Hakim, G., muhammad Hafidz, A. Firdausi, and E. Ramadhan. “Wireless Sensor Network Nodal Development for Low Cost and Low Power PH Soil Monitoring Agriculture 4.0 Application”. Journal FORTEI-JEERI, vol. 1, no. 2, Dec. 2020, pp. 10-18, doi:10.46962/forteijeeri.v1i2.16.