diff --git a/platformio.ini b/platformio.ini
index ab5b9a3..a031006 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -22,7 +22,7 @@ env_default = emonesp
 data_dir = src/data
 
 [common]
-version = -DBUILD_TAG=2.3.0
+version = -DBUILD_TAG=2.3.1
 lib_deps = PubSubClient@2.6, ESP Async WebServer@1.1.1
 monitor_speed = 115200
 
@@ -31,7 +31,7 @@ monitor_speed = 115200
 platform = https://github.com/platformio/platform-espressif8266.git#feature/2.4.0-rc2
 
 [env:emonesp]
-platform = espressif8266
+platform = espressif8266@1.8.0
 framework = arduino
 board = esp12e
 lib_deps = ${common.lib_deps}
@@ -41,7 +41,7 @@ monitor_speed = ${common.monitor_speed}
 
 [env:emonesp_fast]
 # Upload at faster baud reate 50s upload reduced to  20s :-)
-platform = espressif8266
+platform = espressif8266@1.8.0
 framework = arduino
 board = esp12e
 lib_deps = ${common.lib_deps}
@@ -51,7 +51,7 @@ monitor_speed = ${common.monitor_speed}
 
 
 [env:emonesp_ota]
-platform = espressif8266
+platform = espressif8266@1.8.0
 framework = arduino
 board = esp12e
 upload_port = emonesp.local
@@ -60,7 +60,7 @@ src_build_flags = ${common.version} -DWIFI_LED=0 -DENABLE_DEBUG
 monitor_speed = ${common.monitor_speed}
 
 [env:emonesp_spiffs]
-platform = espressif8266
+platform = espressif8266@1.8.0
 framework = arduino
 board = esp12e
 lib_deps = ${common.lib_deps}
@@ -70,14 +70,14 @@ monitor_speed = ${common.monitor_speed}
 
 
 [env:emonesp_deploy]
-platform = espressif8266
+platform = espressif8266@1.8.0
 framework = arduino
 board = esp12e
 lib_deps = ${common.lib_deps}
 src_build_flags = !(test -z $TRAVIS_TAG && echo '${common.version}') || echo '-DBUILD_TAG='$TRAVIS_TAG
 
 [env:emonesp01]
-platform = espressif8266
+platform = espressif8266@1.8.0
 framework = arduino
 board = esp01
 lib_deps = ${common.lib_deps}
diff --git a/readme.md b/readme.md
index fcd084f..8a44f17 100644
--- a/readme.md
+++ b/readme.md
@@ -32,6 +32,7 @@ For applications that only require basic posting of data from one emonTx to a re
     + [Save Emoncms server details](#save-emoncms-server-details)
     + [Save Emoncms MQTT server details](#save-emoncms-mqtt-server-details)
   * [Installation](#installation)
+    + [Option 0: Flash using pre-compiled binaries](#flash-precompiled-binaries)
     + [Option 1: Using PlatformIO](#option-1-using-platformio)
       - [1a. Install PlatformIO command line](#1a-install-platformio-command-line)
       - [1b. And / Or use PlatformIO IDE](#1b-and--or-use-platformio-ide)
@@ -199,9 +200,23 @@ Data in string:pairs can be sent to EmonESP via HTTP API. This is useful to emul
 EmonESP uses [ESP8266 Arduino core](https://github.com/esp8266/Arduino)
 
 Firmware can be compiled and uploaded either using PlatfomIO ([see blog post](https://blog.openenergymonitor.org/2016/06/platformio/)) or Arduino IDE.
+Firmware can also be flashed using the pre-compiled binaries using esptool.py.
 
+### Option 0: Flash using pre-compiled binaries
 
-### Option 1: Using PlatformIO
+#### Using EmonUpload
+
+Use our emonupload tool to download latest pre-compiled firmware release and upload to EmonESP: https://github.com/openenergymonitor/emonupload
+
+#### Using Esptool 
+Find and Install [esptool, python required.](https://github.com/espressif/esptool) 
+Navigate to the Releases section of the github page and get the firmware.bin and spiffs.bin files. Use the command below to flash the ESP.
+
+esptool.py --baud 460800 write_flash 0x0 ./firmware.bin 0x300000 ./spiffs.bin
+
+The file paths in the line above are relative, the command is run from the directory where the files are contained, you might need to substitute them for absolute file paths. The 460800 baud can be too high for some programmers, 115200 is a failsafe option.
+
+### Option 1: Compile Using PlatformIO
 
 For more detailed ESP8266 Arduino core specific PlatfomIO notes see: https://github.com/esp8266/Arduino#using-platformio
 
@@ -303,7 +318,7 @@ pio run -t upload --upload-port 172.16.0.80
 ```
 ***
 
-### Option 2: Using Arduino IDE
+### Option 2: Compie Using Arduino IDE
 
 An overview of this process is:
 - Install ESP boards using board manager.
diff --git a/src/arduino_libs/ESPAsyncTCP.zip b/src/arduino_libs/ESPAsyncTCP.zip
new file mode 100644
index 0000000..bbb08e3
Binary files /dev/null and b/src/arduino_libs/ESPAsyncTCP.zip differ
diff --git a/src/arduino_libs/ESPAsyncWebServer.zip b/src/arduino_libs/ESPAsyncWebServer.zip
new file mode 100644
index 0000000..7f2f15a
Binary files /dev/null and b/src/arduino_libs/ESPAsyncWebServer.zip differ
diff --git a/src/arduino_libs/PubSubClient.zip b/src/arduino_libs/PubSubClient.zip
new file mode 100644
index 0000000..a9e84d1
Binary files /dev/null and b/src/arduino_libs/PubSubClient.zip differ
diff --git a/src/arduino_libs/notes.md b/src/arduino_libs/notes.md
new file mode 100644
index 0000000..8c72019
--- /dev/null
+++ b/src/arduino_libs/notes.md
@@ -0,0 +1 @@
+These libraries are for adding to your ArduinoIDE libraries directiory, if required.