A wireless device for continuous frond elongation measurement

•A novel device, the Palmeter, was developed for continuous frond elongation measurement with high accuracy.•The Palmeter worked stably under varying temperature and wind conditions.•The wireless transmission properties of the Palmeter were determined.•The power consumption of the Palmeter was evaluated, and a six-volt power supply was recommended.•A wireless Palmeter network in a date palm orchard was successfully tested.