This paper demonstrates, an autonomous wireless sensor node without need for a battery, harvesting energy from dual source thermal and solar energy with detailed power budgeting and energy harvesting circuits. This sensor node operates from the scavenged ambient energy and capable of doing duty cycled wireless telemetry of sensor data through an IoT gateway to the back end server. Sensor node transfers data to the back end server in lab by configuring RF SoC (Sub-1GHz band) to transmit temperature and battery voltage levels sensed by the on-chip sensors once in every minute, and the sensor data observed through an UDP receive program on a PC.