diff --git a/docs/device/serial.md b/docs/device/serial.md
index 7daacf8d..28d5a1dd 100644
--- a/docs/device/serial.md
+++ b/docs/device/serial.md
@@ -32,6 +32,8 @@ If you are using the Google Chrome browser, you can use our extension to get ser
 * Restart Chrome and open the [web editor](https://pxt.microbit.org)
 * The serial data will show below the simulator
 
+If the extension is enabled, it will not be possible to access the port/device for the micro:bit from other programs than Chrome.
+
 ### Windows
 
 You must install a device driver (for the computer to recognize the
diff --git a/docs/projects.md b/docs/projects.md
index 905b3eeb..92dd38cd 100644
--- a/docs/projects.md
+++ b/docs/projects.md
@@ -10,8 +10,7 @@ Fun games to build with your @boardname@.
 [{
   "name": "Flashing Heart",
   "url":"/projects/flashing-heart",
-  "imageUrl": "/static/mb/projects/a1-display.png",
-  "cardType": "tutorial"
+  "imageUrl": "/static/mb/projects/a1-display.png"
 },{
   "name": "Smiley Buttons",
   "url":"/projects/smiley-buttons",
diff --git a/libs/core/_locales/core-strings.json b/libs/core/_locales/core-strings.json
index cb5f38ea..edc5825d 100644
--- a/libs/core/_locales/core-strings.json
+++ b/libs/core/_locales/core-strings.json
@@ -28,6 +28,7 @@
   "BaudRate.BaudRate28800|block": "28800",
   "BaudRate.BaudRate300|block": "300",
   "BaudRate.BaudRate38400|block": "38400",
+  "BaudRate.BaudRate31250|block": "31250",
   "BaudRate.BaudRate4800|block": "4800",
   "BaudRate.BaudRate57600|block": "57600",
   "BaudRate.BaudRate9600|block": "9600",
diff --git a/libs/core/enums.d.ts b/libs/core/enums.d.ts
index 8ede4a03..8699bcd0 100644
--- a/libs/core/enums.d.ts
+++ b/libs/core/enums.d.ts
@@ -447,6 +447,8 @@ declare namespace led {
     BaudRate57600 = 57600,
     //% block=38400
     BaudRate38400 = 38400,
+    //% block=31250
+    BaudRate31250 = 31250,
     //% block=28800
     BaudRate28800 = 28800,
     //% block=19200
diff --git a/libs/core/serial.cpp b/libs/core/serial.cpp
index 3b53a253..4d9a7894 100644
--- a/libs/core/serial.cpp
+++ b/libs/core/serial.cpp
@@ -19,6 +19,8 @@ enum BaudRate {
   BaudRate57600 = 57600,
   //% block=38400
   BaudRate38400 = 38400,
+  //% block=31250
+  BaudRate31250 = 31250,
   //% block=28800
   BaudRate28800 = 28800,
   //% block=19200