first release.

Author: shaoziyang

NeoPixel_RGB_16x16_Matrix.jpg

@@ -1,2 +1,80 @@
 # snowflake
+
 makecode snow flake extension for 16x16 neopixel matrix display
+
+Author: shaoziyang  
+Date:   2018.Dec  
+
+![](NeoPixel_RGB_16x16_Matrix.jpg)
+
+## Add extension
+
+open your microbit makecode project, in Add extension, paste  
+
+https://github.com/makecode-extensions/snowflake  
+
+to search box then search.
+
+
+## Basic usage
+```
+snowflake.config(
+DigitalPin.P1,
+true,
+8,
+50,
+1,
+50
+)
+snowflake.start()
+```
+
+## API
+
+
+- **function load_background(dat: number[])**  
+Load a user back ground picture.  
+You may using microbittoolbox to convert data and paste to javascript code.  
+https://github.com/shaoziyang/microbit-lib/tree/master/utils/microbit_toolbox  
+
+- **function load_default_backgroud()**  
+Load default back ground: christmas tree
+
+- **function config(pin: DigitalPin, cover: boolean, threshold: number, snowfall: number, MostAtATime: number, speed: number)**  
+configurate snow, you may adjust paramters to get different effect.
+  * pin, which is used to control neopixel matrix
+  * cover, enable/disable snow cover effect
+  * threshold, snow cover threshold, range is [1-100]
+  * snowfall, how much snow is falling, range is [1-100]
+  * MostAtATime, new snowflake most at a time
+  * speed, snowfall speed, the bigger the slower  
+  
+
+- **function start()**  
+start/resume snowfall. Function start() need to be called only once, not in a loop.
+
+- **function pause()**  
+pause snowfall.
+
+- **function reset()**  
+restart.
+
+
+
+## Demo
+
+![](demo.png)
+
+![](run.gif)
+
+## License
+
+MIT
+
+Copyright (c) 2018, microbit/micropython Chinese community  
+
+## Supported targets
+
+* for PXT/microbit
+
+[From microbit/micropython Chinese community](http://www.micropython.org.cn)

README.md

@@ -0,0 +1,18 @@
+{
+    "name": "snowflake",
+    "version": "1.0.0",
+    "description": "snowflake christmas tree extension for 16 x 16 neopixel matrix",
+    "license": "MIT",
+    "dependencies": {
+        "core": "*",
+        "neopixel": "github:microsoft/pxt-neopixel#v0.6.10"
+    },
+    "files": [
+        "README.md",
+        "snowflake.ts"
+    ],
+    "testFiles": [
+        "test.ts"
+    ],
+    "public": true
+}