diff --git a/lib/tinyusb b/lib/tinyusb
index 583326e535..a660fb0cfc 160000
--- a/lib/tinyusb
+++ b/lib/tinyusb
@@ -1 +1 @@
-Subproject commit 583326e535454f16b06ebdb9cc06869602a5564c
+Subproject commit a660fb0cfc8641d5645d1cdea76027266b278388
diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index 82a0f95e69..232ad7c46c 100644
--- a/locale/circuitpython.pot
+++ b/locale/circuitpython.pot
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-10-01 18:52-0400\n"
+"POT-Creation-Date: 2018-10-03 23:15+0700\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -378,10 +378,12 @@ msgid "bytes > 8 bits not supported"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:72
+#: ports/nrf/common-hal/busio/UART.c:82
 msgid "tx and rx cannot both be None"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:145
+#: ports/nrf/common-hal/busio/UART.c:115
 msgid "Failed to allocate RX buffer"
 msgstr ""
 
@@ -390,10 +392,12 @@ msgid "Could not initialize UART"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:240
+#: ports/nrf/common-hal/busio/UART.c:149
 msgid "No RX pin"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:294
+#: ports/nrf/common-hal/busio/UART.c:195
 msgid "No TX pin"
 msgstr ""
 
@@ -698,12 +702,29 @@ msgstr ""
 msgid "All SPI peripherals are in use"
 msgstr ""
 
-#: ports/nrf/common-hal/busio/UART.c:43 ports/nrf/common-hal/busio/UART.c:47
-#: ports/nrf/common-hal/busio/UART.c:51 ports/nrf/common-hal/busio/UART.c:60
-#: ports/nrf/common-hal/busio/UART.c:66 ports/nrf/common-hal/busio/UART.c:71
-#: ports/nrf/common-hal/busio/UART.c:76 ports/nrf/common-hal/busio/UART.c:81
-#: ports/nrf/common-hal/busio/UART.c:86 ports/nrf/common-hal/busio/UART.c:90
-msgid "busio.UART not yet implemented"
+#: ports/nrf/common-hal/busio/SPI.c:176
+msgid "Baud rate too high for this SPI peripheral"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:48
+#, c-format
+msgid "error = 0x%08lX"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:86
+msgid "Invalid buffer size"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:90
+msgid "Odd parity is not supported"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:322 ports/nrf/common-hal/busio/UART.c:326
+#: ports/nrf/common-hal/busio/UART.c:331 ports/nrf/common-hal/busio/UART.c:336
+#: ports/nrf/common-hal/busio/UART.c:342 ports/nrf/common-hal/busio/UART.c:347
+#: ports/nrf/common-hal/busio/UART.c:352 ports/nrf/common-hal/busio/UART.c:356
+#: ports/nrf/common-hal/busio/UART.c:364
+msgid "busio.UART not available"
 msgstr ""
 
 #: ports/nrf/common-hal/microcontroller/Processor.c:49
diff --git a/locale/de_DE.po b/locale/de_DE.po
index cbd981e489..790b23442b 100644
--- a/locale/de_DE.po
+++ b/locale/de_DE.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-10-01 18:44-0400\n"
+"POT-Creation-Date: 2018-10-03 23:15+0700\n"
 "PO-Revision-Date: 2018-07-27 11:55-0700\n"
 "Last-Translator: Sebastian Plamauer\n"
 "Language-Team: \n"
@@ -387,10 +387,12 @@ msgid "bytes > 8 bits not supported"
 msgstr "bytes mit merh als 8 bits werden nicht unterstützt"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:72
+#: ports/nrf/common-hal/busio/UART.c:82
 msgid "tx and rx cannot both be None"
 msgstr "tx und rx können nicht beide None sein"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:145
+#: ports/nrf/common-hal/busio/UART.c:115
 msgid "Failed to allocate RX buffer"
 msgstr "Konnte keinen RX Buffer allozieren"
 
@@ -399,10 +401,12 @@ msgid "Could not initialize UART"
 msgstr "Konnte UART nicht initialisieren"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:240
+#: ports/nrf/common-hal/busio/UART.c:149
 msgid "No RX pin"
 msgstr "Kein RX Pin"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:294
+#: ports/nrf/common-hal/busio/UART.c:195
 msgid "No TX pin"
 msgstr "Kein TX Pin"
 
@@ -709,12 +713,31 @@ msgstr "Alle timer werden benutzt"
 msgid "All SPI peripherals are in use"
 msgstr "Alle timer werden benutzt"
 
-#: ports/nrf/common-hal/busio/UART.c:43 ports/nrf/common-hal/busio/UART.c:47
-#: ports/nrf/common-hal/busio/UART.c:51 ports/nrf/common-hal/busio/UART.c:60
-#: ports/nrf/common-hal/busio/UART.c:66 ports/nrf/common-hal/busio/UART.c:71
-#: ports/nrf/common-hal/busio/UART.c:76 ports/nrf/common-hal/busio/UART.c:81
-#: ports/nrf/common-hal/busio/UART.c:86 ports/nrf/common-hal/busio/UART.c:90
-msgid "busio.UART not yet implemented"
+#: ports/nrf/common-hal/busio/SPI.c:176
+msgid "Baud rate too high for this SPI peripheral"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:48
+#, c-format
+msgid "error = 0x%08lX"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:86
+#, fuzzy
+msgid "Invalid buffer size"
+msgstr "ungültiger dupterm index"
+
+#: ports/nrf/common-hal/busio/UART.c:90
+#, fuzzy
+msgid "Odd parity is not supported"
+msgstr "bytes mit merh als 8 bits werden nicht unterstützt"
+
+#: ports/nrf/common-hal/busio/UART.c:322 ports/nrf/common-hal/busio/UART.c:326
+#: ports/nrf/common-hal/busio/UART.c:331 ports/nrf/common-hal/busio/UART.c:336
+#: ports/nrf/common-hal/busio/UART.c:342 ports/nrf/common-hal/busio/UART.c:347
+#: ports/nrf/common-hal/busio/UART.c:352 ports/nrf/common-hal/busio/UART.c:356
+#: ports/nrf/common-hal/busio/UART.c:364
+msgid "busio.UART not available"
 msgstr ""
 
 #: ports/nrf/common-hal/microcontroller/Processor.c:49
diff --git a/locale/en_US.po b/locale/en_US.po
index ca9e56444d..6e576f1504 100644
--- a/locale/en_US.po
+++ b/locale/en_US.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-10-01 18:44-0400\n"
+"POT-Creation-Date: 2018-10-03 23:15+0700\n"
 "PO-Revision-Date: 2018-07-27 11:55-0700\n"
 "Last-Translator: \n"
 "Language-Team: \n"
@@ -378,10 +378,12 @@ msgid "bytes > 8 bits not supported"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:72
+#: ports/nrf/common-hal/busio/UART.c:82
 msgid "tx and rx cannot both be None"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:145
+#: ports/nrf/common-hal/busio/UART.c:115
 msgid "Failed to allocate RX buffer"
 msgstr ""
 
@@ -390,10 +392,12 @@ msgid "Could not initialize UART"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:240
+#: ports/nrf/common-hal/busio/UART.c:149
 msgid "No RX pin"
 msgstr ""
 
 #: ports/atmel-samd/common-hal/busio/UART.c:294
+#: ports/nrf/common-hal/busio/UART.c:195
 msgid "No TX pin"
 msgstr ""
 
@@ -698,12 +702,29 @@ msgstr ""
 msgid "All SPI peripherals are in use"
 msgstr ""
 
-#: ports/nrf/common-hal/busio/UART.c:43 ports/nrf/common-hal/busio/UART.c:47
-#: ports/nrf/common-hal/busio/UART.c:51 ports/nrf/common-hal/busio/UART.c:60
-#: ports/nrf/common-hal/busio/UART.c:66 ports/nrf/common-hal/busio/UART.c:71
-#: ports/nrf/common-hal/busio/UART.c:76 ports/nrf/common-hal/busio/UART.c:81
-#: ports/nrf/common-hal/busio/UART.c:86 ports/nrf/common-hal/busio/UART.c:90
-msgid "busio.UART not yet implemented"
+#: ports/nrf/common-hal/busio/SPI.c:176
+msgid "Baud rate too high for this SPI peripheral"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:48
+#, c-format
+msgid "error = 0x%08lX"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:86
+msgid "Invalid buffer size"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:90
+msgid "Odd parity is not supported"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:322 ports/nrf/common-hal/busio/UART.c:326
+#: ports/nrf/common-hal/busio/UART.c:331 ports/nrf/common-hal/busio/UART.c:336
+#: ports/nrf/common-hal/busio/UART.c:342 ports/nrf/common-hal/busio/UART.c:347
+#: ports/nrf/common-hal/busio/UART.c:352 ports/nrf/common-hal/busio/UART.c:356
+#: ports/nrf/common-hal/busio/UART.c:364
+msgid "busio.UART not available"
 msgstr ""
 
 #: ports/nrf/common-hal/microcontroller/Processor.c:49
diff --git a/locale/es.po b/locale/es.po
index 87edf4ac46..2ac904943c 100644
--- a/locale/es.po
+++ b/locale/es.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-10-01 18:44-0400\n"
+"POT-Creation-Date: 2018-10-03 23:15+0700\n"
 "PO-Revision-Date: 2018-08-24 22:56-0500\n"
 "Last-Translator: \n"
 "Language-Team: \n"
@@ -393,10 +393,12 @@ msgid "bytes > 8 bits not supported"
 msgstr "bytes > 8 bits no son soportados"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:72
+#: ports/nrf/common-hal/busio/UART.c:82
 msgid "tx and rx cannot both be None"
 msgstr "tx y rx no pueden ser ambos None"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:145
+#: ports/nrf/common-hal/busio/UART.c:115
 msgid "Failed to allocate RX buffer"
 msgstr "Fallo la asignación del buffer RX"
 
@@ -405,10 +407,12 @@ msgid "Could not initialize UART"
 msgstr "No se pudo inicializar la UART"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:240
+#: ports/nrf/common-hal/busio/UART.c:149
 msgid "No RX pin"
 msgstr "Sin pin RX"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:294
+#: ports/nrf/common-hal/busio/UART.c:195
 msgid "No TX pin"
 msgstr "Sin pin TX"
 
@@ -715,12 +719,31 @@ msgstr "Todos los timers están siendo utilizados"
 msgid "All SPI peripherals are in use"
 msgstr "Todos los timers están siendo utilizados"
 
-#: ports/nrf/common-hal/busio/UART.c:43 ports/nrf/common-hal/busio/UART.c:47
-#: ports/nrf/common-hal/busio/UART.c:51 ports/nrf/common-hal/busio/UART.c:60
-#: ports/nrf/common-hal/busio/UART.c:66 ports/nrf/common-hal/busio/UART.c:71
-#: ports/nrf/common-hal/busio/UART.c:76 ports/nrf/common-hal/busio/UART.c:81
-#: ports/nrf/common-hal/busio/UART.c:86 ports/nrf/common-hal/busio/UART.c:90
-msgid "busio.UART not yet implemented"
+#: ports/nrf/common-hal/busio/SPI.c:176
+msgid "Baud rate too high for this SPI peripheral"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:48
+#, c-format
+msgid "error = 0x%08lX"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:86
+#, fuzzy
+msgid "Invalid buffer size"
+msgstr "index dupterm inválido"
+
+#: ports/nrf/common-hal/busio/UART.c:90
+#, fuzzy
+msgid "Odd parity is not supported"
+msgstr "bytes > 8 bits no son soportados"
+
+#: ports/nrf/common-hal/busio/UART.c:322 ports/nrf/common-hal/busio/UART.c:326
+#: ports/nrf/common-hal/busio/UART.c:331 ports/nrf/common-hal/busio/UART.c:336
+#: ports/nrf/common-hal/busio/UART.c:342 ports/nrf/common-hal/busio/UART.c:347
+#: ports/nrf/common-hal/busio/UART.c:352 ports/nrf/common-hal/busio/UART.c:356
+#: ports/nrf/common-hal/busio/UART.c:364
+msgid "busio.UART not available"
 msgstr ""
 
 #: ports/nrf/common-hal/microcontroller/Processor.c:49
diff --git a/locale/fil.po b/locale/fil.po
index d0ee493524..7c8c4fdfe2 100644
--- a/locale/fil.po
+++ b/locale/fil.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-10-01 18:44-0400\n"
+"POT-Creation-Date: 2018-10-03 23:15+0700\n"
 "PO-Revision-Date: 2018-08-30 23:04-0700\n"
 "Last-Translator: Timothy <me@timothygarcia.ca>\n"
 "Language-Team: fil\n"
@@ -390,10 +390,12 @@ msgid "bytes > 8 bits not supported"
 msgstr "hindi sinusuportahan ang bytes > 8 bits"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:72
+#: ports/nrf/common-hal/busio/UART.c:82
 msgid "tx and rx cannot both be None"
 msgstr "tx at rx hindi pwedeng parehas na None"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:145
+#: ports/nrf/common-hal/busio/UART.c:115
 msgid "Failed to allocate RX buffer"
 msgstr "Nabigong ilaan ang RX buffer"
 
@@ -402,10 +404,12 @@ msgid "Could not initialize UART"
 msgstr "Hindi ma-initialize ang UART"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:240
+#: ports/nrf/common-hal/busio/UART.c:149
 msgid "No RX pin"
 msgstr "Walang RX pin"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:294
+#: ports/nrf/common-hal/busio/UART.c:195
 msgid "No TX pin"
 msgstr "Walang TX pin"
 
@@ -715,13 +719,33 @@ msgstr "Lahat ng timer ginagamit"
 msgid "All SPI peripherals are in use"
 msgstr "Lahat ng timer ginagamit"
 
-#: ports/nrf/common-hal/busio/UART.c:43 ports/nrf/common-hal/busio/UART.c:47
-#: ports/nrf/common-hal/busio/UART.c:51 ports/nrf/common-hal/busio/UART.c:60
-#: ports/nrf/common-hal/busio/UART.c:66 ports/nrf/common-hal/busio/UART.c:71
-#: ports/nrf/common-hal/busio/UART.c:76 ports/nrf/common-hal/busio/UART.c:81
-#: ports/nrf/common-hal/busio/UART.c:86 ports/nrf/common-hal/busio/UART.c:90
-msgid "busio.UART not yet implemented"
-msgstr "hindi pa implemented ang busio.UART"
+#: ports/nrf/common-hal/busio/SPI.c:176
+msgid "Baud rate too high for this SPI peripheral"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:48
+#, c-format
+msgid "error = 0x%08lX"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:86
+#, fuzzy
+msgid "Invalid buffer size"
+msgstr "mali ang buffer length"
+
+#: ports/nrf/common-hal/busio/UART.c:90
+#, fuzzy
+msgid "Odd parity is not supported"
+msgstr "hindi sinusuportahan ang bytes > 8 bits"
+
+#: ports/nrf/common-hal/busio/UART.c:322 ports/nrf/common-hal/busio/UART.c:326
+#: ports/nrf/common-hal/busio/UART.c:331 ports/nrf/common-hal/busio/UART.c:336
+#: ports/nrf/common-hal/busio/UART.c:342 ports/nrf/common-hal/busio/UART.c:347
+#: ports/nrf/common-hal/busio/UART.c:352 ports/nrf/common-hal/busio/UART.c:356
+#: ports/nrf/common-hal/busio/UART.c:364
+#, fuzzy
+msgid "busio.UART not available"
+msgstr ""
 
 #: ports/nrf/common-hal/microcontroller/Processor.c:49
 #, c-format
diff --git a/locale/fr.po b/locale/fr.po
index 9d07866031..04d7a06656 100644
--- a/locale/fr.po
+++ b/locale/fr.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: 0.1\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-10-01 18:52-0400\n"
+"POT-Creation-Date: 2018-10-03 23:15+0700\n"
 "PO-Revision-Date: 2018-08-14 11:01+0200\n"
 "Last-Translator: Pierrick Couturier <arofarn@arofarn.info>\n"
 "Language-Team: fr\n"
@@ -385,10 +385,12 @@ msgid "bytes > 8 bits not supported"
 msgstr "octets > 8 bits non supporté"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:72
+#: ports/nrf/common-hal/busio/UART.c:82
 msgid "tx and rx cannot both be None"
 msgstr "TX et RX ne peuvent être None tous les deux"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:145
+#: ports/nrf/common-hal/busio/UART.c:115
 msgid "Failed to allocate RX buffer"
 msgstr "Echec de l'allocation du tampon RX"
 
@@ -397,10 +399,12 @@ msgid "Could not initialize UART"
 msgstr "L'UART n'a pu être initialisé"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:240
+#: ports/nrf/common-hal/busio/UART.c:149
 msgid "No RX pin"
 msgstr "Pas de broche RX"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:294
+#: ports/nrf/common-hal/busio/UART.c:195
 msgid "No TX pin"
 msgstr "Pas de broche TX"
 
@@ -711,13 +715,33 @@ msgstr "Tous les timers sont utilisés"
 msgid "All SPI peripherals are in use"
 msgstr "Tous les timers sont utilisés"
 
-#: ports/nrf/common-hal/busio/UART.c:43 ports/nrf/common-hal/busio/UART.c:47
-#: ports/nrf/common-hal/busio/UART.c:51 ports/nrf/common-hal/busio/UART.c:60
-#: ports/nrf/common-hal/busio/UART.c:66 ports/nrf/common-hal/busio/UART.c:71
-#: ports/nrf/common-hal/busio/UART.c:76 ports/nrf/common-hal/busio/UART.c:81
-#: ports/nrf/common-hal/busio/UART.c:86 ports/nrf/common-hal/busio/UART.c:90
-msgid "busio.UART not yet implemented"
-msgstr "busio.UART pas encore implémenté"
+#: ports/nrf/common-hal/busio/SPI.c:176
+msgid "Baud rate too high for this SPI peripheral"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:48
+#, c-format
+msgid "error = 0x%08lX"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:86
+#, fuzzy
+msgid "Invalid buffer size"
+msgstr "longueur de tampon invalide"
+
+#: ports/nrf/common-hal/busio/UART.c:90
+#, fuzzy
+msgid "Odd parity is not supported"
+msgstr "octets > 8 bits non supporté"
+
+#: ports/nrf/common-hal/busio/UART.c:322 ports/nrf/common-hal/busio/UART.c:326
+#: ports/nrf/common-hal/busio/UART.c:331 ports/nrf/common-hal/busio/UART.c:336
+#: ports/nrf/common-hal/busio/UART.c:342 ports/nrf/common-hal/busio/UART.c:347
+#: ports/nrf/common-hal/busio/UART.c:352 ports/nrf/common-hal/busio/UART.c:356
+#: ports/nrf/common-hal/busio/UART.c:364
+#, fuzzy
+msgid "busio.UART not available"
+msgstr "busio.UART n'est pas disponible"
 
 #: ports/nrf/common-hal/microcontroller/Processor.c:49
 #, c-format
diff --git a/locale/pt_BR.po b/locale/pt_BR.po
index 723c9bc8ec..d6b283c9fe 100644
--- a/locale/pt_BR.po
+++ b/locale/pt_BR.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-10-02 01:19-0300\n"
+"POT-Creation-Date: 2018-10-03 23:15+0700\n"
 "PO-Revision-Date: 2018-10-02 21:14-0000\n"
 "Last-Translator: \n"
 "Language-Team: \n"
@@ -361,7 +361,7 @@ msgstr "Não há pinos suficientes disponíveis"
 #: ports/atmel-samd/common-hal/busio/SPI.c:132
 #: ports/atmel-samd/common-hal/busio/UART.c:119
 #: ports/atmel-samd/common-hal/i2cslave/I2CSlave.c:45
-#: ports/nrf/common-hal/busio/I2C.c:77
+#: ports/nrf/common-hal/busio/I2C.c:81
 msgid "Invalid pins"
 msgstr "Pinos inválidos"
 
@@ -378,10 +378,12 @@ msgid "bytes > 8 bits not supported"
 msgstr "bytes > 8 bits não suportado"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:72
+#: ports/nrf/common-hal/busio/UART.c:82
 msgid "tx and rx cannot both be None"
 msgstr "TX e RX não podem ser ambos"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:145
+#: ports/nrf/common-hal/busio/UART.c:115
 msgid "Failed to allocate RX buffer"
 msgstr "Falha ao alocar buffer RX"
 
@@ -390,10 +392,12 @@ msgid "Could not initialize UART"
 msgstr "Não foi possível inicializar o UART"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:240
+#: ports/nrf/common-hal/busio/UART.c:149
 msgid "No RX pin"
 msgstr "Nenhum pino RX"
 
 #: ports/atmel-samd/common-hal/busio/UART.c:294
+#: ports/nrf/common-hal/busio/UART.c:195
 msgid "No TX pin"
 msgstr "Nenhum pino TX"
 
@@ -690,24 +694,39 @@ msgstr ""
 msgid "AnalogOut functionality not supported"
 msgstr ""
 
-#: ports/nrf/common-hal/busio/I2C.c:91
+#: ports/nrf/common-hal/busio/I2C.c:95
 msgid "All I2C peripherals are in use"
 msgstr ""
 
-#: ports/nrf/common-hal/busio/SPI.c:109
+#: ports/nrf/common-hal/busio/SPI.c:115
 msgid "All SPI peripherals are in use"
 msgstr ""
 
-#: ports/nrf/common-hal/busio/SPI.c:170
+#: ports/nrf/common-hal/busio/SPI.c:176
 msgid "Baud rate too high for this SPI peripheral"
 msgstr ""
 
-#: ports/nrf/common-hal/busio/UART.c:43 ports/nrf/common-hal/busio/UART.c:47
-#: ports/nrf/common-hal/busio/UART.c:51 ports/nrf/common-hal/busio/UART.c:60
-#: ports/nrf/common-hal/busio/UART.c:66 ports/nrf/common-hal/busio/UART.c:71
-#: ports/nrf/common-hal/busio/UART.c:76 ports/nrf/common-hal/busio/UART.c:81
-#: ports/nrf/common-hal/busio/UART.c:86 ports/nrf/common-hal/busio/UART.c:90
-msgid "busio.UART not yet implemented"
+#: ports/nrf/common-hal/busio/UART.c:48
+#, c-format
+msgid "error = 0x%08lX"
+msgstr ""
+
+#: ports/nrf/common-hal/busio/UART.c:86
+#, fuzzy
+msgid "Invalid buffer size"
+msgstr "Arquivo inválido"
+
+#: ports/nrf/common-hal/busio/UART.c:90
+#, fuzzy
+msgid "Odd parity is not supported"
+msgstr "I2C operação não suportada"
+
+#: ports/nrf/common-hal/busio/UART.c:322 ports/nrf/common-hal/busio/UART.c:326
+#: ports/nrf/common-hal/busio/UART.c:331 ports/nrf/common-hal/busio/UART.c:336
+#: ports/nrf/common-hal/busio/UART.c:342 ports/nrf/common-hal/busio/UART.c:347
+#: ports/nrf/common-hal/busio/UART.c:352 ports/nrf/common-hal/busio/UART.c:356
+#: ports/nrf/common-hal/busio/UART.c:364
+msgid "busio.UART not available"
 msgstr ""
 
 #: ports/nrf/common-hal/microcontroller/Processor.c:49
@@ -2254,7 +2273,8 @@ msgstr "Limite deve estar no alcance de 0-65536"
 #: shared-bindings/util.c:38
 msgid ""
 "Object has been deinitialized and can no longer be used. Create a new object."
-msgstr "Objeto foi desinicializado e não pode ser mais usaado. Crie um novo objeto."
+msgstr ""
+"Objeto foi desinicializado e não pode ser mais usaado. Crie um novo objeto."
 
 #: shared-module/audioio/WaveFile.c:61
 msgid "Invalid wave file"
diff --git a/ports/nrf/Makefile b/ports/nrf/Makefile
index 0e9d224be7..93ca783760 100755
--- a/ports/nrf/Makefile
+++ b/ports/nrf/Makefile
@@ -91,7 +91,7 @@ SRC_NRFX = $(addprefix nrfx/,\
 	drivers/src/nrfx_power.c \
 	drivers/src/nrfx_spim.c \
 	drivers/src/nrfx_twim.c \
-	drivers/src/nrfx_uart.c \
+	drivers/src/nrfx_uarte.c \
 	)
 
 SRC_C += \
@@ -100,6 +100,7 @@ SRC_C += \
 	internal_flash.c \
 	mphalport.c \
 	tick.c \
+	board_busses.c \
 	boards/$(BOARD)/board.c \
 	boards/$(BOARD)/pins.c \
 	device/$(MCU_VARIANT)/startup_$(MCU_SUB_VARIANT).c \
diff --git a/ports/nrf/boards/feather_nrf52832/mpconfigboard.h b/ports/nrf/boards/feather_nrf52832/mpconfigboard.h
index 0da1abfc47..e751ec182e 100644
--- a/ports/nrf/boards/feather_nrf52832/mpconfigboard.h
+++ b/ports/nrf/boards/feather_nrf52832/mpconfigboard.h
@@ -30,7 +30,6 @@
 
 #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              (32 * 1024)
 #define CIRCUITPY_AUTORELOAD_DELAY_MS 500
diff --git a/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h b/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h
index 81818741d1..bd6d4b2449 100644
--- a/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h
+++ b/ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h
@@ -67,5 +67,5 @@
 #define DEFAULT_SPI_BUS_MOSI        (&pin_P0_23)
 #define DEFAULT_SPI_BUS_MISO        (&pin_P0_22)
 
-#define DEFAULT_UART_BUS_RX         (&pin_P1_0)
+#define DEFAULT_UART_BUS_RX         (&pin_P1_00)
 #define DEFAULT_UART_BUS_TX         (&pin_P0_24)
diff --git a/ports/nrf/boards/pca10056/mpconfigboard.h b/ports/nrf/boards/pca10056/mpconfigboard.h
index de4545d620..00a73005c5 100644
--- a/ports/nrf/boards/pca10056/mpconfigboard.h
+++ b/ports/nrf/boards/pca10056/mpconfigboard.h
@@ -28,17 +28,9 @@
 #define MICROPY_HW_MCU_NAME         "nRF52840"
 #define MICROPY_PY_SYS_PLATFORM     "nRF52840-DK"
 
-// See legend on bottom of board
-#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
 
-// Temp (could be removed) 0: usb cdc (default), 1 : hwuart (jlink)
-#define CFG_HWUART_FOR_SERIAL        0
-
 #define DEFAULT_I2C_BUS_SCL         (&pin_P0_27)
 #define DEFAULT_I2C_BUS_SDA         (&pin_P0_26)
 
diff --git a/ports/nrf/boards/pca10056/pins.c b/ports/nrf/boards/pca10056/pins.c
index 1c208f89b5..a57c9d1c95 100644
--- a/ports/nrf/boards/pca10056/pins.c
+++ b/ports/nrf/boards/pca10056/pins.c
@@ -124,6 +124,8 @@ STATIC const mp_rom_map_elem_t board_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_P1_15), MP_ROM_PTR(&pin_P1_15) },
     { MP_ROM_QSTR(MP_QSTR_D13), MP_ROM_PTR(&pin_P1_15) },
     { MP_ROM_QSTR(MP_QSTR_SCK), MP_ROM_PTR(&pin_P1_15) },
+
+    { MP_ROM_QSTR(MP_QSTR_UART), MP_ROM_PTR(&board_uart_obj) },
 };
 
 MP_DEFINE_CONST_DICT(board_module_globals, board_module_globals_table);
diff --git a/ports/nrf/common-hal/busio/UART.c b/ports/nrf/common-hal/busio/UART.c
index 06a348b767..b2dbb56a1f 100644
--- a/ports/nrf/common-hal/busio/UART.c
+++ b/ports/nrf/common-hal/busio/UART.c
@@ -35,58 +35,333 @@
 #include "supervisor/shared/translate.h"
 
 #include "tick.h"
+#include "nrfx_uarte.h"
+#include <string.h>
 
-void common_hal_busio_uart_construct(busio_uart_obj_t *self,
-        const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx, uint32_t baudrate,
-        uint8_t bits, uart_parity_t parity, uint8_t stop, uint32_t timeout,
-        uint8_t receiver_buffer_size) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
+#ifdef NRF52840_XXAA
+
+// expression to examine, and return value in case of failing
+#define _VERIFY_ERR(_exp) \
+    do {\
+      uint32_t _err = (_exp);\
+      if (NRFX_SUCCESS != _err ) {\
+        mp_raise_msg_varg(&mp_type_RuntimeError, translate("error = 0x%08lX"), _err);\
+      }\
+    }while(0)
+
+static uint32_t get_nrf_baud (uint32_t baudrate);
+
+static void uart_callback_irq (const nrfx_uarte_event_t * event, void * context) {
+    busio_uart_obj_t* self = (busio_uart_obj_t*) context;
+
+    switch ( event->type ) {
+        case NRFX_UARTE_EVT_RX_DONE:
+            self->rx_count = event->data.rxtx.bytes;
+        break;
+
+        case NRFX_UARTE_EVT_TX_DONE:
+        break;
+
+        case NRFX_UARTE_EVT_ERROR:
+            if ( self->rx_count == -1 ) {
+                self->rx_count = 0;
+            }
+        break;
+
+        default:
+        break;
+    }
+}
+
+
+void common_hal_busio_uart_construct (busio_uart_obj_t *self,
+                                      const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx, uint32_t baudrate,
+                                      uint8_t bits, uart_parity_t parity, uint8_t stop, uint32_t timeout,
+                                      uint8_t receiver_buffer_size) {
+    if ( (tx == mp_const_none) && (rx == mp_const_none) ) {
+        mp_raise_ValueError(translate("tx and rx cannot both be None"));
+    }
+
+    if ( receiver_buffer_size == 0 ) {
+        mp_raise_ValueError(translate("Invalid buffer size"));
+    }
+
+    if ( parity == PARITY_ODD ) {
+        mp_raise_ValueError(translate("Odd parity is not supported"));
+    }
+
+    nrfx_uarte_config_t config = {
+        .pseltxd = (tx == mp_const_none) ? NRF_UARTE_PSEL_DISCONNECTED : tx->number,
+        .pselrxd = (rx == mp_const_none) ? NRF_UARTE_PSEL_DISCONNECTED : rx->number,
+        .pselcts = NRF_UARTE_PSEL_DISCONNECTED,
+        .pselrts = NRF_UARTE_PSEL_DISCONNECTED,
+        .p_context = self,
+        .hwfc = NRF_UARTE_HWFC_DISABLED,
+        .parity = (parity == PARITY_NONE) ? NRF_UARTE_PARITY_EXCLUDED : NRF_UARTE_PARITY_INCLUDED,
+        .baudrate = get_nrf_baud(baudrate),
+        .interrupt_priority = 7
+    };
+
+    // support only 1 instance for now
+    self->uarte = (nrfx_uarte_t ) NRFX_UARTE_INSTANCE(0);
+    nrfx_uarte_uninit(&self->uarte);
+    _VERIFY_ERR(nrfx_uarte_init(&self->uarte, &config, uart_callback_irq));
+
+    // Init buffer for rx
+    if ( rx != mp_const_none ) {
+        self->buffer = (uint8_t *) gc_alloc(receiver_buffer_size, false, false);
+        if ( !self->buffer ) {
+            nrfx_uarte_uninit(&self->uarte);
+            mp_raise_msg(&mp_type_MemoryError, translate("Failed to allocate RX buffer"));
+        }
+        self->bufsize = receiver_buffer_size;
+
+        claim_pin(rx);
+    }
+
+    if ( tx != mp_const_none ) {
+        claim_pin(tx);
+    }
+
+    self->baudrate = baudrate;
+    self->timeout_ms = timeout;
+
+    // queue 1-byte transfer for rx_characters_available()
+    self->rx_count = -1;
+    _VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, 1));
 }
 
 bool common_hal_busio_uart_deinited(busio_uart_obj_t *self) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
+    return (nrf_uarte_rx_pin_get(self->uarte.p_reg) == NRF_UARTE_PSEL_DISCONNECTED) &&
+           (nrf_uarte_tx_pin_get(self->uarte.p_reg) == NRF_UARTE_PSEL_DISCONNECTED);
 }
 
 void common_hal_busio_uart_deinit(busio_uart_obj_t *self) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
-    if (common_hal_busio_uart_deinited(self)) {
-        return;
+    if ( !common_hal_busio_uart_deinited(self) ) {
+        nrfx_uarte_uninit(&self->uarte);
+        gc_free(self->buffer);
     }
-    // Do deinit;
 }
 
 // Read characters.
 size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t len, int *errcode) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
-    return 0;
+    if ( nrf_uarte_rx_pin_get(self->uarte.p_reg) == NRF_UARTE_PSEL_DISCONNECTED ) {
+        mp_raise_ValueError(translate("No RX pin"));
+    }
+
+    size_t remain = len;
+    uint64_t start_ticks = ticks_ms;
+
+    while ( 1 ) {
+        // Wait for on-going transfer to complete
+        while ( (self->rx_count == -1) && (ticks_ms - start_ticks < self->timeout_ms) ) {
+#ifdef MICROPY_VM_HOOK_LOOP
+            MICROPY_VM_HOOK_LOOP
+#endif
+        }
+
+        // copy received data
+        if ( self->rx_count > 0 ) {
+            memcpy(data, self->buffer, self->rx_count);
+            data += self->rx_count;
+            remain -= self->rx_count;
+
+            self->rx_count = 0;
+        }
+
+        // exit if complete or time up
+        if ( !remain || !(ticks_ms - start_ticks < self->timeout_ms) ) {
+            break;
+        }
+
+        // prepare next receiving
+        const size_t cnt = MIN(self->bufsize, remain);
+        self->rx_count = -1;
+        _VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, cnt));
+    }
+    
+    // queue 1-byte transfer for rx_characters_available()
+    if ( self->rx_count == 0 ) {
+        self->rx_count = -1;
+        _VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, 1));
+    }
+
+    return len - remain;
 }
 
 // Write characters.
-size_t common_hal_busio_uart_write(busio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
-    return 0;
+size_t common_hal_busio_uart_write (busio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
+    if ( nrf_uarte_tx_pin_get(self->uarte.p_reg) == NRF_UARTE_PSEL_DISCONNECTED ) {
+        mp_raise_ValueError(translate("No TX pin"));
+    }
+
+    if ( len == 0 ) return 0;
+
+    uint64_t start_ticks = ticks_ms;
+
+    // Wait for on-going transfer to complete
+    while ( nrfx_uarte_tx_in_progress(&self->uarte) && (ticks_ms - start_ticks < self->timeout_ms) ) {
+#ifdef MICROPY_VM_HOOK_LOOP
+        MICROPY_VM_HOOK_LOOP
+#endif
+    }
+
+    // Time up
+    if ( !(ticks_ms - start_ticks < self->timeout_ms) ) {
+        *errcode = MP_EAGAIN;
+        return MP_STREAM_ERROR;
+    }
+
+    // EasyDMA can only access SRAM
+    uint8_t * tx_buf = (uint8_t*) data;
+    if ( !nrfx_is_in_ram(data) ) {
+        tx_buf = (uint8_t *) gc_alloc(len, false, false);
+        memcpy(tx_buf, data, len);
+    }
+
+    (*errcode) = nrfx_uarte_tx(&self->uarte, tx_buf, len);
+    _VERIFY_ERR(*errcode);
+    (*errcode) = 0;
+
+    while ( nrfx_uarte_tx_in_progress(&self->uarte) && (ticks_ms - start_ticks < self->timeout_ms) ) {
+#ifdef MICROPY_VM_HOOK_LOOP
+        MICROPY_VM_HOOK_LOOP
+#endif
+    }
+
+    if ( !nrfx_is_in_ram(data) ) {
+        gc_free(tx_buf);
+    }
+
+    return len;
 }
 
 uint32_t common_hal_busio_uart_get_baudrate(busio_uart_obj_t *self) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
     return self->baudrate;
 }
 
 void common_hal_busio_uart_set_baudrate(busio_uart_obj_t *self, uint32_t baudrate) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
     self->baudrate = baudrate;
+    nrf_uarte_baudrate_set(self->uarte.p_reg, get_nrf_baud(baudrate));
 }
 
 uint32_t common_hal_busio_uart_rx_characters_available(busio_uart_obj_t *self) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
-    return 0;
+    return (self->rx_count > 0) ? self->rx_count : 0;
 }
 
 void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
+    // Discard received byte, and queue 1-byte transfer for rx_characters_available()
+    if ( self->rx_count > 0 ) {
+        self->rx_count = -1;
+        _VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, 1));
+    }
 }
 
 bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
-    mp_raise_NotImplementedError(translate("busio.UART not yet implemented"));
+    return !nrfx_uarte_tx_in_progress(&self->uarte);
+}
+
+static uint32_t get_nrf_baud (uint32_t baudrate)
+{
+    if ( baudrate <= 1200 ) {
+        return NRF_UARTE_BAUDRATE_1200;
+    }
+    else if ( baudrate <= 2400 ) {
+        return NRF_UARTE_BAUDRATE_2400;
+    }
+    else if ( baudrate <= 4800 ) {
+        return NRF_UARTE_BAUDRATE_4800;
+    }
+    else if ( baudrate <= 9600 ) {
+        return NRF_UARTE_BAUDRATE_9600;
+    }
+    else if ( baudrate <= 14400 ) {
+        return NRF_UARTE_BAUDRATE_14400;
+    }
+    else if ( baudrate <= 19200 ) {
+        return NRF_UARTE_BAUDRATE_19200;
+    }
+    else if ( baudrate <= 28800 ) {
+        return NRF_UARTE_BAUDRATE_28800;
+    }
+    else if ( baudrate <= 38400 ) {
+        return NRF_UARTE_BAUDRATE_38400;
+    }
+    else if ( baudrate <= 57600 ) {
+        return NRF_UARTE_BAUDRATE_57600;
+    }
+    else if ( baudrate <= 76800 ) {
+        return NRF_UARTE_BAUDRATE_76800;
+    }
+    else if ( baudrate <= 115200 ) {
+        return NRF_UARTE_BAUDRATE_115200;
+    }
+    else if ( baudrate <= 230400 ) {
+        return NRF_UARTE_BAUDRATE_230400;
+    }
+    else if ( baudrate <= 250000 ) {
+        return NRF_UARTE_BAUDRATE_250000;
+    }
+    else if ( baudrate <= 460800 ) {
+        return NRF_UARTE_BAUDRATE_460800;
+    }
+    else if ( baudrate <= 921600 ) {
+        return NRF_UARTE_BAUDRATE_921600;
+    }
+    else {
+        return NRF_UARTE_BAUDRATE_1000000;
+    }
+}
+
+#else
+
+void common_hal_busio_uart_construct (busio_uart_obj_t *self,
+                                      const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx, uint32_t baudrate,
+                                      uint8_t bits, uart_parity_t parity, uint8_t stop, uint32_t timeout,
+                                      uint8_t receiver_buffer_size) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+}
+
+bool common_hal_busio_uart_deinited (busio_uart_obj_t *self) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+    return true;
+}
+
+void common_hal_busio_uart_deinit (busio_uart_obj_t *self) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+}
+
+// Read characters.
+size_t common_hal_busio_uart_read (busio_uart_obj_t *self, uint8_t *data, size_t len, int *errcode) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+    return 0;
+}
+
+// Write characters.
+size_t common_hal_busio_uart_write (busio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+    return 0;
+}
+
+uint32_t common_hal_busio_uart_get_baudrate (busio_uart_obj_t *self) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+    return self->baudrate;
+}
+
+void common_hal_busio_uart_set_baudrate (busio_uart_obj_t *self, uint32_t baudrate) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+}
+
+uint32_t common_hal_busio_uart_rx_characters_available (busio_uart_obj_t *self) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
+}
+
+void common_hal_busio_uart_clear_rx_buffer (busio_uart_obj_t *self) {
+
+}
+
+bool common_hal_busio_uart_ready_to_tx (busio_uart_obj_t *self) {
+    mp_raise_NotImplementedError(translate("busio.UART not available"));
     return false;
 }
+#endif
diff --git a/ports/nrf/common-hal/busio/UART.h b/ports/nrf/common-hal/busio/UART.h
index 7c0493e37e..aef377f146 100644
--- a/ports/nrf/common-hal/busio/UART.h
+++ b/ports/nrf/common-hal/busio/UART.h
@@ -28,23 +28,22 @@
 #define MICROPY_INCLUDED_NRF_COMMON_HAL_BUSIO_UART_H
 
 #include "common-hal/microcontroller/Pin.h"
+#include "nrfx_uarte.h"
 
 #include "py/obj.h"
+#include "py/ringbuf.h"
 
 typedef struct {
     mp_obj_base_t base;
-    uint8_t rx_pin;
-    uint8_t tx_pin;
-    uint8_t character_bits;
-    bool rx_error;
+
+    nrfx_uarte_t uarte;
+
     uint32_t baudrate;
     uint32_t timeout_ms;
-    // Index of the oldest received character.
-    uint32_t buffer_start;
-    // Index of the next available spot to store a character.
-    uint32_t buffer_size;
-    uint32_t buffer_length;
+
     uint8_t* buffer;
+    uint32_t bufsize;
+    volatile int32_t rx_count;
 } busio_uart_obj_t;
 
 #endif // MICROPY_INCLUDED_NRF_COMMON_HAL_BUSIO_UART_H
diff --git a/ports/nrf/mphalport.c b/ports/nrf/mphalport.c
index 1e1ebf32e6..27ed57bf38 100644
--- a/ports/nrf/mphalport.c
+++ b/ports/nrf/mphalport.c
@@ -27,36 +27,40 @@
 
 #include <string.h>
 
-#include "mphalport.h"
+#include "py/mphal.h"
 #include "py/mpstate.h"
-
+#include "py/gc.h"
 
 #if (MICROPY_PY_BLE_NUS == 0)
 
-#if !defined( NRF52840_XXAA) || ( defined(CFG_HWUART_FOR_SERIAL) && CFG_HWUART_FOR_SERIAL == 1 )
+#if !defined( NRF52840_XXAA)
 int mp_hal_stdin_rx_chr(void) {
-    uint8_t data = 0;
-
-    while (!nrfx_uart_rx_ready(&serial_instance));
-
-    const nrfx_err_t err = nrfx_uart_rx(&serial_instance, &data, sizeof(data));
-    if (err == NRFX_SUCCESS)
-        NRFX_ASSERT(err);
-
+    uint8_t data;
+    nrfx_uarte_rx(&serial_instance, &data, 1);
     return data;
 }
 
 bool mp_hal_stdin_any(void) {
-    return nrfx_uart_rx_ready(&serial_instance);
+    return nrf_uarte_event_check(serial_instance.p_reg, NRF_UARTE_EVENT_RXDRDY);
 }
 
 void mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
-    if (len == 0)
+    if (len == 0) {
         return;
+    }
 
-    const nrfx_err_t err = nrfx_uart_tx(&serial_instance, (uint8_t*)str, len);
-    if (err == NRFX_SUCCESS)
-        NRFX_ASSERT(err);
+    // EasyDMA can only access SRAM
+    uint8_t * tx_buf = (uint8_t*) str;
+    if ( !nrfx_is_in_ram(str) ) {
+        tx_buf = (uint8_t *) gc_alloc(len, false, false);
+        memcpy(tx_buf, str, len);
+    }
+
+    nrfx_uarte_tx(&serial_instance, tx_buf, len);
+
+    if ( !nrfx_is_in_ram(str) ) {
+        gc_free(tx_buf);
+    }
 }
 
 #else
diff --git a/ports/nrf/mphalport.h b/ports/nrf/mphalport.h
index f283cf38da..a1929a4ace 100644
--- a/ports/nrf/mphalport.h
+++ b/ports/nrf/mphalport.h
@@ -31,21 +31,16 @@
 #include <stdint.h>
 
 #include "lib/utils/interrupt_char.h"
-#include "nrfx_uart.h"
+#include "nrfx_uarte.h"
 #include "py/mpconfig.h"
 
-extern nrfx_uart_t serial_instance;
+extern nrfx_uarte_t serial_instance;
 
 extern volatile uint64_t ticks_ms;
 
-static inline mp_uint_t mp_hal_ticks_ms(void) {
-    return ticks_ms;
-}
-
-int mp_hal_stdin_rx_chr(void);
-void mp_hal_stdout_tx_str(const char *str);
-bool mp_hal_stdin_any(void);
-void mp_hal_delay_ms(mp_uint_t ms);
+#define mp_hal_ticks_ms()       ((mp_uint_t) ticks_ms)
 #define mp_hal_delay_us(us)     NRFX_DELAY_US((uint32_t) (us))
 
+bool mp_hal_stdin_any(void);
+
 #endif
diff --git a/ports/nrf/nrfx b/ports/nrf/nrfx
index 293f553ed9..67710e47c7 160000
--- a/ports/nrf/nrfx
+++ b/ports/nrf/nrfx
@@ -1 +1 @@
-Subproject commit 293f553ed9551c1fdfd05eac48e75bbdeb4e7290
+Subproject commit 67710e47c7313cc56a15748e485079831ee6a3af
diff --git a/ports/nrf/nrfx_config.h b/ports/nrf/nrfx_config.h
index cc4d193277..f217cb0534 100644
--- a/ports/nrf/nrfx_config.h
+++ b/ports/nrf/nrfx_config.h
@@ -45,13 +45,8 @@
 #define NRFX_TWIM_DEFAULT_CONFIG_HOLD_BUS_UNINIT 0
 
 // UART
-#define NRFX_UART_ENABLED 1
-#define NRFX_UART0_ENABLED 1
-
-#define NRFX_UART_DEFAULT_CONFIG_IRQ_PRIORITY 7
-#define NRFX_UART_DEFAULT_CONFIG_HWFC NRF_UART_HWFC_DISABLED
-#define NRFX_UART_DEFAULT_CONFIG_PARITY NRF_UART_PARITY_EXCLUDED
-#define NRFX_UART_DEFAULT_CONFIG_BAUDRATE NRF_UART_BAUDRATE_115200
+#define NRFX_UARTE_ENABLED 1
+#define NRFX_UARTE0_ENABLED 1
 
 // PWM
 #define NRFX_PWM0_ENABLED 1
diff --git a/ports/nrf/supervisor/serial.c b/ports/nrf/supervisor/serial.c
index da7fe07fd3..cfbcc4b31b 100644
--- a/ports/nrf/supervisor/serial.c
+++ b/ports/nrf/supervisor/serial.c
@@ -24,19 +24,19 @@
  * THE SOFTWARE.
  */
 
-#include "mphalport.h"
+#include "py/mphal.h"
 
 #if MICROPY_PY_BLE_NUS
 #include "ble_uart.h"
 #else
 #include "nrf_gpio.h"
+#include "nrfx_uarte.h"
 #endif
 
-#if !defined( NRF52840_XXAA) || ( defined(CFG_HWUART_FOR_SERIAL) && CFG_HWUART_FOR_SERIAL == 1 )
+#if !defined(NRF52840_XXAA)
 
-#define INST_NO 0
-
-nrfx_uart_t serial_instance = NRFX_UART_INSTANCE(INST_NO);
+uint8_t serial_received_char;
+nrfx_uarte_t serial_instance = NRFX_UARTE_INSTANCE(0);
 
 void serial_init(void) {
 #if MICROPY_PY_BLE_NUS
@@ -45,22 +45,27 @@ void serial_init(void) {
         ;
     }
 #else
-    nrfx_uart_config_t config = NRFX_UART_DEFAULT_CONFIG;
-    config.pseltxd = MICROPY_HW_UART_TX;
-    config.pselrxd = MICROPY_HW_UART_RX;
-    config.hwfc = MICROPY_HW_UART_HWFC ? NRF_UART_HWFC_ENABLED : NRF_UART_HWFC_DISABLED;
-#ifdef MICROPY_HW_UART_CTS
-    config.pselcts = MICROPY_HW_UART_CTS;
-#endif
-#ifdef MICROPY_HW_UART_RTS
-    config.pselrts = MICROPY_HW_UART_RTS;
-#endif
+    nrfx_uarte_config_t config = {
+        .pseltxd = MICROPY_HW_UART_TX,
+        .pselrxd = MICROPY_HW_UART_RX,
+        .pselcts = NRF_UARTE_PSEL_DISCONNECTED,
+        .pselrts = NRF_UARTE_PSEL_DISCONNECTED,
+        .p_context = NULL,
+        .hwfc = NRF_UARTE_HWFC_DISABLED,
+        .parity = NRF_UARTE_PARITY_EXCLUDED,
+        .baudrate = NRF_UARTE_BAUDRATE_115200,
+        .interrupt_priority = 7
+    };
 
-    const nrfx_err_t err = nrfx_uart_init(&serial_instance, &config, NULL);
-    if (err == NRFX_SUCCESS)
+    nrfx_uarte_uninit(&serial_instance);
+    const nrfx_err_t err = nrfx_uarte_init(&serial_instance, &config, NULL);    // no callback for blocking mode
+
+    if (err != NRFX_SUCCESS) {
         NRFX_ASSERT(err);
+    }
 
-    nrfx_uart_rx_enable(&serial_instance);
+    // enabled receiving
+    nrf_uarte_task_trigger(serial_instance.p_reg, NRF_UARTE_TASK_STARTRX);
 #endif
 }