/ports/nrf/usb/usb_desc.c
+++ b/ports/nrf/usb/usb_desc.c
@@ -78,6 +78,8 @@ enum {
 // STRING DESCRIPTORS
 //--------------------------------------------------------------------+
 
+uint16_t usb_desc_str_serial[1+16] = { TUD_DESC_STR_HEADER(16) };
+
 // array of pointer to string descriptors
 uint16_t const * const string_desc_arr [] =
 {
@@ -91,7 +93,7 @@ uint16_t const * const string_desc_arr [] =
     TUD_DESC_STRCONV('C','i','r','c','u','i','t','P','y',' ','n','R','F','5','2'),
 
     // 3 Serials TODO use chip ID
-    TUD_DESC_STRCONV('1', '2', '3', '4', '5'),
+    usb_desc_str_serial,
 
     // 4 CDC Interface
     TUD_DESC_STRCONV('C','i','r','c','u','i','t','P','y',' ','S','e','r','i','a','l'),
diff --git a/py/vm.c b/py/vm.c
index 72d0d0d60a..b5f53ee9a0 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -136,7 +136,7 @@ mp_vm_return_kind_t mp_execute_bytecode(mp_code_state_t *code_state, volatile mp
     #define ENTRY(op) entry_##op
     #define ENTRY_DEFAULT entry_default
 #else
-    #define DISPATCH() goto dispatch_loop
+    #define DISPATCH() break
     #define DISPATCH_WITH_PEND_EXC_CHECK() goto pending_exception_check
     #define ENTRY(op) case op
     #define ENTRY_DEFAULT default
diff --git a/shared-bindings/time/__init__.c b/shared-bindings/time/__init__.c
index 83bbbe2cd4..4d95545690 100644
--- a/shared-bindings/time/__init__.c
+++ b/shared-bindings/time/__init__.c
@@ -36,8 +36,6 @@
 #include "shared-bindings/time/__init__.h"
 #include "supervisor/shared/translate.h"
 
-#define EPOCH1970_EPOCH2000_DIFF_SECS    946684800
-
 //| :mod:`time` --- time and timing related functions
 //| ========================================================
 //|
@@ -142,9 +140,9 @@ const mp_obj_namedtuple_type_t struct_time_type_obj = {
 
 mp_obj_t struct_time_from_tm(timeutils_struct_time_t *tm) {
     timeutils_struct_time_t tmp;
-    mp_uint_t secs = timeutils_seconds_since_2000(tm->tm_year, tm->tm_mon, tm->tm_mday,
+    mp_uint_t secs = timeutils_seconds_since_epoch(tm->tm_year, tm->tm_mon, tm->tm_mday,
                                                   tm->tm_hour, tm->tm_min, tm->tm_sec);
-    timeutils_seconds_since_2000_to_struct_time(secs, &tmp);
+    timeutils_seconds_since_epoch_to_struct_time(secs, &tmp);
     tm->tm_wday = tmp.tm_wday;
     tm->tm_yday = tmp.tm_yday;
 
@@ -202,9 +200,9 @@ mp_obj_t MP_WEAK rtc_get_time_source_time(void) {
 STATIC mp_obj_t time_time(void) {
     timeutils_struct_time_t tm;
     struct_time_to_tm(rtc_get_time_source_time(), &tm);
-    mp_uint_t secs = timeutils_seconds_since_2000(tm.tm_year, tm.tm_mon, tm.tm_mday,
+    mp_uint_t secs = timeutils_seconds_since_epoch(tm.tm_year, tm.tm_mon, tm.tm_mday,
                                                   tm.tm_hour, tm.tm_min, tm.tm_sec);
-    return mp_obj_new_int_from_uint(secs + EPOCH1970_EPOCH2000_DIFF_SECS);
+    return mp_obj_new_int_from_uint(secs);
 }
 MP_DEFINE_CONST_FUN_OBJ_0(time_time_obj, time_time);
 
@@ -228,7 +226,7 @@ STATIC mp_obj_t time_localtime(size_t n_args, const mp_obj_t *args) {
         mp_raise_msg(&mp_type_OverflowError, translate("timestamp out of range for platform time_t"));
 
     timeutils_struct_time_t tm;
-    timeutils_seconds_since_2000_to_struct_time(secs - EPOCH1970_EPOCH2000_DIFF_SECS, &tm);
+    timeutils_seconds_since_epoch_to_struct_time(secs, &tm);
 
     return struct_time_from_tm(&tm);
 }
@@ -262,7 +260,7 @@ STATIC mp_obj_t time_mktime(mp_obj_t t) {
 
     mp_uint_t secs = timeutils_mktime(mp_obj_get_int(elem[0]), mp_obj_get_int(elem[1]), mp_obj_get_int(elem[2]),
                                       mp_obj_get_int(elem[3]), mp_obj_get_int(elem[4]), mp_obj_get_int(elem[5]));
-    return mp_obj_new_int_from_uint(secs + EPOCH1970_EPOCH2000_DIFF_SECS);
+    return mp_obj_new_int_from_uint(secs);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(time_mktime_obj, time_mktime);
 #endif // MICROPY_LONGINT_IMPL
diff --git a/tests/extmod/vfs_fat_ramdisk.py.exp b/tests/extmod/vfs_fat_ramdisk.py.exp
index ecae81589a..704408cd0b 100644
--- a/tests/extmod/vfs_fat_ramdisk.py.exp
+++ b/tests/extmod/vfs_fat_ramdisk.py.exp
@@ -5,7 +5,7 @@ statvfs: (512, 512, 16, 16, 16, 0, 0, 0, 0, 255)
 getcwd: /
 True
 [('foo_file.txt', 32768, 0, 6)]
-stat root: (16384, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+stat root: (16384, 0, 0, 0, 0, 0, 0, 946684800, 946684800, 946684800)
 stat file: (32768, 0, 0, 0, 0, 0, 6)
 True
 True
diff --git a/tools/build_adafruit_bins.sh b/tools/build_adafruit_bins.sh
index 13d65e317b..c45521f7a8 100755
--- a/tools/build_adafruit_bins.sh
+++ b/tools/build_adafruit_bins.sh
@@ -2,7 +2,31 @@ rm -rf ports/atmel-samd/build*
 rm -rf ports/esp8266/build*
 rm -rf ports/nrf/build*
 
-ATMEL_BOARDS="arduino_zero circuitplayground_express circuitplayground_express_crickit feather_radiofruit_zigbee feather_m0_basic feather_m0_adalogger itsybitsy_m0_express itsybitsy_m4_express feather_m0_rfm69 feather_m0_rfm9x feather_m0_express feather_m0_express_crickit feather_m4_express metro_m0_express metro_m4_express pirkey_m0 trinket_m0 gemma_m0 feather52832 feather_huzzah pca10056 hallowing_m0_express"
+HW_BOARDS="\
+arduino_zero \
+circuitplayground_express \
+circuitplayground_express_crickit \
+feather_huzzah \
+feather_m0_adalogger \
+feather_m0_basic \
+feather_m0_express \
+feather_m0_express_crickit \
+feather_m0_rfm69 \
+feather_m0_rfm9x \
+feather_m4_express \
+feather_nrf52832 \
+feather_nrf52840_express \
+pca10056 \
+feather_radiofruit_zigbee \
+gemma_m0 \
+hallowing_m0_express \
+itsybitsy_m0_express \
+itsybitsy_m4_express \
+metro_m0_express \
+metro_m4_express \
+pirkey_m0 \
+trinket_m0 \
+"
 ROSIE_SETUPS="rosie-ci"
 
 PARALLEL="-j 5"
@@ -11,7 +35,7 @@ if [ "$TRAVIS" == "true" ]; then
 fi
 
 if [ -z "$TRAVIS_BOARD" ]; then
-    boards=$ATMEL_BOARDS
+    boards=$HW_BOARDS
 else
     boards=$TRAVIS_BOARD
 fi
@@ -41,16 +65,21 @@ for board in $boards; do
             (( exit_status = exit_status || $? ))
             temp_filename=ports/esp8266/build/firmware-combined.bin
             extension=bin
-        elif [ $board == "feather52832" ]; then
-            make $PARALLEL -C ports/nrf TRANSLATION=$language BOARD=feather52832
+        elif [ $board == "feather_nrf52832" ]; then
+            make $PARALLEL -C ports/nrf TRANSLATION=$language BOARD=feather_nrf52832
             (( exit_status = exit_status || $? ))
             temp_filename=ports/nrf/build-$board-s132/firmware.bin
             extension=bin
+        elif [ $board == "feather_nrf52840_express" ]; then
+            make $PARALLEL -C ports/nrf TRANSLATION=$language BOARD=feather_nrf52840_express SD=s140
+            (( exit_status = exit_status || $? ))
+            temp_filename=ports/nrf/build-$board-s140/firmware.uf2
+            extension=uf2
         elif [ $board == "pca10056" ]; then
             make $PARALLEL -C ports/nrf TRANSLATION=$language BOARD=pca10056 SD=s140
             (( exit_status = exit_status || $? ))
-            temp_filename=ports/nrf/build-$board-s140/firmware.bin
-            extension=bin
+            temp_filename=ports/nrf/build-$board-s140/firmware.uf2
+            extension=uf2
         else
             time make $PARALLEL -C ports/atmel-samd TRANSLATION=$language BOARD=$board
             (( exit_status = exit_status || $? ))