mood radio activity (#889)

* new activity

* displaying mood on screen

* added challenge

* fix full sample

* missing radio package

docs/SUMMARY.md

@@ -23,6 +23,7 @@
     * [Plant Watering](/projects/plant-watering)
     * [Reaction Time](/projects/reaction-time)
     * [States of Matter](/projects/states-of-matter)
+    * [Mood radio](/projects/mood-radio)
     * [Tele-Potato](/projects/tele-potato)
     * [Hot Or Cold](/projects/hot-or-cold)
     * [Voting Machine](/projects/voting-machine)

docs/projects.md

@@ -25,6 +25,10 @@ Fun games to build with your @boardname@.
 ## Multiplayer Games
 ```codecard
 [{
+  "name": "Mood Radio",
+  "url": "/projects/mood-radio",
+  "imageUrl": "/static/mb/projects/mood-radio.png"
+}, {
   "name": "Tele-potato",
   "url": "/projects/tele-potato",
   "imageUrl": "/static/mb/projects/tele-potato.png"

docs/projects/mood-radio.md

@@ -0,0 +1,93 @@
+# Mood Radio
+
+## @description A mini mood messaging app using radio
+
+![@boardname@ sending moods around](/static/mb/projects/mood-radio.png)
+
+This project uses the [radio](/reference/radio) to share your mood with other @boardname@.
+When you press ``A``, you friends will see a **smilley**. When you press ``B``, they will see a **frownie**.
+
+## Sending a smiley
+
+The @boardname@ can't understand mood but it is pretty good with numbers. In fact, it can send numbers
+between @boardname@ using the radio antenna, just like phones.
+
+Let's add blocks that send a number when button ``A`` is pressed. In our "code", 
+we assume that **0** means "smiley".
+
+```blocks
+input.onButtonPressed(Button.A, () => {
+    radio.sendNumber(0)
+    basic.showIcon(IconNames.Happy)
+})
+```
+
+## Receiving a smiley
+
+We add a ``radio on received`` block that will run code whenever a new message code in.
+The ``receivedNumber`` variable contain the numeric value that was sent. Since we've decided that
+**0** was **smiley**, we add a conditional **if** statement to show this icon.
+
+```blocks
+radio.onDataPacketReceived( ({ receivedNumber }) =>  {
+    if (receivedNumber == 0) {
+        basic.showIcon(IconNames.Happy)
+    }
+})
+```
+
+## Sending a frowney
+
+Adding another code in our messaging app is very similar. We decide that **1** means **forwnie**.
+Then we can add a ``B`` button event that sends that code.
+
+```blocks
+input.onButtonPressed(Button.B, () => {
+    radio.sendNumber(1)
+    basic.showIcon(IconNames.Sad)
+})
+```
+
+If the ``on radio received`` block, we add an conditional **if** statement to handle the new code.
+
+```blocks
+radio.onDataPacketReceived( ({ receivedNumber }) =>  {
+    if (receivedNumber == 0) {
+        basic.showIcon(IconNames.Happy)
+    }
+    if (receivedNumber == 1) {
+        basic.showIcon(IconNames.Sad)
+    }
+})
+```
+
+That's it. Download your code in multiple @boardname@ and try it out!
+
+## Challenges
+
+Try adding a new code and use the **shake** event to send it.
+
+## Full sources
+
+```blocks
+input.onButtonPressed(Button.A, () => {
+    radio.sendNumber(0)
+    basic.showIcon(IconNames.Happy)
+})
+input.onButtonPressed(Button.B, () => {
+    radio.sendNumber(1)
+    basic.showIcon(IconNames.Sad)
+})
+radio.onDataPacketReceived( ({ receivedNumber }) =>  {
+    if (receivedNumber == 0) {
+        basic.showIcon(IconNames.Happy)
+    }
+    if (receivedNumber == 1) {
+        basic.showIcon(IconNames.Sad)
+    }
+})
+```
+
+```package
+radio
+```

docs/projects/tele-potato.md

@@ -2,6 +2,12 @@
 
 ## @description The famous "Hot Potato" game revisit for @boardname@
 
+## ~ avatar
+
+Don't keep the potato too long or you might loose the game!
+
+## ~
+
 ![A teleporting potato](/static/mb/projects/tele-potato.png)
 
 Do you know the "Hot Potato" game? You usually toss around a potato with a timer