diff --git a/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h b/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h
index 3c1895dd24..64b22acd57 100644
--- a/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h
@@ -3,15 +3,15 @@
 
 #define CIRCUITPY_MCU_FAMILY samd51
 
-// This is for Rev C which is green
+// Rev E
 
-#define MICROPY_HW_NEOPIXEL (&pin_PB23)
+#define MICROPY_HW_NEOPIXEL (&pin_PB03)
 
 // These are pins not to reset.
-// QSPI Data pins and TX LED
-#define MICROPY_PORT_A (PORT_PA08 | PORT_PA09)
-// RX LED, QSPI CS, QSPI SCK and NeoPixel pin
-#define MICROPY_PORT_B (PORT_PB10 | PORT_PB11 | PORT_PB23 )
+// QSPI Data pins
+#define MICROPY_PORT_A (PORT_PA08 | PORT_PA09 | PORT_PA10 | PORT_PA11)
+// QSPI CS, QSPI SCK and NeoPixel pin
+#define MICROPY_PORT_B (PORT_PB03 | PORT_PB10 | PORT_PB11)
 #define MICROPY_PORT_C (0)
 #define MICROPY_PORT_D (0)
 
@@ -25,8 +25,8 @@
 
 #include "external_flash/devices.h"
 
-#define EXTERNAL_FLASH_DEVICE_COUNT 2
-#define EXTERNAL_FLASH_DEVICES W25Q16FW, GD25Q16C
+#define EXTERNAL_FLASH_DEVICE_COUNT 1
+#define EXTERNAL_FLASH_DEVICES GD25Q16C
 
 #define EXTERNAL_FLASH_QSPI_DUAL
 
@@ -36,8 +36,8 @@
 #define DEFAULT_I2C_BUS_SDA (&pin_PA12)
 
 #define DEFAULT_SPI_BUS_SCK (&pin_PA17)
-#define DEFAULT_SPI_BUS_MOSI (&pin_PA19)
-#define DEFAULT_SPI_BUS_MISO (&pin_PA18)
+#define DEFAULT_SPI_BUS_MOSI (&pin_PB23)
+#define DEFAULT_SPI_BUS_MISO (&pin_PB22)
 
-#define DEFAULT_UART_BUS_RX (&pin_PA07)
-#define DEFAULT_UART_BUS_TX (&pin_PA04)
+#define DEFAULT_UART_BUS_RX (&pin_PB17)
+#define DEFAULT_UART_BUS_TX (&pin_PB16)
diff --git a/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.mk b/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.mk
index 01385bdc6c..e19a27b88f 100644
--- a/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/feather_m4_express/mpconfigboard.mk
@@ -7,5 +7,5 @@ USB_MANUFACTURER = "Adafruit Industries LLC"
 QSPI_FLASH_FILESYSTEM = 1
 LONGINT_IMPL = MPZ
 
-CHIP_VARIANT = SAMD51G19A
+CHIP_VARIANT = SAMD51J19A
 CHIP_FAMILY = samd51
diff --git a/ports/atmel-samd/boards/feather_m4_express/pins.c b/ports/atmel-samd/boards/feather_m4_express/pins.c
index 6807a901d5..bc3cb1f477 100644
--- a/ports/atmel-samd/boards/feather_m4_express/pins.c
+++ b/ports/atmel-samd/boards/feather_m4_express/pins.c
@@ -1,4 +1,4 @@
-#include "samd21_pins.h"
+#include "samd51_pins.h"
 #include "board_busses.h"
 
 STATIC const mp_rom_map_elem_t board_global_dict_table[] = {
@@ -6,27 +6,26 @@ STATIC const mp_rom_map_elem_t board_global_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_A1), MP_ROM_PTR(&pin_PA05) },
     { MP_ROM_QSTR(MP_QSTR_A2), MP_ROM_PTR(&pin_PB08) },
     { MP_ROM_QSTR(MP_QSTR_A3), MP_ROM_PTR(&pin_PB09) },
-    { MP_ROM_QSTR(MP_QSTR_A4), MP_ROM_PTR(&pin_PA06) },
-    { MP_ROM_QSTR(MP_QSTR_A5), MP_ROM_PTR(&pin_PA10) },
-    { MP_ROM_QSTR(MP_QSTR_AREF), MP_ROM_PTR(&pin_PA03) },
-
+    { MP_ROM_QSTR(MP_QSTR_A4), MP_ROM_PTR(&pin_PA04) },
+    { MP_ROM_QSTR(MP_QSTR_A5), MP_ROM_PTR(&pin_PA06) },
     { MP_ROM_QSTR(MP_QSTR_SCK), MP_ROM_PTR(&pin_PA17) },
-    { MP_ROM_QSTR(MP_QSTR_MOSI), MP_ROM_PTR(&pin_PA19) },
-    { MP_ROM_QSTR(MP_QSTR_MISO), MP_ROM_PTR(&pin_PA18) },
-    { MP_ROM_QSTR(MP_QSTR_D0), MP_ROM_PTR(&pin_PA07) },
-    { MP_ROM_QSTR(MP_QSTR_RX), MP_ROM_PTR(&pin_PA07) },
-    { MP_ROM_QSTR(MP_QSTR_D1), MP_ROM_PTR(&pin_PA04) },
-    { MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_PTR(&pin_PA04) },
+    { MP_ROM_QSTR(MP_QSTR_MOSI), MP_ROM_PTR(&pin_PB23) },
+    { MP_ROM_QSTR(MP_QSTR_MISO), MP_ROM_PTR(&pin_PB22) },
+    { MP_ROM_QSTR(MP_QSTR_D0), MP_ROM_PTR(&pin_PB17) },
+    { MP_ROM_QSTR(MP_QSTR_RX), MP_ROM_PTR(&pin_PB17) },
+    { MP_ROM_QSTR(MP_QSTR_D1), MP_ROM_PTR(&pin_PB16) },
+    { MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_PTR(&pin_PB16) },
     { MP_ROM_QSTR(MP_QSTR_SDA), MP_ROM_PTR(&pin_PA12) },
     { MP_ROM_QSTR(MP_QSTR_SCL), MP_ROM_PTR(&pin_PA13) },
-    { MP_ROM_QSTR(MP_QSTR_D5), MP_ROM_PTR(&pin_PA14) },
-    { MP_ROM_QSTR(MP_QSTR_D6), MP_ROM_PTR(&pin_PA15) },
-    { MP_ROM_QSTR(MP_QSTR_D9), MP_ROM_PTR(&pin_PA16) },
+    { MP_ROM_QSTR(MP_QSTR_D5), MP_ROM_PTR(&pin_PA16) },
+    { MP_ROM_QSTR(MP_QSTR_D6), MP_ROM_PTR(&pin_PA18) },
+    { MP_ROM_QSTR(MP_QSTR_D9), MP_ROM_PTR(&pin_PA19) },
     { MP_ROM_QSTR(MP_QSTR_D10), MP_ROM_PTR(&pin_PA20) },
     { MP_ROM_QSTR(MP_QSTR_D11), MP_ROM_PTR(&pin_PA21) },
     { MP_ROM_QSTR(MP_QSTR_D12), MP_ROM_PTR(&pin_PA22) },
     { MP_ROM_QSTR(MP_QSTR_D13), MP_ROM_PTR(&pin_PA23) },
-    { MP_ROM_QSTR(MP_QSTR_NEOPIXEL), MP_ROM_PTR(&pin_PB23) },
+    { MP_ROM_QSTR(MP_QSTR_NEOPIXEL), MP_ROM_PTR(&pin_PB03) },
+    { MP_ROM_QSTR(MP_QSTR_VOLTAGE_MONITOR), MP_ROM_PTR(&pin_PB01) },
     { MP_ROM_QSTR(MP_QSTR_I2C), MP_ROM_PTR(&board_i2c_obj) },
     { MP_ROM_QSTR(MP_QSTR_SPI), MP_ROM_PTR(&board_spi_obj) },
     { MP_ROM_QSTR(MP_QSTR_UART), MP_ROM_PTR(&board_uart_obj) },
diff --git a/ports/atmel-samd/boards/itsybitsy_m4_express/pins.c b/ports/atmel-samd/boards/itsybitsy_m4_express/pins.c
index 084250b311..fdcf039e64 100644
--- a/ports/atmel-samd/boards/itsybitsy_m4_express/pins.c
+++ b/ports/atmel-samd/boards/itsybitsy_m4_express/pins.c
@@ -28,8 +28,6 @@ STATIC const mp_rom_map_elem_t board_global_dict_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_SDA), MP_ROM_PTR(&pin_PA12) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SCL), MP_ROM_PTR(&pin_PA13) },
 
-    { MP_OBJ_NEW_QSTR(MP_QSTR_AREF), MP_ROM_PTR(&pin_PA03) },
-
     { MP_OBJ_NEW_QSTR(MP_QSTR_SCK), MP_ROM_PTR(&pin_PA01) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_MOSI), MP_ROM_PTR(&pin_PA00) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_MISO), MP_ROM_PTR(&pin_PB23) },
diff --git a/ports/atmel-samd/boards/metro_m4_express/pins.c b/ports/atmel-samd/boards/metro_m4_express/pins.c
index 95a97d825f..8dc0f25d6b 100644
--- a/ports/atmel-samd/boards/metro_m4_express/pins.c
+++ b/ports/atmel-samd/boards/metro_m4_express/pins.c
@@ -32,8 +32,6 @@ STATIC const mp_map_elem_t board_global_dict_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_SDA), (mp_obj_t)&pin_PB02 },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SCL), (mp_obj_t)&pin_PB03 },
 
-    { MP_OBJ_NEW_QSTR(MP_QSTR_AREF), (mp_obj_t)&pin_PA03 },
-
     { MP_OBJ_NEW_QSTR(MP_QSTR_NEOPIXEL), (mp_obj_t)&pin_PB22 },
 
     { MP_OBJ_NEW_QSTR(MP_QSTR_SCK), (mp_obj_t)&pin_PA13 },