diff --git a/locale/ID.po b/locale/ID.po
index 182dd2679d..01f461392f 100644
--- a/locale/ID.po
+++ b/locale/ID.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\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"
@@ -462,6 +462,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr ""
@@ -1183,6 +1187,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1192,6 +1200,11 @@ msgstr ""
 msgid "RTC is not supported on this board"
 msgstr ""
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1255,6 +1268,14 @@ msgstr "Nilai sampel terlalu tinggi. Nilai harus kurang dari %d"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index e067213560..354dbc4ba4 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: 2020-02-12 11:31-0800\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\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"
@@ -452,6 +452,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr ""
@@ -1169,6 +1173,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1178,6 +1186,11 @@ msgstr ""
 msgid "RTC is not supported on this board"
 msgstr ""
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1239,6 +1252,14 @@ msgstr ""
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/de_DE.po b/locale/de_DE.po
index a5bb053abd..056f56d749 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: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2018-07-27 11:55-0700\n"
 "Last-Translator: Pascal Deneaux\n"
 "Language-Team: Sebastian Plamauer, Pascal Deneaux\n"
@@ -456,6 +456,10 @@ msgstr "Reset zum bootloader nicht möglich da bootloader nicht vorhanden"
 msgid "Cannot set value when direction is input."
 msgstr "Der Wert kann nicht gesetzt werden, wenn die Richtung input ist."
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr ""
@@ -1186,6 +1190,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1195,6 +1203,11 @@ msgstr "Die RTC-Kalibrierung wird auf diesem Board nicht unterstützt"
 msgid "RTC is not supported on this board"
 msgstr "Eine RTC wird auf diesem Board nicht unterstützt"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1256,6 +1269,14 @@ msgstr "Abtastrate zu hoch. Wert muss unter %d liegen"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/en_US.po b/locale/en_US.po
index 5485810a31..58c798ce4b 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: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2018-07-27 11:55-0700\n"
 "Last-Translator: \n"
 "Language-Team: \n"
@@ -452,6 +452,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr ""
@@ -1169,6 +1173,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1178,6 +1186,11 @@ msgstr ""
 msgid "RTC is not supported on this board"
 msgstr ""
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1239,6 +1252,14 @@ msgstr ""
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/en_x_pirate.po b/locale/en_x_pirate.po
index 517d067dad..e2ee9c887d 100644
--- a/locale/en_x_pirate.po
+++ b/locale/en_x_pirate.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2018-07-27 11:55-0700\n"
 "Last-Translator: \n"
 "Language-Team: @sommersoft, @MrCertainly\n"
@@ -456,6 +456,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr ""
@@ -1173,6 +1177,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1182,6 +1190,11 @@ msgstr ""
 msgid "RTC is not supported on this board"
 msgstr ""
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1243,6 +1256,14 @@ msgstr ""
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/es.po b/locale/es.po
index 76f0799249..8d445a469a 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: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2018-08-24 22:56-0500\n"
 "Last-Translator: \n"
 "Language-Team: \n"
@@ -458,6 +458,10 @@ msgstr "No se puede reiniciar a bootloader porque no hay bootloader presente."
 msgid "Cannot set value when direction is input."
 msgstr "No se puede asignar un valor cuando la dirección es input."
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr "Cannot subclass slice"
@@ -1185,6 +1189,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1194,6 +1202,11 @@ msgstr "Calibración de RTC no es soportada en esta placa"
 msgid "RTC is not supported on this board"
 msgstr "RTC no soportado en esta placa"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1256,6 +1269,14 @@ msgstr "Frecuencia de muestreo demasiado alta. Debe ser menor a %d"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/fil.po b/locale/fil.po
index 187c31b538..b8b61d723b 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: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2018-12-20 22:15-0800\n"
 "Last-Translator: Timothy <me@timothygarcia.ca>\n"
 "Language-Team: fil\n"
@@ -460,6 +460,10 @@ msgstr "Hindi ma-reset sa bootloader dahil walang bootloader."
 msgid "Cannot set value when direction is input."
 msgstr "Hindi ma i-set ang value kapag ang direksyon ay input."
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr "Hindi magawa ang sublcass slice"
@@ -1191,6 +1195,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1200,6 +1208,11 @@ msgstr "RTC calibration ay hindi supportado ng board na ito"
 msgid "RTC is not supported on this board"
 msgstr "Hindi supportado ang RTC sa board na ito"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1262,6 +1275,14 @@ msgstr "Sample rate ay masyadong mataas. Ito ay dapat hindi hiigit sa %d"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/fr.po b/locale/fr.po
index 8b66e5c0d6..625b4e91aa 100644
--- a/locale/fr.po
+++ b/locale/fr.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: 0.1\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2019-04-14 20:05+0100\n"
 "Last-Translator: Pierrick Couturier <arofarn@arofarn.info>\n"
 "Language-Team: fr\n"
@@ -465,6 +465,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr "Impossible d'affecter une valeur quand la direction est 'input'."
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr "On ne peut faire de sous-classes de tranches"
@@ -1204,6 +1208,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1213,6 +1221,11 @@ msgstr "étalonnage de la RTC non supportée sur cette carte"
 msgid "RTC is not supported on this board"
 msgstr "RTC non supportée sur cette carte"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1276,6 +1289,14 @@ msgstr "Taux d'échantillonage trop élevé. Doit être inf. à %d"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/it_IT.po b/locale/it_IT.po
index 3671a6ec23..93af9bdb86 100644
--- a/locale/it_IT.po
+++ b/locale/it_IT.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2018-10-02 16:27+0200\n"
 "Last-Translator: Enrico Paganin <enrico.paganin@mail.com>\n"
 "Language-Team: \n"
@@ -461,6 +461,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr "non si può impostare un valore quando direzione è input"
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr "Impossibile subclasare slice"
@@ -1200,6 +1204,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1209,6 +1217,11 @@ msgstr "calibrazione RTC non supportata su questa scheda"
 msgid "RTC is not supported on this board"
 msgstr "RTC non supportato su questa scheda"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1273,6 +1286,14 @@ msgstr ""
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/ko.po b/locale/ko.po
index f1f550775d..04ab849d43 100644
--- a/locale/ko.po
+++ b/locale/ko.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2019-05-06 14:22-0700\n"
 "Last-Translator: \n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -456,6 +456,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr ""
@@ -1173,6 +1177,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1182,6 +1190,11 @@ msgstr ""
 msgid "RTC is not supported on this board"
 msgstr ""
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1243,6 +1256,14 @@ msgstr ""
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/pl.po b/locale/pl.po
index ee95b2e7d1..d766191822 100644
--- a/locale/pl.po
+++ b/locale/pl.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2019-03-19 18:37-0700\n"
 "Last-Translator: Radomir Dopieralski <circuitpython@sheep.art.pl>\n"
 "Language-Team: pl\n"
@@ -455,6 +455,10 @@ msgstr "Nie można zrestartować -- nie ma bootloadera."
 msgid "Cannot set value when direction is input."
 msgstr "Nie można ustawić wartości w trybie wejścia"
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr "Nie można dziedziczyć ze slice"
@@ -1174,6 +1178,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1183,6 +1191,11 @@ msgstr "Brak obsługi kalibracji RTC"
 msgid "RTC is not supported on this board"
 msgstr "Brak obsługi RTC"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1244,6 +1257,14 @@ msgstr "Zbyt wysoka częstotliwość próbkowania. Musi być mniejsza niż %d"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/pt_BR.po b/locale/pt_BR.po
index b94b14fcd5..b948003a18 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: 2020-02-10 11:46-0500\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2018-10-02 21:14-0000\n"
 "Last-Translator: \n"
 "Language-Team: \n"
@@ -457,6 +457,10 @@ msgstr ""
 msgid "Cannot set value when direction is input."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr ""
@@ -1185,6 +1189,10 @@ msgstr ""
 msgid "RNG Init Error"
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1194,6 +1202,11 @@ msgstr "A calibração RTC não é suportada nesta placa"
 msgid "RTC is not supported on this board"
 msgstr "O RTC não é suportado nesta placa"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr ""
@@ -1256,6 +1269,14 @@ msgstr "Taxa de amostragem muito alta. Deve ser menor que %d"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr ""
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/locale/zh_Latn_pinyin.po b/locale/zh_Latn_pinyin.po
index dcb78828c6..9a9473436f 100644
--- a/locale/zh_Latn_pinyin.po
+++ b/locale/zh_Latn_pinyin.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: circuitpython-cn\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2020-02-12 11:31-0800\n"
+"POT-Creation-Date: 2020-02-19 08:44+0000\n"
 "PO-Revision-Date: 2019-04-13 10:10-0700\n"
 "Last-Translator: hexthat\n"
 "Language-Team: Chinese Hanyu Pinyin\n"
@@ -461,6 +461,10 @@ msgstr "Wúfǎ chóng zhì wèi bootloader, yīnwèi méiyǒu bootloader cúnzà
 msgid "Cannot set value when direction is input."
 msgstr "Dāng fāngxiàng xiàng nèi shí, bùnéng shèzhì gāi zhí."
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Cannot specify RTS or CTS in RS485 mode"
+msgstr ""
+
 #: py/objslice.c
 msgid "Cannot subclass slice"
 msgstr "Wúfǎ zi fēnlèi"
@@ -1188,6 +1192,10 @@ msgstr "RNG qǔxiāo chūshǐhuà cuòwù"
 msgid "RNG Init Error"
 msgstr "RNG chūshǐhuà cuòwù"
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "RS485 inversion specified when not in RS485 mode"
+msgstr ""
+
 #: ports/cxd56/common-hal/rtc/RTC.c ports/mimxrt10xx/common-hal/rtc/RTC.c
 #: ports/nrf/common-hal/rtc/RTC.c
 msgid "RTC calibration is not supported on this board"
@@ -1197,6 +1205,11 @@ msgstr "Cǐ bǎn bù zhīchí RTC jiàozhǔn"
 msgid "RTC is not supported on this board"
 msgstr "Cǐ bǎn bù zhīchí RTC"
 
+#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
+#: ports/nrf/common-hal/busio/UART.c ports/stm32f4/common-hal/busio/UART.c
+msgid "RTS/CTS/RS485 Not yet supported on this device"
+msgstr ""
+
 #: ports/stm32f4/common-hal/os/__init__.c
 msgid "Random number generation error"
 msgstr "Suíjī shù shēngchéng cuòwù"
@@ -1258,6 +1271,14 @@ msgstr "Cǎiyàng lǜ tài gāo. Tā bìxū xiǎoyú %d"
 msgid "Scan already in progess. Stop with stop_scan."
 msgstr "Zhèngzài jìn háng sǎomiáo. Shǐyòng stop_scan tíngzhǐ."
 
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected CTS pin not valid"
+msgstr ""
+
+#: ports/mimxrt10xx/common-hal/busio/UART.c
+msgid "Selected RTS pin not valid"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
 msgid "Serializer in use"
diff --git a/ports/atmel-samd/common-hal/busio/UART.c b/ports/atmel-samd/common-hal/busio/UART.c
index 70857de6de..fb9968605f 100644
--- a/ports/atmel-samd/common-hal/busio/UART.c
+++ b/ports/atmel-samd/common-hal/busio/UART.c
@@ -52,9 +52,12 @@ static void usart_async_rxc_callback(const struct usart_async_descriptor *const
 }
 
 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, mp_float_t timeout,
-        uint16_t receiver_buffer_size) {
+    const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
+    const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
+    const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
+    uint32_t baudrate, uint8_t bits, uart_parity_t parity, uint8_t stop,
+    mp_float_t timeout, uint16_t receiver_buffer_size) {
+
     Sercom* sercom = NULL;
     uint8_t sercom_index = 255; // Unset index
     uint32_t rx_pinmux = 0;
@@ -62,6 +65,10 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
     uint32_t tx_pinmux = 0;
     uint8_t tx_pad = 255; // Unset pad
 
+    if ((rts != mp_const_none) || (cts != mp_const_none) || (rs485_dir != mp_const_none) || (rs485_invert)) {
+        mp_raise_ValueError(translate("RTS/CTS/RS485 Not yet supported on this device"));
+    }
+
     if (bits > 8) {
         mp_raise_NotImplementedError(translate("bytes > 8 bits not supported"));
     }
diff --git a/ports/cxd56/common-hal/busio/UART.c b/ports/cxd56/common-hal/busio/UART.c
index 40ae3b7614..3ed9809529 100644
--- a/ports/cxd56/common-hal/busio/UART.c
+++ b/ports/cxd56/common-hal/busio/UART.c
@@ -53,11 +53,17 @@ STATIC busio_uart_dev_t busio_uart_dev[] = {
 };
 
 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, mp_float_t timeout,
-    uint16_t receiver_buffer_size) {
+    const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
+    const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
+    const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
+    uint32_t baudrate, uint8_t bits, uart_parity_t parity, uint8_t stop,
+    mp_float_t timeout, uint16_t receiver_buffer_size) {
     struct termios tio;
 
+    if ((rts != mp_const_none) || (cts != mp_const_none) || (rs485_dir != mp_const_none) || (rs485_invert)) {
+        mp_raise_ValueError(translate("RTS/CTS/RS485 Not yet supported on this device"));
+    }
+    
     if (bits != 8) {
         mp_raise_ValueError(translate("Could not initialize UART"));
     }
diff --git a/ports/mimxrt10xx/boards/imxrt1020_evk/flash_config.c b/ports/mimxrt10xx/boards/imxrt1020_evk/flash_config.c
index b74c0b1514..80a57f17be 100644
--- a/ports/mimxrt10xx/boards/imxrt1020_evk/flash_config.c
+++ b/ports/mimxrt10xx/boards/imxrt1020_evk/flash_config.c
@@ -42,7 +42,11 @@ const flexspi_nor_config_t qspiflash_config = {
         {
             .tag              = FLEXSPI_CFG_BLK_TAG,
             .version          = FLEXSPI_CFG_BLK_VERSION,
-            .readSampleClkSrc = kFlexSPIReadSampleClk_LoopbackFromDqsPad,
+#ifdef BOARD_USING_SECONDARY_QSPI_PINMUX
+            .readSampleClkSrc = kFlexSPIReadSampleClk_LoopbackFromInternally,
+#else
+            .readSampleClkSrc = kFlexSPIReadSampleClk_LoopbackFromDqsPad,            
+#endif
             .csHoldTime       = 1u,
             .csSetupTime      = 2u,
             // Enable DDR mode, Wordaddressable, Safe configuration, Differential clock
diff --git a/ports/mimxrt10xx/common-hal/busio/UART.c b/ports/mimxrt10xx/common-hal/busio/UART.c
index a4819798bc..4fd7afecbc 100644
--- a/ports/mimxrt10xx/common-hal/busio/UART.c
+++ b/ports/mimxrt10xx/common-hal/busio/UART.c
@@ -53,8 +53,8 @@ static void config_periph_pin(const mcu_periph_obj_t *periph) {
     IOMUXC_SetPinConfig(0, 0, 0, 0,
         periph->pin->cfg_reg,
         IOMUXC_SW_PAD_CTL_PAD_HYS(0)
-            | IOMUXC_SW_PAD_CTL_PAD_PUS(0)
-            | IOMUXC_SW_PAD_CTL_PAD_PUE(0)
+            | IOMUXC_SW_PAD_CTL_PAD_PUS(1)
+            | IOMUXC_SW_PAD_CTL_PAD_PUE(1)
             | IOMUXC_SW_PAD_CTL_PAD_PKE(1)
             | IOMUXC_SW_PAD_CTL_PAD_ODE(0)
             | IOMUXC_SW_PAD_CTL_PAD_SPEED(1)
@@ -72,9 +72,11 @@ void LPUART_UserCallback(LPUART_Type *base, lpuart_handle_t *handle, status_t st
 }
 
 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, mp_float_t timeout,
-        uint16_t receiver_buffer_size) {
+        const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
+        const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
+        const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
+        uint32_t baudrate, uint8_t bits, uart_parity_t parity, uint8_t stop,
+        mp_float_t timeout, uint16_t receiver_buffer_size) {
 
     // TODO: Allow none rx or tx
 
@@ -111,12 +113,60 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
 
     if(self->rx_pin == NULL || self->tx_pin == NULL) {
         mp_raise_RuntimeError(translate("Invalid UART pin selection"));
-    } else {
-        self->uart = mcu_uart_banks[self->tx_pin->bank_idx - 1];
     }
 
+    // Filter for sane settings for RS485
+    if (rs485_dir != mp_const_none) {
+      if ((rts != mp_const_none) || (cts != mp_const_none)) {
+        mp_raise_ValueError(translate("Cannot specify RTS or CTS in RS485 mode"));
+      }
+      // For IMXRT the RTS pin is used for RS485 direction
+      rts = rs485_dir;
+    }
+    else {
+      if (rs485_invert) {
+        mp_raise_ValueError(translate("RS485 inversion specified when not in RS485 mode"));
+      }
+    }
+
+    // Now check for RTS/CTS (or overloaded RS485 direction) pin(s)
+    const uint32_t rts_count = sizeof(mcu_uart_rts_list) / sizeof(mcu_periph_obj_t);
+    const uint32_t cts_count = sizeof(mcu_uart_cts_list) / sizeof(mcu_periph_obj_t);
+
+    if (rts != mp_const_none) {
+      for (uint32_t i=0; i < rts_count; ++i) {
+        if (mcu_uart_rts_list[i].bank_idx == self->rx_pin->bank_idx) {
+          if (mcu_uart_rts_list[i].pin == rts) {
+            self->rts_pin = &mcu_uart_rts_list[i];
+            break;
+          }
+        }
+      }
+      if (self->rts_pin == NULL)
+        mp_raise_ValueError(translate("Selected RTS pin not valid"));
+    }
+
+    if (cts != mp_const_none) {
+      for (uint32_t i=0; i < cts_count; ++i) {
+        if (mcu_uart_cts_list[i].bank_idx == self->rx_pin->bank_idx) {
+          if (mcu_uart_cts_list[i].pin == cts) {
+            self->cts_pin = &mcu_uart_cts_list[i];
+            break;
+          }
+        }
+      }
+      if (self->cts_pin == NULL)
+        mp_raise_ValueError(translate("Selected CTS pin not valid"));
+    }
+    
+    self->uart = mcu_uart_banks[self->tx_pin->bank_idx - 1];
+
     config_periph_pin(self->rx_pin);
     config_periph_pin(self->tx_pin);
+    if (self->rts_pin)
+      config_periph_pin(self->rts_pin);
+    if (self->cts_pin)
+      config_periph_pin(self->cts_pin);    
 
     lpuart_config_t config = { 0 };
     LPUART_GetDefaultConfig(&config);
@@ -125,10 +175,27 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
     config.baudRate_Bps = self->baudrate;
     config.enableTx = self->tx_pin != NULL;
     config.enableRx = self->rx_pin != NULL;
+    config.enableRxRTS = self->rts_pin != NULL;
+    config.enableTxCTS = self->cts_pin != NULL;
+    if (self->rts_pin != NULL)
+      claim_pin(self->rts_pin->pin);
+    if (self->cts_pin != NULL)
+      claim_pin(self->cts_pin->pin);
 
     LPUART_Init(self->uart, &config, UART_CLOCK_FREQ);
 
-    claim_pin(self->tx_pin->pin);
+    // Before we init, setup RS485 direction pin
+    // ..unfortunately this isn't done by the driver library
+    uint32_t modir = (self->uart->MODIR) & ~(LPUART_MODIR_TXRTSPOL_MASK | LPUART_MODIR_TXRTSE_MASK);
+    if (rs485_dir != mp_const_none) {
+      modir |= LPUART_MODIR_TXRTSE_MASK;
+      if (rs485_invert)
+        modir |= LPUART_MODIR_TXRTSPOL_MASK;
+    }
+    self->uart->MODIR = modir;
+
+    if (self->tx_pin != NULL)
+      claim_pin(self->tx_pin->pin);
 
     if (self->rx_pin != NULL) {
         ringbuf_alloc(&self->rbuf, receiver_buffer_size, true);
@@ -203,7 +270,9 @@ size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t
         LPUART_TransferAbortReceive(self->uart, &self->handle);
     }
 
-    return len - self->handle.rxDataSize;
+    // The only place we can reliably tell how many bytes have been received is from the current
+    // wp in the handle (because the abort nukes rxDataSize, and reading it before abort is a race.)
+    return self->handle.rxData-data;
 }
 
 // Write characters.
diff --git a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.c b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.c
index e9d735830f..2fed6dfc61 100644
--- a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.c
+++ b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.c
@@ -113,6 +113,26 @@ const mcu_periph_obj_t mcu_uart_tx_list[9] = {
     PERIPH_PIN(4, 3, kIOMUXC_LPUART4_TXD_SELECT_INPUT, 1, &pin_GPIO_06),
 };
 
+const mcu_periph_obj_t mcu_uart_rts_list[4] = {
+    PERIPH_PIN(1, 6, 0, 0, &pin_GPIO_07),
+   
+    PERIPH_PIN(2, 3, 0, 0, &pin_GPIO_AD_07),
+
+    PERIPH_PIN(3, 1, 0, 0, &pin_GPIO_AD_13),
+
+    PERIPH_PIN(4, 3, 0, 0, &pin_GPIO_AD_13)
+};
+
+const mcu_periph_obj_t mcu_uart_cts_list[4] = {
+    PERIPH_PIN(1, 6, 0, 0, &pin_GPIO_08),
+
+    PERIPH_PIN(2, 3, 0, 0, &pin_GPIO_AD_08),
+
+    PERIPH_PIN(3, 1, 0, 0, &pin_GPIO_AD_14),
+
+    PERIPH_PIN(4, 3, 0, 0, &pin_GPIO_AD_14),
+};
+
 const mcu_pwm_obj_t mcu_pwm_list[20] = {
     PWM_PIN(PWM1, kPWM_Module_0, kPWM_PwmA, 2, &pin_GPIO_02),
     PWM_PIN(PWM1, kPWM_Module_0, kPWM_PwmA, 2, &pin_GPIO_SD_02),
diff --git a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.h b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.h
index c91d5808af..d6d4895371 100644
--- a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.h
+++ b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1011/periph.h
@@ -36,6 +36,8 @@ extern const mcu_periph_obj_t mcu_spi_miso_list[4];
 
 extern const mcu_periph_obj_t mcu_uart_rx_list[9];
 extern const mcu_periph_obj_t mcu_uart_tx_list[9];
+extern const mcu_periph_obj_t mcu_uart_rts_list[4];
+extern const mcu_periph_obj_t mcu_uart_cts_list[4];
 
 extern const mcu_pwm_obj_t mcu_pwm_list[20];
 
diff --git a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.c b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.c
index 39e4f0131d..0417f29cc2 100644
--- a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.c
+++ b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.c
@@ -109,53 +109,93 @@ LPUART_Type *mcu_uart_banks[] = { LPUART1, LPUART2, LPUART3, LPUART4, LPUART5, L
 const mcu_periph_obj_t mcu_uart_rx_list[16] = {
     PERIPH_PIN(1, 2, 0, 0, &pin_GPIO_AD_B0_07),
 
-    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_23),
-    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_RX_SELECT_INPUT, 1, &pin_GPIO_AD_B1_09),
+    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_RX_SELECT_INPUT, 0, &pin_GPIO_AD_B1_09),
+    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_RX_SELECT_INPUT, 1, &pin_GPIO_EMC_23),
 
     PERIPH_PIN(3, 2, kIOMUXC_LPUART3_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_07),
     PERIPH_PIN(3, 2, kIOMUXC_LPUART3_RX_SELECT_INPUT, 1, &pin_GPIO_AD_B0_15),
 
     PERIPH_PIN(4, 2, kIOMUXC_LPUART4_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_03),
-    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_RX_SELECT_INPUT, 1, &pin_GPIO_EMC_33),
-    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_RX_SELECT_INPUT, 2, &pin_GPIO_AD_B1_11),
+    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_RX_SELECT_INPUT, 1, &pin_GPIO_AD_B1_11),
+    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_RX_SELECT_INPUT, 2, &pin_GPIO_EMC_33),
 
-    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_39),
-    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_RX_SELECT_INPUT, 1, &pin_GPIO_AD_B0_11),
+    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_RX_SELECT_INPUT, 0, &pin_GPIO_AD_B0_11),
+    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_RX_SELECT_INPUT, 1, &pin_GPIO_EMC_39),
 
     PERIPH_PIN(6, 2, kIOMUXC_LPUART6_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_13),
     PERIPH_PIN(6, 2, kIOMUXC_LPUART6_RX_SELECT_INPUT, 1, &pin_GPIO_SD_B1_01),
 
-    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_35),
-    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_RX_SELECT_INPUT, 1, &pin_GPIO_SD_B0_05),
+    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_RX_SELECT_INPUT, 0, &pin_GPIO_SD_B0_05),
+    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_RX_SELECT_INPUT, 1, &pin_GPIO_EMC_35),
 
-    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_27),
-    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_RX_SELECT_INPUT, 1, &pin_GPIO_SD_B1_03),
+    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_RX_SELECT_INPUT, 0, &pin_GPIO_SD_B1_03),
+    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_RX_SELECT_INPUT, 1, &pin_GPIO_EMC_27),
 };
 
 const mcu_periph_obj_t mcu_uart_tx_list[16] = {
     PERIPH_PIN(1, 2, 0, 0, &pin_GPIO_AD_B0_06),
 
-    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_TX_SELECT_INPUT, 0, &pin_GPIO_EMC_22),
-    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_TX_SELECT_INPUT, 1, &pin_GPIO_AD_B1_08),
+    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_TX_SELECT_INPUT, 0, &pin_GPIO_AD_B1_08),
+    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_TX_SELECT_INPUT, 1, &pin_GPIO_EMC_22),
 
     PERIPH_PIN(3, 2, kIOMUXC_LPUART3_TX_SELECT_INPUT, 0, &pin_GPIO_EMC_06),
     PERIPH_PIN(3, 2, kIOMUXC_LPUART3_TX_SELECT_INPUT, 1, &pin_GPIO_AD_B0_14),
 
     PERIPH_PIN(4, 2, kIOMUXC_LPUART4_TX_SELECT_INPUT, 0, &pin_GPIO_EMC_02),
-    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_TX_SELECT_INPUT, 1, &pin_GPIO_EMC_32),
-    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_TX_SELECT_INPUT, 2, &pin_GPIO_AD_B1_10),
+    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_TX_SELECT_INPUT, 1, &pin_GPIO_AD_B1_10),
+    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_TX_SELECT_INPUT, 2, &pin_GPIO_EMC_32),
 
-    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_TX_SELECT_INPUT, 0, &pin_GPIO_EMC_38),
-    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_TX_SELECT_INPUT, 1, &pin_GPIO_AD_B0_10),
+    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_TX_SELECT_INPUT, 0, &pin_GPIO_AD_B0_10),
+    PERIPH_PIN(5, 2, kIOMUXC_LPUART5_TX_SELECT_INPUT, 1, &pin_GPIO_EMC_38),
 
     PERIPH_PIN(6, 2, kIOMUXC_LPUART6_TX_SELECT_INPUT, 0, &pin_GPIO_EMC_12),
     PERIPH_PIN(6, 2, kIOMUXC_LPUART6_TX_SELECT_INPUT, 1, &pin_GPIO_SD_B1_00),
 
-    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_TX_SELECT_INPUT, 0, &pin_GPIO_EMC_34),
-    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_TX_SELECT_INPUT, 1, &pin_GPIO_SD_B0_04),
+    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_TX_SELECT_INPUT, 0, &pin_GPIO_SD_B0_04),
+    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_TX_SELECT_INPUT, 1, &pin_GPIO_EMC_34),
 
-    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_TX_SELECT_INPUT, 0, &pin_GPIO_EMC_26),
-    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_TX_SELECT_INPUT, 1, &pin_GPIO_SD_B1_02),
+    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_TX_SELECT_INPUT, 0, &pin_GPIO_SD_B1_02),
+    PERIPH_PIN(8, 2, kIOMUXC_LPUART8_TX_SELECT_INPUT, 1, &pin_GPIO_EMC_26),
+};
+
+const mcu_periph_obj_t mcu_uart_rts_list[10] = {
+    PERIPH_PIN(1, 2, 0, 0, &pin_GPIO_AD_B0_09),
+   
+    PERIPH_PIN(2, 2, 0, 0, &pin_GPIO_EMC_21),
+    PERIPH_PIN(2, 2, 0, 1, &pin_GPIO_AD_B1_07),
+
+    PERIPH_PIN(3, 2, 0, 1, &pin_GPIO_AD_B0_13),
+
+    PERIPH_PIN(4, 2, 0, 0, &pin_GPIO_EMC_01),
+    PERIPH_PIN(4, 2, 0, 1, &pin_GPIO_EMC_31),
+
+    PERIPH_PIN(5, 2, 0, 0, &pin_GPIO_EMC_37),
+
+    PERIPH_PIN(6, 2, 0, 0, &pin_GPIO_EMC_15),
+
+    PERIPH_PIN(7, 2, 0, 1, &pin_GPIO_SD_B0_03),
+
+    PERIPH_PIN(8, 2, 0, 0, &pin_GPIO_EMC_25),
+};
+
+const mcu_periph_obj_t mcu_uart_cts_list[10] = {
+    PERIPH_PIN(1, 2, 0, 0, &pin_GPIO_AD_B0_08),
+
+    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_CTS_B_SELECT_INPUT, 0, &pin_GPIO_AD_B1_06),
+    PERIPH_PIN(2, 2, kIOMUXC_LPUART2_CTS_B_SELECT_INPUT, 1, &pin_GPIO_EMC_20),
+
+    PERIPH_PIN(3, 2, 0, 1, &pin_GPIO_AD_B0_12),
+
+    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_CTS_B_SELECT_INPUT, 0, &pin_GPIO_EMC_00),
+    PERIPH_PIN(4, 2, kIOMUXC_LPUART4_CTS_B_SELECT_INPUT, 0, &pin_GPIO_EMC_30),
+
+    PERIPH_PIN(5, 2, 0, 0, &pin_GPIO_EMC_36),
+
+    PERIPH_PIN(6, 2, 0, 0, &pin_GPIO_EMC_14),
+
+    PERIPH_PIN(7, 2, 0, 0, &pin_GPIO_SD_B0_02),
+
+    PERIPH_PIN(8, 2, 0, 0, &pin_GPIO_EMC_24),
 };
 
 const mcu_pwm_obj_t mcu_pwm_list[39] = {
diff --git a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.h b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.h
index 1d720f6336..ba88ef4c61 100644
--- a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.h
+++ b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1021/periph.h
@@ -37,6 +37,8 @@ extern const mcu_periph_obj_t mcu_spi_miso_list[8];
 
 extern const mcu_periph_obj_t mcu_uart_rx_list[16];
 extern const mcu_periph_obj_t mcu_uart_tx_list[16];
+extern const mcu_periph_obj_t mcu_uart_rts_list[10];
+extern const mcu_periph_obj_t mcu_uart_cts_list[10];
 
 extern const mcu_pwm_obj_t mcu_pwm_list[39];
 
diff --git a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.c b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.c
index 3f0473a886..9a1a4ab65c 100644
--- a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.c
+++ b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.c
@@ -127,8 +127,8 @@ const mcu_periph_obj_t mcu_uart_rx_list[18] = {
     PERIPH_PIN(6, 2, kIOMUXC_LPUART6_RX_SELECT_INPUT, 0, &pin_GPIO_EMC_26),
     PERIPH_PIN(6, 2, kIOMUXC_LPUART6_RX_SELECT_INPUT, 1, &pin_GPIO_AD_B0_03),
 
-    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_RX_SELECT_INPUT, 1, &pin_GPIO_EMC_32),
     PERIPH_PIN(7, 2, kIOMUXC_LPUART7_RX_SELECT_INPUT, 0, &pin_GPIO_SD_B1_09),
+    PERIPH_PIN(7, 2, kIOMUXC_LPUART7_RX_SELECT_INPUT, 1, &pin_GPIO_EMC_32),
 
     PERIPH_PIN(8, 2, kIOMUXC_LPUART8_RX_SELECT_INPUT, 0, &pin_GPIO_SD_B0_05),
     PERIPH_PIN(8, 2, kIOMUXC_LPUART8_RX_SELECT_INPUT, 1, &pin_GPIO_AD_B1_11),
@@ -163,6 +163,44 @@ const mcu_periph_obj_t mcu_uart_tx_list[18] = {
     PERIPH_PIN(8, 2, kIOMUXC_LPUART8_TX_SELECT_INPUT, 2, &pin_GPIO_EMC_38),
 };
 
+const mcu_periph_obj_t mcu_uart_rts_list[9] = {
+    PERIPH_PIN(1, 2, 0, 0, &pin_GPIO_AD_B0_15),
+   
+    PERIPH_PIN(2, 2, 0, 0, &pin_GPIO_AD_B1_01),
+
+    PERIPH_PIN(3, 2, 0, 0, &pin_GPIO_AD_B1_05),
+    PERIPH_PIN(3, 2, 0, 0, &pin_GPIO_EMC_16),
+
+    PERIPH_PIN(4, 2, 0, 0, &pin_GPIO_EMC_18),
+
+    PERIPH_PIN(5, 2, 0, 0, &pin_GPIO_EMC_27),
+
+    PERIPH_PIN(6, 2, 0, 0, &pin_GPIO_EMC_29),
+
+    PERIPH_PIN(7, 2, 0, 0, &pin_GPIO_SD_B1_07),
+
+    PERIPH_PIN(8, 2, 0, 0, &pin_GPIO_SD_B0_03),
+};
+
+const mcu_periph_obj_t mcu_uart_cts_list[9] = {
+    PERIPH_PIN(1, 2, 0, 0, &pin_GPIO_AD_B0_14),
+
+    PERIPH_PIN(2, 2, 0, 0, &pin_GPIO_AD_B1_00),
+
+    PERIPH_PIN(3, 2, kIOMUXC_LPUART3_CTS_B_SELECT_INPUT, 0, &pin_GPIO_EMC_15),
+    PERIPH_PIN(3, 2, kIOMUXC_LPUART3_CTS_B_SELECT_INPUT, 1, &pin_GPIO_AD_B1_04),    
+
+    PERIPH_PIN(4, 2, 0, 0, &pin_GPIO_EMC_17),
+
+    PERIPH_PIN(5, 2, 0, 0, &pin_GPIO_EMC_28),
+
+    PERIPH_PIN(6, 2, 0, 0, &pin_GPIO_EMC_30),
+
+    PERIPH_PIN(7, 2, 0, 0, &pin_GPIO_SD_B1_06),
+
+    PERIPH_PIN(8, 2, 0, 0, &pin_GPIO_SD_B0_02),
+};
+
 const mcu_pwm_obj_t mcu_pwm_list[67] = {
     PWM_PIN(PWM1, kPWM_Module_0, kPWM_PwmA, 1, &pin_GPIO_EMC_23),
     PWM_PIN(PWM1, kPWM_Module_0, kPWM_PwmA, 1, &pin_GPIO_SD_B0_00),
diff --git a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.h b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.h
index b069ca76bb..45b92f2473 100644
--- a/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.h
+++ b/ports/mimxrt10xx/peripherals/mimxrt10xx/MIMXRT1062/periph.h
@@ -36,6 +36,8 @@ extern const mcu_periph_obj_t mcu_spi_miso_list[8];
 
 extern const mcu_periph_obj_t mcu_uart_rx_list[18];
 extern const mcu_periph_obj_t mcu_uart_tx_list[18];
+extern const mcu_periph_obj_t mcu_uart_rts_list[9];
+extern const mcu_periph_obj_t mcu_uart_cts_list[9];
 
 extern const mcu_pwm_obj_t mcu_pwm_list[67];
 
diff --git a/ports/mimxrt10xx/supervisor/flexspi_nor_flash_ops.c b/ports/mimxrt10xx/supervisor/flexspi_nor_flash_ops.c
index 71252d6776..28d5115ac7 100644
--- a/ports/mimxrt10xx/supervisor/flexspi_nor_flash_ops.c
+++ b/ports/mimxrt10xx/supervisor/flexspi_nor_flash_ops.c
@@ -324,7 +324,11 @@ void flexspi_nor_flash_init(FLEXSPI_Type *base)
     config.ahbConfig.enableAHBBufferable  = true;
     config.ahbConfig.enableReadAddressOpt = true;
     config.ahbConfig.enableAHBCachable    = true;
+#ifdef BOARD_USING_SECONDARY_QSPI_PINMUX
+    config.rxSampleClock                  = kFLEXSPI_ReadSampleClkLoopbackInternally;
+#else
     config.rxSampleClock                  = kFLEXSPI_ReadSampleClkLoopbackFromDqsPad;
+#endif
     FLEXSPI_Init(base, &config);
 
     /* Configure flash settings according to serial flash feature. */
diff --git a/ports/nrf/common-hal/busio/UART.c b/ports/nrf/common-hal/busio/UART.c
index d79b65ff81..933faf17b8 100644
--- a/ports/nrf/common-hal/busio/UART.c
+++ b/ports/nrf/common-hal/busio/UART.c
@@ -128,10 +128,17 @@ void uart_reset(void) {
     }
 }
 
-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, mp_float_t timeout,
-                                      uint16_t receiver_buffer_size) {
+void common_hal_busio_uart_construct(busio_uart_obj_t *self,
+    const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
+    const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
+    const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
+    uint32_t baudrate, uint8_t bits, uart_parity_t parity, uint8_t stop,
+    mp_float_t timeout, uint16_t receiver_buffer_size) {
+
+    if ((rts != mp_const_none) || (cts != mp_const_none) || (rs485_dir != mp_const_none) || (rs485_invert)) {
+        mp_raise_ValueError(translate("RTS/CTS/RS485 Not yet supported on this device"));
+    }
+  
     // Find a free UART peripheral.
     self->uarte = NULL;
     for (size_t i = 0 ; i < MP_ARRAY_SIZE(nrfx_uartes); i++) {
diff --git a/ports/stm32f4/common-hal/busio/UART.c b/ports/stm32f4/common-hal/busio/UART.c
index bfa541c17d..3c19092591 100644
--- a/ports/stm32f4/common-hal/busio/UART.c
+++ b/ports/stm32f4/common-hal/busio/UART.c
@@ -71,10 +71,12 @@ void uart_reset(void) {
     uart_clock_disable(ALL_UARTS);
 }
 
-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, mp_float_t timeout,
-        uint16_t receiver_buffer_size) {
+void common_hal_busio_uart_construct(busio_uart_obj_t *self,
+    const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
+    const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
+    const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
+    uint32_t baudrate, uint8_t bits, uart_parity_t parity, uint8_t stop,
+    mp_float_t timeout, uint16_t receiver_buffer_size) {
 
     //match pins to UART objects
     USART_TypeDef * USARTx;
@@ -84,6 +86,10 @@ void common_hal_busio_uart_construct(busio_uart_obj_t* self,
     bool uart_taken = false;
     uint8_t uart_index = 0; //origin 0 corrected
 
+    if ((rts != mp_const_none) || (cts != mp_const_none) || (rs485_dir != mp_const_none) || (rs485_invert == true)) {
+        mp_raise_ValueError(translate("RTS/CTS/RS485 Not yet supported on this device"));
+    }
+    
     //Can have both pins, or either
     if ((tx != mp_const_none) && (rx != mp_const_none)) {
         //normal find loop if both pins exist
diff --git a/shared-bindings/busio/UART.c b/shared-bindings/busio/UART.c
index 1fc81e78e2..02c5afb16e 100644
--- a/shared-bindings/busio/UART.c
+++ b/shared-bindings/busio/UART.c
@@ -53,6 +53,10 @@
 //|
 //|   :param ~microcontroller.Pin tx: the pin to transmit with, or ``None`` if this ``UART`` is receive-only.
 //|   :param ~microcontroller.Pin rx: the pin to receive on, or ``None`` if this ``UART`` is transmit-only.
+//|   :param ~microcontroller.Pin rts: the pin for rts, or ``None`` if rts not in use.
+//|   :param ~microcontroller.Pin cts: the pin for cts, or ``None`` if cts not in use.
+//|   :param ~microcontroller.Pin rs485_dir: the pin for rs485 direction setting, or ``None`` if rs485 not in use.
+//|   :param bool rs485_invert: set to invert the sense of the rs485_dir pin.
 //|   :param int baudrate: the transmit and receive speed.
 //|   :param int bits:  the number of bits per byte, 7, 8 or 9.
 //|   :param Parity parity:  the parity used for error checking.
@@ -82,7 +86,8 @@ STATIC mp_obj_t busio_uart_make_new(const mp_obj_type_t *type, size_t n_args, co
     // https://github.com/adafruit/circuitpython/issues/1056)
     busio_uart_obj_t *self = m_new_ll_obj(busio_uart_obj_t);
     self->base.type = &busio_uart_type;
-    enum { ARG_tx, ARG_rx, ARG_baudrate, ARG_bits, ARG_parity, ARG_stop, ARG_timeout, ARG_receiver_buffer_size};
+    enum { ARG_tx, ARG_rx, ARG_baudrate, ARG_bits, ARG_parity, ARG_stop, ARG_timeout, ARG_receiver_buffer_size,
+           ARG_rts, ARG_cts, ARG_rs485_dir,ARG_rs485_invert};
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_tx, MP_ARG_REQUIRED | MP_ARG_OBJ },
         { MP_QSTR_rx, MP_ARG_REQUIRED | MP_ARG_OBJ },
@@ -92,6 +97,10 @@ STATIC mp_obj_t busio_uart_make_new(const mp_obj_type_t *type, size_t n_args, co
         { MP_QSTR_stop, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
         { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NEW_SMALL_INT(1)} },
         { MP_QSTR_receiver_buffer_size, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 64} },
+        { MP_QSTR_rts, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+        { MP_QSTR_cts, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+        { MP_QSTR_rs485_dir, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none } },
+        { MP_QSTR_rs485_invert, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false } },
     };
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
     mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
@@ -124,7 +133,14 @@ STATIC mp_obj_t busio_uart_make_new(const mp_obj_type_t *type, size_t n_args, co
     mp_float_t timeout = mp_obj_get_float(args[ARG_timeout].u_obj);
     validate_timeout(timeout);
 
-    common_hal_busio_uart_construct(self, tx, rx,
+    const mcu_pin_obj_t* rts = MP_OBJ_TO_PTR(args[ARG_rts].u_obj);
+
+    const mcu_pin_obj_t* cts = MP_OBJ_TO_PTR(args[ARG_cts].u_obj);
+
+    const mcu_pin_obj_t* rs485_dir = args[ARG_rs485_dir].u_obj;
+    bool rs485_invert = args[ARG_rs485_invert].u_bool;
+
+    common_hal_busio_uart_construct(self, tx, rx, rts, cts, rs485_dir, rs485_invert,
                                     args[ARG_baudrate].u_int, bits, parity, stop, timeout,
                                     args[ARG_receiver_buffer_size].u_int);
     return (mp_obj_t)self;
diff --git a/shared-bindings/busio/UART.h b/shared-bindings/busio/UART.h
index cfd2c800c3..fe71e86689 100644
--- a/shared-bindings/busio/UART.h
+++ b/shared-bindings/busio/UART.h
@@ -40,9 +40,11 @@ typedef enum {
 
 // Construct an underlying UART object.
 extern 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, mp_float_t timeout,
-    uint16_t receiver_buffer_size);
+    const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
+    const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
+    const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
+    uint32_t baudrate, uint8_t bits, uart_parity_t parity, uint8_t stop,
+    mp_float_t timeout, uint16_t receiver_buffer_size);
 
 extern void common_hal_busio_uart_deinit(busio_uart_obj_t *self);
 extern bool common_hal_busio_uart_deinited(busio_uart_obj_t *self);
diff --git a/shared-module/board/__init__.c b/shared-module/board/__init__.c
index 914bc43137..952e1fc10c 100644
--- a/shared-module/board/__init__.c
+++ b/shared-module/board/__init__.c
@@ -100,8 +100,28 @@ mp_obj_t common_hal_board_create_uart(void) {
 
     const mcu_pin_obj_t* rx = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_RX);
     const mcu_pin_obj_t* tx = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_TX);
+#ifdef DEFAULT_UART_BUS_RTS
+    const mcu_pin_obj_t* rts = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_RTS);
+#else
+    const mcu_pin_obj_t* rts = mp_const_none;
+#endif
+#ifdef DEFAULT_UART_BUS_CTS
+    const mcu_pin_obj_t* cts = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_CTS);
+#else
+    const mcu_pin_obj_t* cts = mp_const_none;
+#endif
+#ifdef DEFAULT_UART_IS_RS485
+    const mcu_pin_obj_t* rs485_dir = MP_OBJ_TO_PTR(DEFAULT_UART_BUS_RS485DIR);
+#ifdef DEFAULT_UART_RS485_INVERT
+    const bool rs485_invert = true;
+#endif
+#else
+    const mcu_pin_obj_t* rs485_dir = mp_const_none;
+    const bool rs485_invert = true;
+#endif
 
-    common_hal_busio_uart_construct(self, tx, rx, 9600, 8, PARITY_NONE, 1, 1.0f, 64);
+    common_hal_busio_uart_construct(self, tx, rx, rts, cts, rs485_dir, rs485_invert,
+                                    9600, 8, PARITY_NONE, 1, 1.0f, 64);
     MP_STATE_VM(shared_uart_bus) = MP_OBJ_FROM_PTR(self);
     return MP_STATE_VM(shared_uart_bus);
 }