add README.md

Author: edy555

Makefile

@@ -239,7 +239,6 @@ include $(RULESPATH)/rules.mk
 flash: all
 	arm-none-eabi-gdb -x flash.gdb --silent
 
-
 RELEASE=$(shell date +%Y%m%d)
 DIST_FILES= build/ch.bin build/ch.hex build/ch.elf
 

README.md

@@ -0,0 +1,72 @@
+CentSDR - Tiny Standalone Software Defined Receiver
+==========================================================
+
+<div align="center">
+<img src="/doc/centsdr.jpg" width="480px">
+</div>
+
+# About
+
+CentSDR is tiny handheld standalone software defined receiver with LCD display,
+that is simple, low budget, but has reasonable perfomance.
+This project is aimed at contributing to studies, experiments and educations around
+RF technology. 
+
+# Block Diagram
+
+<div align="center">
+<img src="/doc/centsdr-blockdiagram.png" width="480px">
+</div>
+
+# Build Firmware
+
+## Prepare ARM Cross Tools
+
+Install cross tools and firmware updating tool.
+ 
+    $ brew tap PX4/homebrew-px4
+    $ brew install gcc-arm-none-eabi
+	
+## Fetch Source
+
+Clone source code from github.
+
+    $ git clone https://github.com/ttrftech/CentSDR centsdr
+
+Then fetch ChibiOS submodule into tree.
+
+    $ cd centsdr
+    $ git submodule update --init --recursive
+
+Just make in the top directory.
+
+    $ make
+
+## Flash firmware using st-util and gdb
+
+Prepare stlink utilities.
+
+    $ brew install stlink
+
+Connect target board via SWD with ST-Link2, In other terminal, launch st-util
+
+    $ st-util
+
+Then, flash the firmware.
+
+    $ make flash
+
+## Flash firmware using Nucleo st-link v2.1
+
+Or you can flash the firmware using Nucleo. First, mount as usb mass storage device, then copy 'build/ch.bin' file into mounted volume.
+
+## Attention
+
+This repository contains only source of CentSDR firmware, but NO hardware design resources.
+
+## Reference
+
+* Kit available from http://ttrftech.tumblr.com/kit/centsdr
+* Credit: @edy555
+
+[EOF]