Overview Of RFM12 Wireless module

Making wireless devices always is complicated if you want to have your own receiver/transmitter circuit design...working on ISM-band tranceiver circuits needs to have experiences of high frequency courses obviously not simple as low frequency communication circuits...
a good cheap solution is working with RF modules...HopeRF is a chinese company has produced   cheap SPI-based  RF modules for general purposes first time...
first products of hoperf was RFM01 (receiver) and RFM02 (transmiter) FSK modules called as half-duplex devices,main problem was demo program released first time in their datasheets...that still is presented for some projects...finally i decided to switch to RFM12 later full-duplex tranceiver module and could work with it both through AVR and PIC wether in Basic or C language...
i will place a working project in C language (for codevision) in next post...RFM12 is interfaced with  avr  in the project to send temprature read from a LM35 sensor...
for the begining have the pinout image: