Domoticz

Slightly off topic:-

Does anynone know if its possible to use an arduino with a DHT11 or DHT22 to transmit over the 433MHz and recieve using one of the protocols the RFXtrx433E has?
I think someone has tried to emulate the oregon protocol but were using a different type of temp/humidity sensor.

Any ideas?

Oregon (OSV2 or OSV3) are using different sensors:
THGR122NX
THGN132N
THN132N

You do not need to have rfxtrx433e to transfer DHT22 temp/humidity. A simple Arduino nano (£4) or even ATTiny85/45 and transmitter (£2) would be good. Install the 433Mhz receiver on your RPi's SPI and you are good to go. Unfortunately, I do not have much experience with RFXcom so cannot help you with that one.

Sorry I should have said the arduino is controlling a fan and extract unit by differentiating the data from 2 DHT22's, 1 inside and 1 outside, (this is all working) the temp and humidity is displayed on a local TFT screen. I am looking to transmit the data from the arduino to domoticz

Your question is more about transferring data between Arduino and RPi.
Again can be done via 433mhz / 2.4ghz transceiver or/and a combination of a transceiver and rfxtrx433e

Go the MySensors route, this will work fine and is native supported in Domoticz.
Build a MySensors gateway (i have the Ethernet version) and build a temperature/humidity node.

The My sensors route was/is definatley the way forward I have manged to do what i wanted and much more. Have been using this for months now. Many Thanks