ARDUINO NRF24L01+

need two simple send receive programs for arduino. RF transciever used is NRF24L01+, first program has to send "hello word"(anydata) to reader and must go to sleep mode, then wake up and send again, and so on. second program has to send "hello world" only after receiving a request from reader, program should wake up>start listening>if there is request from reader >send hello world> and go sleep, then wake up and over and over again. so basicaly two algorithms first is called Tag Talks First(is when node sends data autonomously) and second is called Reader Talks First (is when node sends data only after receiving request from reader) 1) wake up>send>sleep>wakeup>..... 2)wake up>listen>if receive>send>sleep//// otherwise sleep>wakeup>...... receiver program control can be implemented by using serial port. for example. I send "1" and then node sends me his hello world.