This paper presents a feasible and a low-cost IoT based monitoring system for precision agriculture, with emphasis to viticulture. A field/crop data are acquired by self-powered measuring station and sent to remote collector, located in the home or office. The collector accepts the data and forward them via home/office WiFi to commercial or open IoT servers (as ThingSpeak) for further visualization, analyze and react back. Using available APIs, any web application on any server can communicate with IoT server, and thus with field station. Every authorized person or farmer, who has computer or gadget with Internet access can monitor parameters of interest and control back associated processes as irrigation or ventilation. Principle of operation, hardware and software architecture as well as preliminary results are shortly elaborated.