modbus_gw is a USB Stick I have created in order to interface wireless 433MHz sensors with Modbus.
It support Oregon Scientific an WT480 temperature sensors. It also has the capability to notify Nexa RF receivers like Nexa switch and Nexa doorbell in order to turn on/off lights or ring the doorbell with different sounds based on events.
I made this dongle initially to supply my Tridium Niagara installation with cheap temperature/humidity sensors around the house.
Contact me if you are interested in adding this kind of sensors to your Niagara installation.