We here provide code and data for the study "Development of a low cost open-source ultrasonic device for plant height measurements" Code: - Arduino code (management of the electronic circuit): "Arduino_ultrasonic_sensor.ino" - OpenSCAD code (3D-printing): "3DShells_ultrasonic_sensor.scad" - R code (statistical analysis of field test): "Statistical_analysis.R" Data: - "manual_vs_sensor_controlled.csv": this file contains the comparison between the ultrasonic device and the ruler in standardized laboratory conditions. It has three columns: "manual_value", the height value measured manually; "sensor_value", the height value obtained from the ultrasonic device; "height_range", the interval to which the height value belongs (we worked with 25 cm intervals). - "manual_vs_ruler_field.csv": this file contains the comparison between the ultrasonic device and the ruler in field conditions. Plant height measurements were performed on 26 sorghum genotypes. The file has four columns: "Genotype", the id of the measured genotype; "rep" the replicate (3 plants were measured for each genotype); "manual_value", the height value measured manually; "sensor_value", the height value obtained from the ultrasonic device. When using the ruler, the operator spent 15 min and 23 s to complete all measurements in the field, and 3 min and 27 s to enter all data manually in a digital file. When using the sensor, the operator spent 10 min and 52 s to complete all measurements in the field, and manual transcription was not needed since all measurements are instantaneously saved on an SD card. More details on the experimental data can be found in the article "Development of a low cost open-source ultrasonic device for plant height measurements". We also provide a tutorial to explain how to build the ultrasonic-sensor ("tutorial.docx")