Remote temperature sensor system without slave board I want to build a temperature control network over my house reading data from each room and sending it to the main board for further processing. I need about 6 sensor nodes sending the data over the air to the main node.
There are tons of tutorials of making master-slave temperature/pressure etc control systems of 2 Arduino boards communicating via wireless channel.
I find it a bit expensive to have a board per sensor node. Is that possible to build a sensor device without a controller using just a sensor, a battery and a wireless transmitter plus required radio components? It's ok to send raw data to the main node. Assuming it knows the protocol it will be able to decode the data there from all the incoming channels.
As @Majenko said on comment, its possible. One of the choice is ESP8266. Your project has been successfully accomplished, you can check here, here, or here. NSP8266 only needs 3-3.6V (low current) supply voltage.