fireflew activity (#410)

docs/projects/fireflies.md

@@ -0,0 +1,109 @@
+
+# Fireflies
+
+### ~ avatar
+
+Turn your @boardname@ into fireflies.
+
+### ~
+
+https://youtu.be/ZGvtnE1Wy6U
+
+## How do Fireflies synchronise?
+
+Go to http://ncase.me/fireflies/ and read about the fireflies synchronization phenomenon.
+
+## Code
+
+The goal of this project is to create virtual fireflies using @boardname@ that mimic the real fireflies. 
+After reading the article, there are a few sentences that stand out to help.
+
+### "Each firefly has its own individual internal clock"
+
+A clock in this case is like a counter, so we will start by adding a ``clock`` variable to our program.
+
+```block
+// the clock ticker
+let clock = 1
+```
+
+### "and every time the clock “strikes twelve”, it flashes."
+
+So we need a [forever](/reference/basic/forever) loop to increment the clock.
+When the clock reaches "noon" (let's pick 8), we turn on the screen breifly.
+
+```block
+// the clock ticker
+let clock = 0
+basic.forever(() => {
+    // if clock "hits noon", flash the screen
+    if (clock >= 8) {
+        // flash
+        game.addScore(1)
+        // wait for 2 ticks + a tiny bit
+        basic.pause(220)
+        // reset the clock
+        clock = 0
+    } else {
+        // just wait a bit
+        basic.pause(100)
+        // increment the clock
+        clock += 1
+    }
+})
+```
+
+### Step 1: when you see a nearby firefly flash, nudge your clock a little bit forward.
+
+We will use radio messages to simulate the vision of fireflies. 
+
+* When a firefly flashes, it also sends a number over radio using [radio send number](/reference/radio/send-number).
+* When a firefly receives a radio packet, it increments its clock by one just like the fireflies.
+
+```block
+// the clock ticker
+let clock = 0
+radio.onDataPacketReceived(() => {
+    // advance clock to catch up neighbors
+    clock += 1
+})
+```
+
+### Putting all together
+
+https://youtu.be/XzZeB4yYnEw
+
+
+Now that we have all the parts needed to build our firefly simulator, we can assemble it into a program.
+
+We've add a [radio set group](/reference/radio/set-group) block to specify which group the firefly will communicate on. Download this program on as many @boardname@ as you can find and try it out in a dark room!
+
+```blocks
+// the clock ticker
+let clock = 0
+radio.onDataPacketReceived(() => {
+    // advance clock to catch up neighbors
+    clock += 1
+})
+basic.forever(() => {
+    // if clock hits noon, flash the screen
+    if (clock >= 8) {
+        // notify neighbors
+        radio.sendNumber(clock)
+        // flash
+        game.addScore(1)
+        // wait for 2 ticks + a tiny bit
+        basic.pause(220)
+        // reset the clock
+        clock = 0
+    } else {
+        // just wait a bit
+        basic.pause(100)
+        // increment the clock
+        clock += 1
+    }
+})
+// short range radio transmission
+radio.setTransmitPower(1)
+radio.setGroup(12)
+```

docs/projects/infection.md

@@ -9,6 +9,8 @@ There is a disease outbreak! Will you find patient zero?!?
 **Infection** is a distributed game which simulates 
 the propagation of an illness. **The goal is to stop the outbreak before every player dies!**
 
+* **Number of players:** 1 Master, 4 or more players. Each Master and players need a @boardname@ with battery pack.
+
 In this game, a master @boardname@ infects a "patient zero" player
 with the sickness. The infected player will be contagious immediately but won't show any sign 
 during the incubation time. The sickness gets transmitted when two @boardname@ get close to each other.