diff --git a/.gitignore b/.gitignore
index 24493c0..36ba001 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,4 +5,5 @@
 .ino*
 Release/
 Prototype/
+OTA/
 .*/
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..be837a7
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "libraries/RF24"]
+	path = libraries/RF24
+	url = https://git.hodos.ro/3rd_party/RF24.git
diff --git a/libraries/RF24 b/libraries/RF24
new file mode 160000
index 0000000..2eff15e
--- /dev/null
+++ b/libraries/RF24
@@ -0,0 +1 @@
+Subproject commit 2eff15e19bb0a3865edc8457a13632a0adf7a913
diff --git a/window1/examples/rf24-sender.ino b/window1/examples/rf24-sender.ino
new file mode 100644
index 0000000..901aa3b
--- /dev/null
+++ b/window1/examples/rf24-sender.ino
@@ -0,0 +1,103 @@
+/*
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+version 2 as published by the Free Software Foundation.
+
+    rf24ping85.ino by tong67 ( https://github.com/tong67 )
+    This is an example of how to use the RF24 class to communicate with ATtiny85 and other node.
+    Write this sketch to an ATtiny85. It will act like the 'transmit' mode of GettingStarted.ino
+    Write GettingStarted.ino sketch to UNO (or other board or RPi) and put the node in 'receiver' mode.
+    The ATtiny85 will transmit a counting number every second starting from 1.
+    The ATtiny85 uses the tiny-core by CodingBadly (https://code.google.com/p/arduino-tiny/)
+    When direct use of 3v3 does not work (UNO boards have bad 3v3 line) use 5v with LED (1.8V ~ 2.2V drop)
+    For low power consumption solutions floating pins (SCK and MOSI) should be pulled high or low with eg. 10K
+
+    ** Hardware configuration **
+    ATtiny25/45/85 Pin map with CE_PIN 3 and CSN_PIN 4
+                                 +-\/-+
+                   NC      PB5  1|o   |8  Vcc --- nRF24L01  VCC, pin2 --- LED --- 5V
+    nRF24L01  CE, pin3 --- PB3  2|    |7  PB2 --- nRF24L01  SCK, pin5
+    nRF24L01 CSN, pin4 --- PB4  3|    |6  PB1 --- nRF24L01 MOSI, pin7
+    nRF24L01 GND, pin1 --- GND  4|    |5  PB0 --- nRF24L01 MISO, pin6
+                                 +----+
+
+    ATtiny25/45/85 Pin map with CE_PIN 3 and CSN_PIN 3 => PB3 and PB4 are free to use for application
+    Circuit idea from http://nerdralph.blogspot.ca/2014/01/nrf24l01-control-with-3-attiny85-pins.html
+    Original RC combination was 1K/100nF. 22K/10nF combination worked better.
+	For best settletime delay value in RF24::csn() the timingSearch3pin.ino scatch can be used.
+    This configuration is enabled when CE_PIN and CSN_PIN are equal, e.g. both 3
+    Because CE is always high the power consumption is higher than for 5 pins solution
+                                                                                            ^^
+                                 +-\/-+           nRF24L01   CE, pin3 ------|              //
+                           PB5  1|o   |8  Vcc --- nRF24L01  VCC, pin2 ------x----------x--|<|-- 5V
+                   NC      PB3  2|    |7  PB2 --- nRF24L01  SCK, pin5 --|<|---x-[22k]--|  LED
+                   NC      PB4  3|    |6  PB1 --- nRF24L01 MOSI, pin6  1n4148 |
+    nRF24L01 GND, pin1 -x- GND  4|    |5  PB0 --- nRF24L01 MISO, pin7         |
+                        |        +----+                                       |
+                        |-----------------------------------------------||----x-- nRF24L01 CSN, pin4
+                                                                       10nF
+
+    ATtiny24/44/84 Pin map with CE_PIN 8 and CSN_PIN 7
+	Schematic provided and successfully tested by Carmine Pastore (https://github.com/Carminepz)
+                                  +-\/-+
+    nRF24L01  VCC, pin2 --- VCC  1|o   |14 GND --- nRF24L01  GND, pin1
+                            PB0  2|    |13 AREF
+                            PB1  3|    |12 PA1
+                            PB3  4|    |11 PA2 --- nRF24L01   CE, pin3
+                            PB2  5|    |10 PA3 --- nRF24L01  CSN, pin4
+                            PA7  6|    |9  PA4 --- nRF24L01  SCK, pin5
+    nRF24L01 MOSI, pin7 --- PA6  7|    |8  PA5 --- nRF24L01 MISO, pin6
+                                  +----+
+*/
+
+// CE and CSN are configurable, specified values for ATtiny85 as connected above
+#define CE_PIN 5
+#define CSN_PIN 3
+//#define CSN_PIN 3 // uncomment for ATtiny85 3 pins solution
+
+#include <RF24.h>
+
+RF24 radio(CE_PIN, CSN_PIN);
+
+byte addresses[][6] = {
+  "1Node","2Node"};
+unsigned long payload = 0;
+
+void setup() {
+  // Setup and configure rf radio
+  radio.begin(); // Start up the radio
+  radio.setAutoAck(1); // Ensure autoACK is enabled
+  radio.setRetries(15,15); // Max delay between retries & number of retries
+  radio.setDataRate(RF24_250KBPS);
+  radio.setPALevel(RF24_PA_LOW);
+  radio.openWritingPipe(addresses[1]); // Write to device address '2Node'
+  radio.openReadingPipe(1,addresses[0]); // Read on pipe 1 for device address '1Node'
+  radio.startListening(); // Start listening
+}
+
+void loop(void){
+
+  radio.stopListening(); // First, stop listening so we can talk.
+  payload++;
+  radio.write( &payload, sizeof(unsigned long) );
+  radio.startListening(); // Now, continue listening
+
+    unsigned long started_waiting_at = micros(); // Set up a timeout period, get the current microseconds
+  boolean timeout = false; // Set up a variable to indicate if a response was received or not
+
+  while ( !radio.available() ){ // While nothing is received
+    if (micros() - started_waiting_at > 200000 ){ // If waited longer than 200ms, indicate timeout and exit while loop
+      timeout = true;
+      break;
+    }
+
+  }
+
+  if ( !timeout ){ // Describe the results
+    unsigned long got_time; // Grab the response, compare, and send to debugging spew
+    radio.read( &got_time, sizeof(unsigned long) );
+  }
+
+  // Try again 1s later
+  delay(1000);
+}