update readme

README.md

@@ -23,7 +23,7 @@ HTTP endpoints:
   /files -> GET returns list of files  
 
 # Install
-- install arduino ide (1.8.5)  
+- install arduino ide (1.8.5) or PlatformIO (see Development section for further instructions)  
 
 - follow this instruction
   https://github.com/esp8266/Arduino#installing-with-boards-manager
@@ -43,12 +43,52 @@ You may also need to:
   https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
 
 # Development  
+PlatformIO
+----------
+The project is intended to run on PlatformIO and the build environment is configured for NodeMCU 0.9 (ESP-12 Module).  
+More informations: http://docs.platformio.org/en/latest/platforms/espressif8266.html    
+  
+Following libraries need to be installed via PIO Home / Libraries:  
+- SoftwareSerial
+- ArduinoJson
+
+Use following commands to build and upload the firmware and filesystem:  
+```
+# clean the build directory  
+pio run -t clean  
+
+# run default build job  / build the formware
+pio run  
+
+# upload the firmware  
+pio run -e nodemcu -t upload  
+
+# build the filesystem  
+pio run -t buildfs  
+
+# upload the filesystem  
+pio run -t uploadfs  
+
+```
+  
+PlatformIO tasks can also be triggered with following npm run commands (pio / platformio executable needs to be in $PATH):  
+```
+build:fs
+upload:fs
+build:firmware
+upload:firmware
+```
+
 Frontend
 --------
-Frontend development requires NodeJS / NPM.  
-  
-Run development server:  
+Frontend development requires NodeJS / npm.  
+The development server watches all files in the frontend directory and automatically builds and copies the frontend code to the data folder.  
+
+```
+# run development server on port 8080
 npm run dev  
   
-Build distribution source:  
-npm run build
+# build distribution source to data folder  
+npm run build  
+```
+